Community-Acquired Pneumonia (CAP)


Epidemiology

Prevalence

CDC Etiology of Pneumonia in the Community (EPIC) Study of Community-Acquired Pneumonia (CAP) (JAMA, 2015) [MEDLINE]

  • Incidence
    • Annual Community-Acquired Pneumonia Incidence was 24.8 Cases Per 10k Adults
    • Highest Community-Acquired Pneumonia Rates were Observed Among the 65-79 y/o Age Group (63.0 Cases Per 10k Adults) and Among the ≥80 y/o Age Group (164.3 Cases Per 10k Adults)
    • Community-Acquired Pneumonia Incidence Increased with Age for All of the Pathogens
  • Median Age of Community-Acquired Pneumonia Patients was 57 y/o
  • Pathogen Identification and Distribution
    • A Community-Acquired Pneumonia Pathogen was Detected in 38% of Cases
      • One or More Viruses: 23% of cases
      • Bacteria: 11% of cases
      • Bacterial and Viral Pathogens: 3% of cases
      • Fungal or Mycobacterial Pathogen: 1% of cases
    • Most Common Community-Acquired Pneumonia Pathogens
  • Environment of Care and Prognosis
    • Approximately 21% of Community-Acquired Pneumonia Cases Required ICU Care
    • Overall Mortality Rate was 2%

Predisposing Factors/Epidemiologic Factors Associated with Various Infectious Etiologies of Community-Acquired Pneumonia (Clin Infect Dis, 2007) [MEDLINE]

Advanced Age

  • General Risk
    • Systematic Review of Risk Factors for Community-Acquired Pneumonia in Ambulatory/Hospitalized Adults (Respiration, 2017) [MEDLINE]: n = 29 (20 case-control, 8 cohort, and 1 cross-sectional) with median Newcastle-Ottawa scale score of 7.44 (range 5-9)
      • Factors Associated with an Increased Risk of Community-Acquired Pneumonia
      • Factors Not Associated with an Increased Risk of Community-Acquired Pneumonia

Alcohol Abuse (see Ethanol)

Aspiration

  • Specific Organisms

Asthma (see Asthma)

Bioterrorism

  • Specific Organisms
    • Bacillus Anthracis (Anthrax) (see Anthrax)
    • Francisella Tularensis (Tularemia) (see Tularemia)
    • Yersinia Pestis (Plague) (see Plague)

Chronic Kidney Disease (CKD) (see Chronic Kidney Disease)

  • Specific Organisms
    • Staphylococcus Aureus (see Staphylococcus Aureus)
      • In a Retrospective Study Including Both Community-Acquired and Hospital-Acquired Bacteremic Staphylococcus Aureus Pneumonia, Chronic Kidney Disease was Associated in 31.6% of Cases (Eur J Clin Microbiol Infect Dis, 2016) [MEDLINE]

Chronic Obstructive Pulmonary Disease (COPD) (see Chronic Obstructive Pulmonary Disease)

Cirrhosis (see Cirrhosis)

  • Specific Organisms
    • Staphylococcus Aureus (see Staphylococcus Aureus)
      • Studies Suggest that Cirrhosis is Associated with an Increased Risk for Staphylococcus Aureus Pneumonia in the Hospital Setting (Pulm Med, 2016) [MEDLINE] (Chin Med J (Engl), 2019) [MEDLINE]

Congestive Heart Failure (CHF) (see Congestive Heart Failure)

  • Specific Organisms
    • Staphylococcus Aureus (see Staphylococcus Aureus)
      • In a Retrospective Study Including Both Community-Acquired and Hospital-Acquired Bacteremic Staphylococcus Aureus Pneumonia, Cardiovascular Disease was Associated in 31.6% of Cases (Eur J Clin Microbiol Infect Dis, 2016) [MEDLINE]
    • Streptococcus Pneumoniae (see Streptococcus Pneumoniae) (Thorax, 2015) [MEDLINE]

Corticosteroids (see Corticosteroids)

Cough >2 wks with Whoop or Post-Tussive Emesis

  • Specific Organisms
    • Bordetella Pertussis (Pertussis) (see Pertussis)

Diabetes Mellitus (DM) (see Diabetes Mellitus)

  • General Risk
    • Systematic Review of Risk Factors for CAP in Ambulatory/Hospitalized Adults (Respiration, 2017) [MEDLINE]: n = 29 (20 case-control, 8 cohort, and 1 cross-sectional) with median Newcastle-Ottawa scale score of 7.44 (range 5-9)
      • Factors Associated with an Increased Risk of Community-Acquired Pneumonia
        • Age
        • Asthma (see Asthma)
        • Chronic Obstructive Pulmonary Disease (COPD) (see Chronic Obstructive Pulmonary Disease)
        • Environmental Exposures
        • Functional Impairment
        • Immunosuppressive Therapy
        • Malnutrition
        • Oral Steroids
        • Poor Dental Health
        • Previous CAP
        • Tobacco Smoking (see Tobacco)
        • Treatment with Gastric Acid-Suppressive Medications
      • Factors Not Associated with an Increased Risk of Community-Acquired Pneumonia
        • Alcohol Use (see Ethanol)
        • Cancer
        • Chronic Kidney Disease (CKD) (see Chronic Kidney Disease)
        • Diabetes Mellitus (DM) (see Diabetes Mellitus)
        • Gender
        • Influenza Vaccination
        • Inhalation Therapy
        • Liver Disease (see Cirrhosis)
        • Overweight
        • Pneumococcal Vaccination
        • Recent Respiratory tract infections
        • Swallowing Disorders
    • English Retrospective Cohort Study of Primary Care Patients with/without Type 1/II Diabetes (Diabetes Care, 2018) [MEDLINE]: 102,493 primary care patients (age 40-89 y/o)
      • Risk of Pneumonia (Type I DM): Incidence Rate Ratio 2.98 (95% CI: 2.40–3.69)
      • Risk of Pneumonia (Type II DM): Incidence Rate Ratio 1.58 (95% CI: 1.53–1.64)
    • South Korean National Chort Study (Diabetes Metab J, 2019) [MEDLINE]: n = 66,426 diabetics and 132,852 age/sex/region-matched non-diabetic controls
      • Diabetics Had an Increased Risk of Respiratory Infection (Adjusted Incidence Ratio 1.76; 95% CI: 1.72–1.81)
      • Diabetics Had an Increased Risk of Pneumonia (Adjusted Incidence Ratio Ratio 1.57; 95% CI, 1.52-1.62)
    • Spanish Study of Community-Acquired Pneumonia in Primary Care (BMC Infect Dis, 2019) [MEDLINE]: n = 51,185
      • Approximately 16% of Community-Acquired Pneumonia Patients in the Primary Care Setting Had Diabetes as Comorbidity
  • Specific Organisms
    • Staphylococcus Aureus (see Staphylococcus Aureus)
      • Study of Risk Scoring System to Identify Patients with MRSA Admitted with CAP (BMC Infect Dis, 2013) [MEDLINE]: n = 5975
        • Risk Factors Included Recent Hospitalization or ICU Admission (2 pts), Female Sex with Diabetes (1 pt), Age <30 or >79 (1 pt), Prior Antibiotic Exposure (1 pt), Dementia (1 pt), Cerebrovascular Disease (1 pt), Recent Exposure to a Nursing Home/Long-Term Acute Care Facility/Skilled Nursing Facility (1 pt)
        • Prevalence of MRSA Increased with Increasing Score: Low Risk (0 to 1 pts), Medium Risk (2-5 pts) and High Risk (≥6 pts)
      • In a Retrospective Study Including Both Community-Acquired and Hospital-Acquired Bacteremic Staphylococcus Aureus Pneumonia, Diabetes Mellitus was Associated in 29.6% of Cases (Eur J Clin Microbiol Infect Dis, 2016) [MEDLINE]
      • Studies Suggest that Diabetes Mellitus is Associated with an Increased Risk for Staphylococcus Aureus Pneumonia in the Hospital Setting (Pulm Med, 2016) [MEDLINE] (Chin Med J-Engl, 2019) [MEDLINE]
    • Streptococcus Pneumoniae (see Streptococcus Pneumoniae)
      • Diabetes Mellitus Increases the Risk of Pneumococcal Disease (Thorax, 2015) [MEDLINE]
  • Protective Effects of Specific Treatment Regimens for Diabetes Mellitus
    • Patients with Type 2 Diabetes Taking Sodium-Glucose Cotransporter-2 (SGLT2) Inhibitors are at Decreased Risk for Pneumonia and Sepsis, as Compared to Those Taking Dipeptidyl Peptidase-4 (DPP-4) Inhibitors (Diabetes Metab, 2022) [MEDLINE] (see Sodium-Glucose Cotransporter-2 Inhibitors and Dipeptidyl Peptidase-4 Inhibitors)
    • In VA Retrospective Cohort Studies (n = 34,759), Patients with Diabetes Taking Metformin and Who are Hospitalized with Pneumonia were Demonstrated to Be at Decreased Risk of Mortality (Clin Infect Dis, 2022) [MEDLINE] (see Metformin)
      • Unadjusted 30-Day Mortality was 9.6% for Patients Who Had Received Metformin vs 13.9% in Patients Who Had Not Received Metformin (P < 0.003)
      • Unadjusted 90-Day Mortality was 15.8% for Patients Who Had Received Metformin vs 23.0% for Patients Who Had Not Received Metformin (P < 0.0001)
      • After Propensity Matching, Both 30-day (Relative Risk 0.86; 95% CI 0.78-0.95) and 90-Day (Relative Risk 0.85; 95% CI: 0.79-0.92) Mortality was Significantly Lower for Metformin Users

Endobronchial Obstruction

Exposure to Bat/Bird Droppings

  • Specific Organisms

Exposure to Birds

Exposure to Farm Animals/Parturient Cats

  • Specific Organisms
    • Q Fever (Coxiella Burnetti) (see Q Fever)

Exposure to Guinea Pigs

Exposure to Rabbits

  • Specific Organisms
    • Francisella Tularensis (Tularemia) (see Tularemia)

Exposure to Invasive Mechanical Ventilation (see Invasive Mechanical Ventilation-General)

Human Immunodeficiency Virus (HIV) (see Human Immunodeficiency Virus)

Influenza Active in Community

Intravenous Drug Abuse (IVDA) (see Intravenous Drug Abuse)

Lung Abscess (see Lung Abscess)

Organ Failure

Structural Lung Disease (Bronchiectasis, etc)

Tobacco Abuse (see Tobacco)

  • General Risk
    • Systematic Review of Risk Factors for CAP in Ambulatory/Hospitalized Adults (Respiration, 2017) [MEDLINE]: n = 29 (20 case-control, 8 cohort, and 1 cross-sectional) with median Newcastle-Ottawa scale score of 7.44 (range 5-9)
      • Factors Associated with an Increased Risk of CAP
        • Age
        • Asthma (see Asthma)
        • Chronic Obstructive Pulmonary Disease (COPD) (se eChronic Obstructive Pulmonary Disease)
        • Environmental Exposures
        • Functional Impairment
        • Immunosuppressive Therapy
        • Malnutrition
        • Oral Steroids
        • Poor Dental Health
        • Previous CAP
        • Tobacco Smoking (see Tobacco)
        • Treatment with Gastric Acid-Suppressive Medications
      • Factors Not Associated with an Increased Risk of CAP
        • Alcohol Use (see Ethanol)
        • Cancer
        • Chronic Kidney Disease (CKD) (see Chronic Kidney Disease)
        • Diabetes Mellitus (DM) (see Diabetes Mellitus)
        • Gender
        • Influenza Vaccination
        • Inhalation Therapy
        • Liver Disease (see Cirrhosis)
        • Overweight
        • Pneumococcal Vaccination
        • Recent Respiratory tract infections
        • Swallowing Disorders
    • Systematic Review and Meta-Analysis of the Effect of Tobacco Smoking on the Risk of Developing Community-Acquired Pneumonia (PLoS One, 2019) [MEDLINE]: n = 27 studies
      • Current Smokers (Pooled OR 2.17, 95% CI: 1.70-2.76, n = 13 Studies; Pooled HR 1.52, 95% CI: 1.13-2.04, n = 7 Studies) and Ex-Smokers (Pooled OR 1.49, 95% CI: 1.26-1.75, n = 8 Studies; Pooled HR 1.18, 95% CI: 0.91-1.52, n = 6 Studies) Had an Increased Risk of Developing CAP, as Compared to Never Smokers
      • Dose-Response Analyses of Data from 5 Studies Indicated a Significant Trend, Such that Current Smokers Who Smoked a Higher Amount of Tobacco Had a Higher CAP Risk
      • Although the Association Between Passive Smoking and Risk of CAP in Adults of All Ages was Not Statistically Significant (Pooled OR 1.13, 95% CI: 0.94-1.36, n = 5 Studies), Passive Smoking in Adults ≥65 y/o was Associated with a 64% Increased CAP Risk (Pooled OR 1.64; 95% CI: 1.17-2.30, n = 2 Studies)
  • Specific Organisms

Travel to Hotel or on Cruise Ship Stay within 2 wks

Travel to Middle East within 2 wks

Travel to or Residence in Southeast and East Asia

Travel to or Residence in Southwestern United States

Water Colonization

Microbiology

General

Study of the Most Common Etiologies of Community-Acquired Pneumonia (Clin Infect Dis, 2007) [MEDLINE]

CDC Etiology of Pneumonia in the Community (EPIC) Study of Community-Acquired Pneumonia (CAP) (JAMA, 2015) [MEDLINE]

Viral

Bacterial

Fungal

Parasitic

  • Echinococcosis (see Echinococcosis)
    • Etiology
      • Echinococcus
  • Paragonimiasis (see Paragonimiasis)
    • Etiology
      • Paragonimus Westermani and Other Paragonimus Species
  • Strongyloidiasis (see Strongyloidiasis)
    • Etiology
      • Strongyloides

Diagnosis

General Comments Regarding Diagnostic Testing for Patients with Community-Acquired Pneumonia (CAP)

Recommendations (American Thoracic Society and Infectious Diseases Society of America 2007 Consensus Guidelines on the Management of Community-Acquired Pneumonia in Adults) (Clin Infect Dis, 2007) [MEDLINE]

  • Patients with Community-Acquired Pneumonia Should Undergo Diagnostic Testing to Detect Specific Suspected Pathogens that Would Significantly Alter the Choice of Empiric Antibiotic Therapy (Strong Recommendation, Level II Evidence)
  • Routine Diagnostic Testing to Identify an Etiologic Organism in Outpatients with Community-Acquired Pneumonia is Optional (Moderate Recommendation, Level III Evidence)

Erythrocyte Sedimentation Rate (ESR) (see Erythrocyte Sedimentation Rate)

Clinical Efficacy

  • Dutch Cross-Sectional Study of Symptoms, Signs, Erythrocyte Sedimentation Rate, C-Reactive Protein in the Diagnosis of Pneumonia by Outpatient General Practitioners (Br J Gen Pract, 2003) [MEDLINE]: n= 246 presenting with lower respiratory tract infection
    • Dry Cough, Diarrhea, and T >38 Degrees C were Statistically Significant Predictors of Pneumonia
    • Pulmonary Auscultation and Clinical Diagnosis of Pneumonia by the General Practitioner were Not Statistically Significant Predictors of Pneumonia
    • Erythrocyte Sedimentation Rate and C-Reactive Protein Had Higher Diagnostic Odds Ratios than Any of the Symptoms
    • Adding C-Reactive Protein to the Final Symptoms and Signs Model Significantly Increase the Probability of Correct Diagnosis
    • Applying a Prediction Rule for Low-Risk Patients (Including a C-Reactive Protein <20 mg/dL), 80 of the 193 Antibiotic Prescriptions Could Have Been Prevented with a Maximum Risk of 2.5% of Missing a Pneumonia Case

C-Reactive Protein (CRP) (see C-Reactive Protein)

Clinical Efficacy

  • Dutch Cross-Sectional Study of Symptoms, Signs, Erythrocyte Sedimentation Rate, C-Reactive Protein in the Diagnosis of Pneumonia by Outpatient General Practitioners (Br J Gen Pract, 2003) [MEDLINE]: n= 246 presenting with lower respiratory tract infection
    • Dry Cough, Diarrhea, and T >38 Degrees C were Statistically Significant Predictors of Pneumonia
    • Pulmonary Auscultation and Clinical Diagnosis of Pneumonia by the General Practitioner were Not Statistically Significant Predictors of Pneumonia
    • Erythrocyte Sedimentation Rate and C-Reactive Protein Had Higher Diagnostic Odds Ratios than Any of the Symptoms
    • Adding C-Reactive Protein to the Final Symptoms and Signs Model Significantly Increase the Probability of Correct Diagnosis
    • Applying a Prediction Rule for Low-Risk Patients (Including a C-Reactive Protein <20 mg/dL), 80 of the 193 Antibiotic Prescriptions Could Have Been Prevented with a Maximum Risk og 2.5% of Missing a Pneumonia Case

Serum Procalcitonin (see Serum Procalcitonin)

Rationale

  • Serum Procalcitonin is the Peptide Precursor of Calcitonin Which is Released by Parenchymal Cells in Response to Bacterial Toxins
    • Serum Procalcitonin is Elevated in Bacterial Infections
    • Serum Procalcitonin is Downregulated in Viral Infections

Clinical Efficacy

  • Cochrane Database Systematic Review and Meta-Analysis of Using Serum Procalcitonin to Start or Stop Antibiotics in Acute Respiratory Tract Infection (Cochrane Database Syst Rev, 2017) [MEDLINE]
    • Use of Serum Procalcitonin to Guide Initiation and Duration of Antibiotics Results in Lower Risks of Mortality, Lower Antibiotic Consumption, and Lower Risk of Antibiotic-Associated Adverse Effects
    • Results were Similar for Different Clinical Settings and Types of Acute Respiratory Tract Infections
    • Future Research is Required to Confirm the Results in Immunocompromised Patients and Patients with Non-Respiratory Infections
  • Prospective Multicenter Study of the Ability of Serum Procalcitonin to Differentiate Viral vs Bacterial Pneumonia at Hospital Admission (Clin Infect Dis, 2017) [MEDLINE]: n = 1,735
    • Median Procalcitonin Concentration was Lower with Viral Pathogens (0.09 ng/mL; Interquartile Range <0.05-0.54 ng/mL) than Atypical Bacteria (0.20 ng/mL; Interquartile Range <0.05-0.87 ng/mL; P = 0.05), and Typical Bacteria (2.5 ng/mL; IQR, 0.29-12.2 ng/mL; P < 0.01)
    • Procalcitonin Discriminated Bacterial Pathogens, Including Typical and Atypical Bacteria, from Viral Pathogens with an Area Under the Receiver Operating Characteristic Curve of 0.73 (95% CI: 0.69-0.77)
    • A Procalcitonin Threshold of 0.1 ng/mL Resulted in 80.9% (95% CI, 75.3%-85.7%) Sensitivity and 51.6% (95% CI, 46.6%-56.5%) Specificity for Identification of Any Bacterial Pathogen
    • Procalcitonin Discriminated Between Typical Bacteria and the Combined Group of Viruses and Atypical Bacteria with an Area under the Receiver Operating Characteristic Curve of 0.79 (95% CI: 0.75-0.82)
    • In Conclusion, No Procalcitonin Threshold Perfectly Discriminated Between Viral and Bacterial Pathogens, But Higher Procalcitonin Strongly Correlated with Increased Probability of Bacterial Pathogens (Particularly Typical Bacteria)
  • Meta-Analysis of Serum Procalcitonin in Acute Respiratory Tract Infection (Lancet Infect Dis, 2018) [MEDLINE] (Lancet Infect Dis, 2018) [MEDLINE]
    • Reported Sensitivity of Serum Procalcitonin to Detect Bacterial Infection Ranges from 38-91%, Underscoring that This Test Alone Cannot Be Used to Justify Withholding Antibiotics from Patients with Community-Acquired Pneumonia
  • ProACT Trial of Procalcitonin Use for Suspected Lower Respiratory Tract Infection (NEJM, 2018) [MEDLINE]: n = 1656
    • The Provision of Procalcitonin Assay Results, Along with Instructions on Their Interpretation, to Emergency Department and Hospital-Based Clinicians Did Not Result in Less Use of Antibiotics Than Did Usual Care Among Patients with Suspected Lower Respiratory Tract Infection

Recommendations (American Thoracic Society and Infectious Diseases Society of America 2019 Clinical Practice Guidelines for the Diagnosis and Treatment of Adults with Community-Acquired Pneumonia) (Am J Respir Crit Care Med, 2019) [MEDLINE]

  • Empiric Antibiotic Therapy Should Be Initiated in Adults with Clinically Suspected and Radiographically Confirmed Community-Acquired Pneumonia, Regardless of Initial Serum Procalcitonin Level (Strong Recommendation, Moderate Quality of Evidence)

Chest X-Ray (CXR) (see Chest X-Ray)

Radiographic Findings

Clinical Efficacy

  • Army Medical Center Emergency Department Study of the Diehr Rule for the Prediction of Pneumonia in Patients Presenting with Acute Cough (J Chronic Dis, 1984) [MEDLINE]: n = 1,819
    • Pneumonia was Radiographically Diagnosed in 2.6% of the Patients
    • Clinical Decision Rule (Validated in 483 Patients)
      • Rhinorrhea: -2 point
      • Sore Throat: -1 point
      • Night Sweats/Myalgias/All-Day Sputum Production: 1 point
      • Respiratory Rate >25 breaths/min: 2 points
      • T >100 °F (37.8 °C)
    • Interpretation of Score
      • Score of -2 to -3 Points: likelihood of pneumonia was<1%
      • Score of 3-6 Points: likelihood of pneumonia was 27%
  • Emergency Department Study of Gennis Rule for the Diagnosis of Pneumonia (J Emerg Med, 1989) [MEDLINE]: n= 308
    • 38% of the Patients Had Radiographic Pneumonia
    • Symptoms
      • No Single Symptom or Sign was Reliably Predictive of Pneumonia
      • Cough was the Most Common Symptom (Present in 86% of Cases, But was Equally Common in Patients without Pneumonia)
      • Fever was Absent in 31% of Patients with Pneumonia
      • Abnormal Lung Exam (Rales, Rhonchi, Decreased Breath Sounds, Wheezes, Altered Fremitus, Egophony, Dullness to Percussion) were Found in <50% of the Patients with Pneumonia and 22% of Patients with a Completely Normal Lung Exam Had Pneumonia
    • Rule Criteria for Obtaining a Chest X-Ray, Based on Presence of At Least One of the Following (97% Sensitivity)
      • Temperature >100 °F (37.8 °C)
      • Heart Rate >100 beats/min
      • Respiratory Rate >20 breaths/min
  • Emergency Department Prospective Observational Study of Singal Rule for the Diagnosis of Pneumonia (Ann Emerg Med, 1989) [MEDLINE]: n = 255 adults
    • 15.6% of Adult Patients Had Radiographic Pneumonia
    • Univariate Predictors of Pneumonia were Fever, Cough, Crackles
      • In Absence of Fever, Cough, and Crackles, Incidence of Pneumonia was Only 4.3%
  • Emergency Department Study of the Heckerling Rule for the Diagnosis of Pneumonia (Ann Intern Med, 1990) [MEDLINE]: n= 1,436 (3 different emergency departments)
    • Rule was Developed in 1,134 Patients and Validated in 302 Patients
    • Rule Criteria for Obtaining a Chest X-Ray (from Stepwise Logistic Regression Model; p <0.001)
      • Temperature >100 °F (37.8 °C): 1 point
      • Heart Rate >100 beats/min: 1 point
      • Crackles: 1 point
      • Decreased Breath Sounds (Locally): 1 point
      • Absence of Asthma: 1 point
    • Interpretation of Score (Pre-Test Probability was 5% in Primary Care and 15% in Emergency Department)
      • Score 0
        • Post-Test Probability of Pneumonia (Primary Care): 1%
        • Post-Test Probability of Pneumonia (Emergency Department): 2%
        • Likelihood Ratio: 0.12
      • Score 1
        • Post-Test Probability of Pneumonia (Primary Care): 1%
        • Post-Test Probability of Pneumonia (Emergency Department): 3%
        • Likelihood Ratio: 0.2
      • Score 2
        • Post-Test Probability of Pneumonia (Primary Care): 4%
        • Post-Test Probability of Pneumonia (Emergency Department): 11%
        • Likelihood Ratio: 0.7
      • Score 3
        • Post-Test Probability of Pneumonia (Primary Care): 8%
        • Post-Test Probability of Pneumonia (Emergency Department): 22%
        • Likelihood Ratio: 1.6
      • Score 4
        • Post-Test Probability of Pneumonia (Primary Care): 27%
        • Post-Test Probability of Pneumonia (Emergency Department): 56%
        • Likelihood Ratio: 7.2
      • Score 5
        • Post-Test Probability of Pneumonia (Primary Care): 47%
        • Post-Test Probability of Pneumonia (Emergency Department): 75%
        • Likelihood Ratio: 17
    • Rule Had a Receiver Operating Characteristic (ROC) Area 0.82
      • In the Validation Sets, the Rule Discriminated Pneumonia and Non-Pneumonia with ROC Areas of 0.82 and 0.76 (After Adjusting for Differences in Disease Prevalence)
  • Comparative Prospective Study of Diehr/Gennis/Heckerling/Singal Rules with Physician Judgement for the Diagnosis of Pneumonia in Emergency Department and Outpatient Settings (Ann Emerg Med, 1991) [MEDLINE]: n = 290
    • All Patients Had an Acute Cough and Fever, Hemoptysis, or Sputum Production
    • 7% of Patients Had Radiographic Pneumonia (6% in Outpatient Setting, 10% in Emergency Department)
    • Performance
      • Physician Judgement: 86% sensitivity/58% specificity
      • Diehr Rule: 67% sensitivity/67% specificity
      • Gennis Rule: 62% sensitivity/76% specificity
      • Heckerling Rule: 71% sensitivity/67% specificity
      • Singal Rule: 76% sensitivity/55% specificity

Recommendations (American Academy of Family Physicians/AAFP Point-of-Care Guidelines) (Am Fam Physician, 2007) [MEDLINE]

  • Simple Rule for Determining the Need for Chest Radiography in Patients with Acute Respiratory Illness
    • Chest Radiography Should Be Performed if Either of the Following are Present
      • Presence of One of the Following
        • T >100 °F (37.8 °C)
        • Heart Rate >100 Beats/min
        • Respiratory Rate >20 Breaths/min
      • Presence of Two of the Following
        • Absence of Asthma
        • Crackles (Rales)
        • Decreased Breath Sounds

Recommendations (American Thoracic Society and Infectious Diseases Society of America 2007 Consensus Guidelines on the Management of Community-Acquired Pneumonia in Adults) (Clin Infect Dis, 2007) [MEDLINE]

  • Demonstrable Infiltrate by Chest X-Ray or Chest CT (with/without Supporting Microbiologic Data) is Required for the Diagnosis of Pneumonia (Moderate Recommendation, Level III Evidence)

Chest Computed Tomography (Chest CT) (see Chest Computed Tomography)

Radiographic Findings

  • Alveolar and/or Interstitial Infiltrates
  • Chest CT has Higher Sensitivity for the Detection of Infiltrates than Chest X-Ray

Recommendations (American Thoracic Society and Infectious Diseases Society of America 2007 Consensus Guidelines on the Management of Community-Acquired Pneumonia in Adults) (Clin Infect Dis, 2007) [MEDLINE]

  • Demonstrable Infiltrate by Chest X-Ray or Chest CT (with/without Supporting Microbiologic Data) is Required for the Diagnosis of Pneumonia (Moderate Recommendation, Level III Evidence)

Blood Cultures (see Blood Culture)

Clinical Efficacy

  • In the Outpatient Setting, Yield of Blood Cultures in Patients with Community-Acquired Pneumonia is 2% (Am J Respir Crit Care Med, 2019) [MEDLINE]
  • In the Inpatient Setting, Yield of Blood Cultures in Patients with Community-Acquired Pneumonia is 9% (Am J Respir Crit Care Med, 2019) [MEDLINE]

Recommendations (American Thoracic Society and Infectious Diseases Society of America 2007 Consensus Guidelines on the Management of Community-Acquired Pneumonia in Adults) (Clin Infect Dis, 2007) [MEDLINE]

Recommendations (American Thoracic Society and Infectious Diseases Society of America 2019 Clinical Practice Guidelines for the Diagnosis and Treatment of Adults with Community-Acquired Pneumonia) (Am J Respir Crit Care Med, 2019) [MEDLINE]

  • In the Outpatient Setting, Blood Cultures are Not Recommended in Adults with Community-Acquired Pneumonia (Strong Recommendation, Very Low Quality of Evidence)
  • In the Inpatient Setting, Blood Cultures are Not Routinely Recommended in Adults with Community-Acquired Pneumonia (Conditional Recommendation, Very Low Quality of Evidence)
  • Indications for Blood Cultures (Any of the Following)
    • Empiric Treatment for Either Methicillin-Resistant Staphylococcus Aureus (MRSA) or Pseudomonas Aeruginosa (Strong Recommendation, Very Low Quality of Evidence)
    • Prior Infection with Methicillin-Resistant Staphylococcus Aureus (MRSA) or Pseudomonas Aeruginosa (Especially Prior Respiratory Tract Infection) (Conditional Recommendation, Very Low Quality of Evidence)
      • These are the Strongest Risk Factors for Methicillin-Resistant Staphylococcus Aureus (MRSA) or Pseudomonas Aeruginosa Community-Acquired Pneumonia
    • Prior Hospitalization or Receipt of Parenteral Antibiotics within the Last 90 Days (Conditional Recommendation, Very Low Quality of Evidence)
      • These Factors Increase the Risk of Methicillin-Resistant Staphylococcus Aureus (MRSA) or Pseudomonas Aeruginosa Community-Acquired Pneumonia
    • Severe Community-Acquired Pneumonia (Especially if the Patient is Intubated), as Defined by the Following (Strong Recommendation, Very Low Quality of Evidence)
      • General Comments
        • Validated Definition of Severe Community-Acquired Pneumonia Includes Either 1 Major Criterion or ≥3 Minor Criteria
      • Major Criteria
        • Respiratory Failure Requiring Invasive Mechanical Ventilation
        • Septic Shock Requiring Vasopressors
      • Minor Criteria
        • Altered Mental Status
        • Hypotension Requiring Aggressive Intravenous Fluid Resuscitation
        • Hypothermia (Core Temperature <36°C)
        • Leukopenia (WBC <4000 Cells/mm3)
        • Multilobar Infiltrates
        • pO2/FiO2 Ratio ≤250
        • Tachypnea (Respiratory Rate ≥30 Breaths/min)
        • Thrombocytopenia (Platelets <100k Cells/mm3)
        • Uremia (BUN ≥20 mg/dL)

Sputum Gram Stain/Culture (see Sputum Culture)

Technique

  • Specimen Source
    • Endotracheal Tube Aspirate: when patient is intubated
    • Expectorated Sputum Culture: when patient is not intubated
  • Procedures
    • Bacterial Gram Stain and Culture
    • Fungal Stain and Culture: recommended for patient with cavitary infiltrates, etc
    • Acid Fast Bacterial (AFB) Stain and Culture: recommended for patient with cavitary infiltrates, etc

Clinical Efficacy

  • In Patients with Community-Acquired Pneumonia Who Have Been Newly Intubated, Endotracheal Aspirate Has a Better Yield (Yield >50%) of Microbiological Organisms Than Sputum Culture (Ann Am Thorac Soc, 2016) [MEDLINE]

Recommendations (American Thoracic Society and Infectious Diseases Society of America 2007 Consensus Guidelines on the Management of Community-Acquired Pneumonia in Adults) (Clin Infect Dis, 2007) [MEDLINE]

Recommendations (American Thoracic Society and Infectious Diseases Society of America 2019 Clinical Practice Guidelines for the Diagnosis and Treatment of Adults with Community-Acquired Pneumonia) (Am J Respir Crit Care Med, 2019) [MEDLINE]

  • Indications for Sputum Gram Stain/Culture (Any of the Following)
    • Empiric Treatment for Either Methicillin-Resistant Staphylococcus Aureus (MRSA) or Pseudomonas Aeruginosa (Strong Recommendation, Very Low Quality of Evidence)
    • Prior Infection with Methicillin-Resistant Staphylococcus Aureus (MRSA) or Pseudomonas Aeruginosa (Especially Prior Respiratory Tract Infection) (Conditional Recommendation, Very Low Quality of Evidence)
      • These are the Strongest Risk Factors for Methicillin-Resistant Staphylococcus Aureus (MRSA) or Pseudomonas Aeruginosa Community-Acquired Pneumonia
    • Prior Hospitalization or Receipt of Parenteral Antibiotics within the Last 90 Days (Conditional Recommendation, Very Low Quality of Evidence)
      • These Factors Increase the Risk of Methicillin-Resistant Staphylococcus Aureus (MRSA) or Pseudomonas Aeruginosa Community-Acquired Pneumonia
    • Severe Community-Acquired Pneumonia (Especially if the Patient is Intubated), as Defined by the Following (Strong Recommendation, Very Low Quality of Evidence)
      • General Comments
        • Validated Definition of Severe Community-Acquired Pneumonia Includes Either 1 Major Criterion or ≥3 Minor Criteria
      • Major Criteria
        • Respiratory Failure Requiring Invasive Mechanical Ventilation
        • Septic Shock Requiring Vasopressors
      • Minor Criteria
        • Altered Mental Status
        • Hypotension Requiring Aggressive Intravenous Fluid Resuscitation
        • Hypothermia (Core Temperature <36°C)
        • Leukopenia (WBC <4000 Cells/mm3)
        • Multilobar Infiltrates
        • pO2/FiO2 Ratio ≤250
        • Tachypnea (Respiratory Rate ≥30 Breaths/min)
        • Thrombocytopenia (Platelets <100k Cells/mm3)
        • Uremia (BUN ≥20 mg/dL)

Nasal Methicillin-Resistant Staphylococcus Aureus (MRSA) Testing (see Nasal Methicillin-Resistant Staphylococcus Aureus Testing)

Clinical Efficacy

  • Data Supporting the Negative Predictive Value of Rapid Methicillin-Resistant Staphylococcus Aureus (MRSA) Testing are Robust (American Thoracic Society and Infectious Diseases Society of America 2019 Clinical Practice Guidelines for the Diagnosis and Treatment of Adults with Community-Acquired Pneumonia) (Am J Respir Crit Care Med, 2019) [MEDLINE]
    • Treatment for Methicillin-Resistant Staphylococcus Aureus (MRSA) Pneumonia Can Generally Be Withheld When the Nasal Methicillin-Resistant Staphylococcus Aureus (MRSA) Swab is Negative, Especially in Non-Severe Community-Acquired Pneumonia
    • However, the Positive Predictive Value of Methicillin-Resistant Staphylococcus Aureus (MRSA) Culture is Not as High
      • Therefore, When the Nasal Methicillin-Resistant Staphylococcus Aureus (MRSA) Swab is Positive, Coverage for Methicillin-Resistant Staphylococcus Aureus (MRSA) Pneumonia Should Generally Be Initiated (In the Specific Clinical Situations Noted Below), But Blood/Sputum Cultures Should Be Obtained and Therapy Deescalated if Cultures are Negative

Urinary Histoplasma Antigen (see Urinary Histoplasma Antigen)

  • May Be Indicated in Select Cases

Legionella Testing

Techniques

  • Urinary Legionella Antigen (see Urinary Legionella Antigen)
    • Urinary Legionella Antigen Remains Positive for Days After the Start of Antibiotic Treatment
  • Endotracheal Aspirate/Bronchoalveolar Lavage (BAL) Legionella Culture on Selective Media
  • Legionella Direct Fluorescent Antigen (DFA) (see Legionella Direct Fluorescent Antigen)
  • Legionella Polymerase Chain Reaction (PCR) Test

Recommendations (American Thoracic Society and Infectious Diseases Society of America 2007 Consensus Guidelines on the Management of Community-Acquired Pneumonia in Adults) (Clin Infect Dis, 2007) [MEDLINE]

  • Indications for Urinary Legionella Antigen Testing
    • Active Alcohol Abuse (see Ethanol)
    • Failure of Outpatient Antibiotic Therapy
    • Intensive Care Unit (ICU) Admission
    • Pleural Effusion (see Pleural Effusion-General)
    • Recent Travel within the Past 2 wks

Recommendations (American Thoracic Society and Infectious Diseases Society of America 2019 Clinical Practice Guidelines for the Diagnosis and Treatment of Adults with Community-Acquired Pneumonia) (Am J Respir Crit Care Med, 2019) [MEDLINE]

  • Routine Urine Legionella Antigen Testing is Not Recommended in Adults with Community-Acquired Pneumonia (Conditional Recommendation, Low Quality of Evidence)
  • Urine Legionella Antigen Testing is Recommended in Adults with Community-Acquired Pneumonia with Either of the Following
    • Presence of Either Epidemiologic Risk Factors for Legionella (Conditional Recommendation, Low Quality of Evidence
      • Association with Legionella Outbreak
      • Recent Travel
    • Severe Community-Acquired Pneumonia (Especially if the Patient is Intubated), as Defined by the Following (Conditional Recommendation, Low Quality of Evidence
      • General Comments
        • Validated Definition of Severe Community-Acquired Pneumonia Includes Either 1 Major Criterion or ≥3 Minor Criteria
      • Major Criteria
        • Respiratory Failure Requiring Invasive Mechanical Ventilation
        • Septic Shock Requiring Vasopressors
      • Minor Criteria
        • Altered Mental Status
        • Hypotension Requiring Aggressive Intravenous Fluid Resuscitation
        • Hypothermia (Core Temperature <36°C)
        • Leukopenia (WBC <4000 Cells/mm3)
        • Multilobar Infiltrates
        • pO2/FiO2 Ratio ≤250
        • Tachypnea (Respiratory Rate ≥30 Breaths/min)
        • Thrombocytopenia (Platelets <100k Cells/mm3)
        • Uremia (BUN ≥20 mg/dL)
  • In Adults with Severe Community-Acquired Pneumonia, Legionella Testing Should Consist of Both of the Following (Conditional Recommendation, Low Quality of Evidence)
    • Urinary Legionella Antigen Test (see Urinary Legionella Antigen)
    • Lower Respiratory Tract Specimen with Legionella Culture on Selective Media or Legionella Polymerase Chain Reaction (PCR) Test

Urinary Pneumococcal Antigen (see Urinary Pneumococcal Antigen)

Technique

  • Urinary Pneumococcal Antigen Remains Positive for Days After the Start of Antibiotic Treatment

Recommendations (American Thoracic Society and Infectious Diseases Society of America 2007 Consensus Guidelines on the Management of Community-Acquired Pneumonia in Adults) (Clin Infect Dis, 2007) [MEDLINE]

Recommendations (American Thoracic Society and Infectious Diseases Society of America 2019 Clinical Practice Guidelines for the Diagnosis and Treatment of Adults with Community-Acquired Pneumonia) (Am J Respir Crit Care Med, 2019) [MEDLINE]

  • Routine Urine Pneumococcal Antigen Testing is Not Recommended in Adults with Community-Acquired Pneumonia (Conditional Recommendation, Low Quality of Evidence)
  • Urine Pneumococcal Antigen Testing is Recommended in Adults with Severe Community-Acquired Pneumonia, as Defined by the Following (Conditional Recommendation, Low Quality of Evidence)
    • General Comments
      • Validated Definition of Severe Community-Acquired Pneumonia Includes Either 1 Major Criterion or ≥3 Minor Criteria
    • Major Criteria
      • Respiratory Failure Requiring Invasive Mechanical Ventilation
      • Septic Shock Requiring Vasopressors
    • Minor Criteria
      • Altered Mental Status
      • Hypotension Requiring Aggressive Intravenous Fluid Resuscitation
      • Hypothermia (Core Temperature <36°C)
      • Leukopenia (WBC <4000 Cells/mm3)
      • Multilobar Infiltrates
      • pO2/FiO2 Ratio ≤250
      • Tachypnea (Respiratory Rate ≥30 Breaths/min)
      • Thrombocytopenia (Platelets <100k Cells/mm3)
      • Uremia (BUN ≥20 mg/dL)

Nasal Influenza Testing (see Influenza Virus)

Background

  • Study Examining the Use of Influenza Testing in US Hospitals from 2010-2015 (Chest, 2022) [MEDLINE]: n = 166,268 patients with community-acquired pneumonia (data from 179 Hospitals in the Premier Database)
    • Only 35.6% of the Community-Acquired Pneumonia Patients were Tested for Influenza
      • Interestingly, the Rates of Influenza Testing were Low Even During Influenza Season
    • Influenza-Positive Patients Received Antiviral Agents More Often and Antibacterial Agents Less Often and for Shorter Courses than Influenza-Negative Patients (5.3 vs 6.4 Days; P < 0.001)
    • Influenza-Positive Patients Receiving Oseltamivir on Hospital Day 1 (n = 2,585) Had a Lower 14-Day In-Hospital Mortality Rate (Adjusted Odds Ratio 0.75; 95% CI: 0.59-0.96), Lower Costs (Adjusted Ratio of Means 0.88; 95% CI: 0.81-0.95), and Shorter Length of Stay (Adjusted Ratio of Means 0.88; 95% CI: 0.84-0.93) vs Patients Receiving Oseltamivir Later or Not at All (n = 1,742)

Recommendations (American Thoracic Society and Infectious Diseases Society of America 2019 Clinical Practice Guidelines for the Diagnosis and Treatment of Adults with Community-Acquired Pneumonia) (Am J Respir Crit Care Med, 2019) [MEDLINE]

  • In the Setting of Community-Acquired Pneumonia, When Influenza Viruses are Circulating in the Community, Testing for Influenza with a Rapid Influenza Molecular Assay (i.e. Influenza Nucleic Acid Amplification Test) is Recommended Over a Rapid Influenza Diagnostic Test (i.e. Antigen Test) (Strong Recommendation, Moderate Quality of Evidence
    • The Benefits of Antiviral Therapy Support Testing of Patients During Periods of High Influenza Activity
    • During Periods of Low Influenza Activity in the Community, Testing Can Be Considered, But May Not Be Routinely Performed

Recommendations for Diagnostic Testing for Influenza (Clinical Practice Guidelines by the Infectious Diseases Society of America: 2018 Update on Diagnosis, Treatment, Chemoprophylaxis, and Institutional Outbreak Management of Seasonal Influenza) (Clin Infect Dis, 2019) [MEDLINE]

Which Patients Should Be Tested for Influenza
  • Outpatients (including the Emergency Department)
    • During Influenza Activity (Defined as the Circulation of Seasonal Influenza A/B Viruses in the Local Community)
      • Clinicians Should Test for Influenza in High-Risk Patients, Including Immunocompromised Patients Who Present with Influenza-Like Illness, Pneumonia, or Nonspecific Respiratory Illness (i.e. Cough without Fever) if the Testing Result Will Influence Clinical Management (A–III)
      • Clinicians Should Test for Influenza in Patients Who Present with Acute Onset of Respiratory Symptoms with/without Fever, and Either Exacerbation of Chronic Medical Conditions (Asthma, Chronic Obstructive Pulmonary Disease, Heart Failure) or Known Complications of Influenza (Pneumonia) if the Testing Result Will Influence Clinical Management (A-III)
      • Clinicians Can Consider Influenza Testing for Patients Not at High Risk for Influenza Complications Who Present with Influenza-Like Illness, Pneumonia, or Nonspecific Respiratory Illness (i.e. Cough without Fever) and Who are Likely to Be Discharged Home if the Results Might Influence Antiviral Treatment Decisions or Reduce the Use of Unnecessary Antibiotics, Further Diagnostic Testing, and Time in the Emergency Department, or if the Results Might Influence Antiviral Treatment or Chemoprophylaxis Decisions for High-Risk Household Contacts (C-III)
    • During Low Influenza Activity without Any Link to an Influenza Outbreak
      • Clinicians Can Consider Influenza Testing in Patients with Acute Onset of Respiratory Symptoms with/without Fever (Especially for Immunocompromised and High-Risk Patients) (B-III)
  • Inpatients
    • During Influenza Activity (Defined as the Circulation of Seasonal Influenza A/B Viruses in the Local Community)
      • Clinicians Should Test for Influenza on Admission in All Patients Requiring Hospitalization with Acute Respiratory illness (Including Pneumonia) with/without Fever (A-II)
      • Clinicians Should Test for Influenza on Admission in All Patients with Acute Worsening of Chronic Cardiopulmonary Disease (Asthma, Chronic Obstructive Pulmonary Disease, Coronary Artery Disease, or Heart Failure), as Influenza Can Be Associated with Exacerbation of Underlying Conditions (A-III)
      • Clinicians Should Test for Influenza on Admission in All Patients Who are Immunocompromised or at High Risk of Complications and Present with Acute Onset of Respiratory Symptoms with/without Fever, as the Manifestations of Influenza in Such Patients are Frequently Less Characteristic than in Immunocompetent Individuals (A-III)
      • Clinicians Should Test for Influenza in All Patients Who, While Hospitalized, Develop Acute Onset of Respiratory Symptoms, with/without Fever, or Respiratory Distress, without a Clear Alternative Diagnosis (A-III)
    • During Low Influenza Activity without Any Link to an Influenza Outbreak
      • Clinicians Should Test for Influenza on Admission in All Patients Requiring Hospitalization with Acute Respiratory Illness, with/without Fever, Who Have an Epidemiological Link to a Patient Diagnosed with Influenza, an Influenza Outbreak or Outbreak of Acute Febrile Respiratory Illness of Uncertain Etiology, or Who Recently Traveled from an Area with Known Influenza Activity (A-II)
      • Clinicians Can Consider Testing for Influenza in Patients with Acute, Febrile Respiratory Tract illness, Especially Children and Adults Who are Immunocompromised or at High Risk of Influenza Complications, or if the Results Might Influence Antiviral Treatment or Chemoprophylaxis Decisions for High-Risk Household Contacts (B-III)

Nucleic Acid Testing for Respiratory Pathogens

General Comments

  • Note that in Rhinovirus Infection, Asymptomatic Viral Shedding is Common, Making Multiplex Testing of Unclear Utility (Since No Specific Therapy is Available, Regardless)
    • Positive Rhinovirus PCR Has Been Reported in 6% of Asymptomatic Adults and 35% of Asymptomatic Children at Any Given Point in Time (mSphere, 2018) [MEDLINE] (Pediatrics, 2014) [MEDLINE] (J Infect Dis, 2018) [MEDLINE]

Diagnostic Testing for Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) (see Severe Acute Respiratory Syndrome Coronavirus-2)

  • In Any Patient Presenting with an Acute Respiratory Illness, an Oropharyngeal Swab with Reverse-Transcriptase Polymerase Chain Reaction (RT-PCR) Testing for SARS-CoV-2 is Required for the Purpose of Infection Control

Clinical Efficacy

  • In Patients Hospitalized with Community-Acquired Pneumoniaa, >95% of Patients Received Antibiotics Regardless of Whether They were Found to Be Respiratory Virus Panel Negative or Positive (Am J Infect Control, 2017) [MEDLINE]

BioFire Panel (Biomérieux)

Rapid Microbiologic Diagnostic Platforms (RMDP)

  • LightCycler SeptiFast Test (Roche)
  • Peptide Nucleic Acid Fluorescence in Situ Hybridization (PNA-FISH) (AdvanDx)
  • Matrix-Assisted Laser Desorption-Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry (MS) (VITEK MS; bioMérieux)
  • Polymerase Chain Reaction (PCR) Combined with Electrospray Ionization Mass Spectrometry (PCR/ESI-MS) (Abbott Ibis Biosciences)
  • DNA-Based Microarray Platforms
    • Prove-it Sepsis Assay (Mobidiag)
    • Verigene Gram-Positive Blood Culture Assay (Nanosphere)
  • ID/AST System (Accelerate Diagnostics)
    • Automated Microscopy System, Currently in Development

Recommendations (American Thoracic Society Clinical Practice Guideline for Nucleic Acid-based Testing for Noninfluenza Viral Pathogens in Adults with Suspected Community-Acquired Pneumonia) (Am J Respir Crit Care Med, 2021) [MEDLINE]

  • In Outpatients with Suspected Community-Acquired Pneumonia, Routine Nucleic Acid–Based Testing of Respiratory Samples for Viral Pathogens Other than Influenza (and Presumably SARS-CoV-2) is Not Recommended (Conditional Recommendation, Very Low Quality Evidence)
  • In Inpatients with Suspected Community-Acquired Pneumonia, Nucleic Acid–Based Testing of Respiratory Samples for Viral Pathogens Other than Influenza (and Presumably SARS-CoV-2) is Recommended Only in the Following Groups (Conditional Recommendation, Very Low Quality Evidence)
    • Patients with Severe Community-Acquired Pneumonia, as Defined by the Following
      • General Comments
        • Validated Definition of Severe Community-Acquired Pneumonia Includes Either 1 Major Criterion or ≥3 Minor Criteria
      • Major Criteria
        • Respiratory Failure Requiring Invasive Mechanical Ventilation
        • Septic Shock Requiring Vasopressors
      • Minor Criteria
        • Altered Mental Status
        • Hypotension Requiring Aggressive Intravenous Fluid Resuscitation
        • Hypothermia (Core Temperature <36°C)
        • Leukopenia (WBC <4000 Cells/mm3)
        • Multilobar Infiltrates
        • pO2/FiO2 Ratio ≤250
        • Tachypnea (Respiratory Rate ≥30 Breaths/min)
        • Thrombocytopenia (Platelets <100k Cells/mm3)
        • Uremia (BUN ≥20 mg/dL)
    • Immunocompromised State, as Defined by Any of the Following
      • Active Cancer Therapy
      • Advanced Human Immunodeficiency Virus (HIV) Disease (see Human Immunodeficiency Virus)
      • Chronic Use of Immunosuppressive Medications (Including Systemic Corticosteroids)
      • History of Solid-Organ/Blood Component Transplant
      • Neutropenia (see Neutropenia)

Bronchoscopy (see Bronchoscopy)

Procedures

  • Bronchoalveolar Lavage (BAL)

Recommendations (American Thoracic Society and Infectious Diseases Society of America 2007 Consensus Guidelines on the Management of Community-Acquired Pneumonia in Adults) (Clin Infect Dis, 2007) [MEDLINE]

  • Bronchoscopy May Be Indicated for Patient with Community-Acquired Pneumonia Who is Admitted to the Intensive Care Unit (ICU)

Thoracentesis (see Thoracentesis)

Clinical Classification of Pneumonia (Infectious Diseases Society of America, IDSA/American Thoracic Society, ATS 2016 Clinical Practice Guidelines for the Management of HAP/VAP (Clin Infect Dis, 2016) [MEDLINE]

Pneumonia (see Pneumonia)

Community-Acquired Pneumonia (CAP)

Healthcare-Associated Pneumonia (HCAP)

Hospital-Acquired Pneumonia (HAP) (see Hospital-Acquired Pneumonia and Ventilator-Associated Pneumonia)

Ventilator-Associated Tracheobronchitis

Ventilator-Associated Pneumonia (VAP) (see Hospital-Acquired Pneumonia and Ventilator-Associated Pneumonia)

Clinical-Pneumonia Scoring

Clinical Pneumonia Scoring Systems

Clinical Data

Clinical Manifestations

Pulmonary Manifestations

Clinical Efficacy of Symptoms and Signs in the Diagnosis of Community-Acquired Pneumonia (CAP)

  • Army Medical Center Emergency Department Study of the Diehr Rule for the Prediction of Pneumonia in Patients Presenting with Acute Cough (J Chronic Dis, 1984) [MEDLINE]: n = 1,819
    • Pneumonia was Radiographically Diagnosed in 2.6% of the Patients
    • Clinical Decision Rule (Developed in 1,00 of Patients, Validated in 483 Patients)
      • Rhinorrhea: -2 point
      • Sore Throat: -1 point
      • Night Sweats/Myalgias/All-Day Sputum Production: 1 point
      • Respiratory Rate >25 breaths/min: 2 points
      • T >100 °F (37.8 °C)
    • Interpretation of Score
      • Score of -2 to -3 Points: likelihood of pneumonia was<1%
      • Score of 3-6 Points: likelihood of pneumonia was 27%
  • Emergency Department Study of Gennis Rule for the Diagnosis of Pneumonia (J Emerg Med, 1989) [MEDLINE]: n= 308
    • 38% of the Patients Had Radiographic Pneumonia
    • Symptoms
      • No Single Symptom or Sign was Reliably Predictive of Pneumonia
      • Cough was the Most Common Symptom (Present in 86% of Cases, But was Equally Common in Patients without Pneumonia)
      • Fever was Absent in 31% of Patients with Pneumonia
      • Abnormal Lung Exam (Rales, Rhonchi, Decreased Breath Sounds, Wheezes, Altered Fremitus, Egophony, Dullness to Percussion) were Found in <50% of the Patients with Pneumonia and 22% of Patients with a Completely Normal Lung Exam Had Pneumonia
    • Rule Criteria for Obtaining a Chest X-Ray, Based on Presence of At Least One of the Following (97% Sensitivity)
      • Temperature >100 °F (37.8 °C)
      • Heart Rate >100 beats/min
      • Respiratory Rate >20 breaths/min
  • Emergency Department Prospective Observational Study of Singal Rule for the Diagnosis of Pneumonia (Ann Emerg Med, 1989) [MEDLINE]: n = 255 adults
    • 15.6% of Adult Patients Had Radiographic Pneumonia
    • Univariate Predictors of Pneumonia were Fever, Cough, Crackles
      • In Absence of Fever, Cough, and Crackles, Incidence of Pneumonia was Only 4.3%
  • Emergency Department Study of the Heckerling Rule for the Diagnosis of Pneumonia (Ann Intern Med, 1990) [MEDLINE]: n= 1,436 (3 different emergency departments)
    • Rule was Developed in 1,134 Patients and Validated in 302 Patients
    • Rule Criteria for Obtaining a Chest X-Ray (from Stepwise Logistic Regression Model; p <0.001)
      • Temperature >100 °F (37.8 °C): 1 point
      • Heart Rate >100 beats/min: 1 point
      • Crackles: 1 point
      • Decreased Breath Sounds (Locally): 1 point
      • Absence of Asthma: 1 point
    • Interpretation of Score (Pre-Test Probability was 5% in Primary Care and 15% in Emergency Department)
      • Score 0
        • Post-Test Probability of Pneumonia (Primary Care): 1%
        • Post-Test Probability of Pneumonia (Emergency Department): 2%
        • Likelihood Ratio: 0.12
      • Score 1
        • Post-Test Probability of Pneumonia (Primary Care): 1%
        • Post-Test Probability of Pneumonia (Emergency Department): 3%
        • Likelihood Ratio: 0.2
      • Score 2
        • Post-Test Probability of Pneumonia (Primary Care): 4%
        • Post-Test Probability of Pneumonia (Emergency Department): 11%
        • Likelihood Ratio: 0.7
      • Score 3
        • Post-Test Probability of Pneumonia (Primary Care): 8%
        • Post-Test Probability of Pneumonia (Emergency Department): 22%
        • Likelihood Ratio: 1.6
      • Score 4
        • Post-Test Probability of Pneumonia (Primary Care): 27%
        • Post-Test Probability of Pneumonia (Emergency Department): 56%
        • Likelihood Ratio: 7.2
      • Score 5
        • Post-Test Probability of Pneumonia (Primary Care): 47%
        • Post-Test Probability of Pneumonia (Emergency Department): 75%
        • Likelihood Ratio: 17
    • Rule Had a Receiver Operating Characteristic (ROC) Area 0.82
      • In the Validation Sets, the Rule Discriminated Pneumonia and Non-Pneumonia with ROC Areas of 0.82 and 0.76 (After Adjusting for Differences in Disease Prevalence)
  • Comparative Prospective Study of Diehr/Gennis/Heckerling/Singal Rules with Physician Judgement for the Diagnosis of Pneumonia in Emergency Department and Outpatient Settings (Ann Emerg Med, 1991) [MEDLINE]: n = 290
    • All Patients Had an Acute Cough and Fever, Hemoptysis, or Sputum Production

Abnormal Pulmonary Exam Findings

  • Findings Consistent with Consolidation (Alveolar Filling Process)
    • Bronchial Breath Sounds [LINK]
      • Due to Improved Transmission of Bronchial Breath Sounds Through the Consolidated Lung (Which Has Higher Density)
    • Crackles [LINK]
    • Dulness to Percussion [LINK]
      • Due to Increased Density of Consolidated Lung (Which Has Higher Density)
    • Increased Tactile Fremitus [LINK]
      • Due to Sound Traveling 4x Faster Through Water (Higher Density) than Through Air (Lower Density)
    • Increased Whispered Pectoriloquy [LINK]
      • Due to Sound Traveling 4x Faster Through Water (Higher Density) than Through Air (Lower Density)
    • Egophony (E -> A Changes) [LINK]
      • Due to Low-Pass Frequency Filter Effect (Stiff Barrier Attenuates High Frequencies and Allows Low Frequencies to Pass Through)
  • XXXX
    • XXXX

Cough with Sputum Production (see Cough)

  • XXXX

Dyspnea (see Dyspnea)

  • XXXX

Hypoxemia (see Hypoxemia)

  • XXXX

Parapneumonic Effusion (see Pleural Effusion-Parapneumonic)

  • Presence of Pleural Effusion at Emergency Department Presentation with Pneumonia Predicts an Increasing Likelihood of Being Admitted, Longer Hospital Stay, and Increased 30-Day Mortality Rate (Chest, 2016) [MEDLINE]

Pleuritic Chest Pain (see Chest Pain)

  • XXXX

Other Manifestations

Prevention of Community-Acquired Pneumonia (CAP)

Vaccination

Smoking Cessation (see Tobacco)

Treatment of Community-Acquired Pneumonia (CAP)

Site of Care

Clinical Data-Hospital Admission

  • The Decision to Admit a Patient for Community-Acquired Pneumonia is the Most Costly Issue in the Management of Community-Acquired Pneumonia
    • Inpatient Care for Pneumonia is 25x as Expensive as Outpatient Care (Clin Ther, 1998) [MEDLINE]
    • Inpatient Care for Pneumonia Consumes the Majority of the Estimated $8.4-10 Billion Spent Annually on Pneumonia Treatment
  • CAP Patients Treated as Outpatients are Able to Resume Normal Activity Sooner than Those Who are Hospitalized
    • Approximately 74% of CAP Patients Prefer Outpatient Treatment (Arch Intern Med, 1996) [MEDLINE]
  • Hospitalization Increases the Risk of Venous Thromboembolism and Superinfection with More Virulent or Resistant Organisms (Arch Intern Med, 2004) [MEDLINE]

Clinical Data-Intensive Care Unit Admission

  • Systematic Review and Meta-Analysis of Criteria to Predict Intensive Care Unit Admission in Community-Acquired Pneumonia
    • Without the Major Criteria, a Threshold ≥3 Community-Acquired Pneumonia Minor Criteria (Below) Had a Pooled Sensitivity of 56% and Specificity of 91% for Predicting Intensive Care Unit Admission (Intensive Care Med, 2011) [MEDLINE]
  • Study of Association Between Intensive Care Unit Admission and Mortality in Patients with Pneumonia (JAMA, 2015) [MEDLINE]
    • Among Medicare Beneficiaries Hospitalized with Pneumonia, Intensive Care Unit Admission of Patients for Whom the Decision Appeared to Be Discretionary was Associated with Improved Survival and No Significant Difference in Costs

Recommendations (American Thoracic Society and Infectious Diseases Society of America 2019 Clinical Practice Guidelines for the Diagnosis and Treatment of Adults with Community-Acquired Pneumonia) (Am J Respir Crit Care Med, 2019) [MEDLINE]

  • In Addition to Clinical Judgement, it is Recommended to Use a Validated Clinical Prediction Rule to Determine the Need for Hospitalization in Adults Diagnosed with Community-Acquired Pneumonia (Conditional Recommendation, Low Quality of Evidence)
    • Pneumonia Severity Index (PSI) is Preferred Over the CURB-65 (Tool Based on Confusion, Urea Level, Respiratory Rate, Blood Pressure, and Age >65) (Strong Recommendation, Moderate Quality of Evidence)
  • In Patient with Hypotension Requiring Vasopressors or Respiratory Failure Requiring Mechanical Ventilation, Intensive Care Unit Admission is Recommended (Strong Recommendation, Low Quality of Evidence)
  • In a Patient Not Requiring Vasopressors or Mechanical Ventilation, the Community-Acquired Pneumonia Minor Severity Criteria Below Combined with Clinical Judgment are Recommended to Guide the Need for Higher Levels of Treatment Intensity (Conditional Recommendation, Low Quality of Evidence)
    • Criteria for Severe Community-Acquired Pneumonia (Infectious Diseases Society of America, IDSA/American Thoracic Society, ATS 2007 Consensus Guidelines for the Management of CAP) (Clin Infect Dis, 2007) [MEDLINE]
      • General Comments
        • Validated Definition of Severe Community-Acquired Pneumonia Includes Either 1 Major Criterion or ≥3 Minor Criteria
      • Major Criteria
        • Respiratory Failure Requiring Invasive Mechanical Ventilation
        • Septic Shock Requiring Vasopressors
      • Minor Criteria
        • Altered Mental Status
        • Hypotension Requiring Aggressive Intravenous Fluid Resuscitation
        • Hypothermia (Core Temperature <36 °C)
        • Leukopenia (WBC <4000 Cells/mm3)
        • Multilobar Infiltrates
        • pO2/FiO2 Ratio ≤250
        • Tachypnea (Respiratory Rate ≥30 Breaths/min)
        • Thrombocytopenia (Platelets <100k Cells/mm3)
        • Uremia (BUN ≥20 mg/dL)

Antibiotics

Clinical Efficacy-Choice of Empiric Antibiotic

  • VA Retrospective Cohort Study Examining the Impact of Azithromycin on Mortality and Cardiovascular Events in Older Patients Hospitalized with Pneumonia (JAMA, 2014) MEDLINE]: n = 73,690 patients (from 118 hospitals)
    • Azithromycin Decreased the 90-Day Mortality Rate, as Compared to Other Antibiotics
    • Azithromycin Also Demonstrated a Smaller Increased Risk of Myocardial Infarction, But No Difference in Arrhythmias or Congestive Heart Failure
  • CAP-START Trial-Antibiotic Choice in Non-ICU Community-Acquired Pneumonia (NEJM, 2015) [MEDLINE]
    • Empiric Treatment with β-Lactam Monotherapy was Non-Inferior to β-Lactam/Macrolide Combination or Fluoroquinolones with Respect to the 90-Day Mortality Rate
  • VA Retrospective Multicenter Cohort Study of the Impact of Empiric Anti-MRSA Antibiotic Therapy (within the First Day of Hospitalization) in Patients Hospitalized for Community-Acquired Pneumonia (CAP) (JAMA Intern Med, 2020) [MEDLINE]: n = 88, 605 hospitalized patients (from 2008-2013)
    • VA Study: population consisted of predominantly males (86 ,851 out of 88,605), median age 70 years (interquartile range: 62-81 y/o)
    • Subgroup Analysis was Performed in Patients with Initial Intensive Care Unit Admission, MRSA Risk Factors, Positive Results of a MRSA Surveillance Test, and/or Positive Results of an MRSA Admission Culture
    • Empirical Anti-MRSA Therapy Plus Standard Therapy was Significantly Associated with an Increased Adjusted Risk of Death (Adjusted Risk Ratio 1.4; 95% CI: 1.3-1.5), Kidney Injury (Adjusted Risk Ratio 1.4; 95% CI: 1.3-1.5), and Secondary Clostridium Difficile Infections (Adjusted Risk Ratio 1.6; 95% CI: 1.3-1.9), Vancomycin-Resistant Enterococcus Species Infections (Adjusted Risk Ratio 1.6; 95% CI: 1.0-2.3), and Secondary Gram-Negative Rod Infections (Adjusted Risk Ratio 1.5; 95% CI: 1.2-1.8)
    • Empirical Anti-MRSA Antibiotic Therapy was Not Associated with Decreased 30-Day Mortality for Any Group of Patients Hospitalized for Pneumonia

Recommendations-Choice of Empiric Antibiotic Therapy (American Thoracic Society and Infectious Diseases Society of America 2019 Clinical Practice Guidelines for the Diagnosis and Treatment of Adults with Community-Acquired Pneumonia) (Am J Respir Crit Care Med, 2019) [MEDLINE]

  • Outpatient Adult without Comorbidities or Risk Factors for Methicillin-Resistant Staphylococcus Aureus (MRSA) or Pseudomonas Aeruginosa
    • Amoxicillin (see Amoxicillin): 1 g PO TID (Strong Recommendation, Moderate Quality of Evidence)
    • Doxycycline (see Doxycycline): 100 mg PO BID (Conditional Recommendation, Low Quality of Evidence)
    • Macrolide (Azithromycin, Clarithromycin) (see Macrolides) (Conditional Recommendation, Moderate Quality of Evidence)
      • Use Macrolides Only in Regions with Streptococcus Pneumoniae Resistance (MIC ≥16 μg/mL) to Macrolides <25%
      • Azithromycin (see Azithromycin): 500 mg PO on first day, then 250 mg PO qday
      • Clarithromycin (see Clarithromycin): 500 mg PO BID (or extended-release 1000 mg PO qday)
  • Outpatient Adult with Comorbidities (Chronic Heart/Lung/Liver/Renal Disease, Diabetes Mellitus, Alcoholism, Malignancy, Asplenia)
    • Monotherapy (Strong Recommendation, Moderate Quality of Evidence)
      • Respiratory Fluoroquinolone
    • Combination Therapy (Strong Recommendation, Moderate Quality of Evidence for Combination Therapy with Macrolides; Conditional Recommendation, Low Quality of Evidence for Combination Therapy with Doxycycline)
  • Outpatient Adult with Risk Factors for Methicillin-Resistant Staphylococcus Aureus (MRSA) or Pseudomonas Aeruginosa (Prior Respiratory Isolation of Methicillin-Resistant Staphylococcus Aureus, Prior Respiratory Isolation of Pseudomonas Aeruginosa, or Recent Hospitalization with Intravenous Antibiotics in the Last 90 Days
    • Same as for Outpatient with Co-Morbidities (Chronic Heart/Lung/Liver/Renal Disease, Diabetes Mellitus, Alcoholism, Malignancy, Asplenia) with Added Coverage for Methicillin-Resistant Staphylococcus Aureus (MRSA) or Pseudomonas Aeruginosa
      • However, Patients with Methicillin-Resistant Staphylococcus Aureus (MRSA) or Pseudomonas Aeruginosa are Uncommonly Managed in the Outpatient Setting
  • Inpatient Adult with Suspected Aspiration Pneumonia
    • Routine Addition of Anaerobic Antibiotic Coverage for Suspected Aspiration Pneumonia is Not Recommended, Unless Lung Abscess or Empyema is Suspected (Conditional Recommendation, Very Low Quality of Evidence)
  • Inpatient Adult with Non-Severe Community-Acquired Pneumonia and Absence of Risk Factors for Methicillin-Resistant Staphylococcus Aureus (MRSA) or Pseudomonas Aeruginosa
    • Monotherapy (Strong Recommendation, High Quality of Evidence)
      • Respiratory Fluoroquinolone
    • Combination Therapy (Strong Recommendation, High Quality of Evidence for Combination Therapy with Macrolide; Conditional Recommendation, Low Quality of Evidence for Combination Therapy with Doxycycline)
  • Inpatient Adult with Non-Severe Community-Acquired Pneumonia and Prior Respiratory Isolation of Methicillin-Resistant Staphylococcus Aureus (MRSA)
    • Background
      • The Use of the Prior Term, Healthcare-Associated Pneumonia (HCAP), to Guide Selection of Extended Antibiotic Coverage in Adults with Community-Acquired Pneumonia Should Be Abandoned (Strong Recommendation, Moderate Quality of Evidence)
      • Prior Identification of Methicillin-Resistant Staphylococcus Aureus (MRSA) in the Respiratory Tract within the Prior Year Predicts a Very High Risk of This Pathogen Being Identified in Patients Presenting with Community-Acquired Pneumonia
    • Monotherapy with Respiratory Fluoroquinolone or Combination β-Lactam and Macrolide (or Doxycycline): see above
    • Add Methicillin-Resistant Staphylococcus Aureus Coverage and Obtain Cultures/Nasal PCR to Allow Deescalation or Confirm Need for Continued Methicillin-Resistant Staphylococcus Aureus (MRSA) Therapy
      • Linezolid (see Linezolid): 600 mg PO/IV q12hrs
      • Vancomycin (see Vancomycin): 15 mg/kg IV q12hrs (adjust based on levels)
  • Inpatient Adult with Non-Severe Community-Acquired Pneumonia and Recent Hospitalization with Intravenous Antibiotics and Locally Validated Risk Factors for Methicillin-Resistant Staphylococcus Aureus (i.e Whether Methicillin-Resistant Staphylococcus Aureus is Prevalent in Patients with Community-Acquired Pneumonia and What Risk Factors for Infection are at a Local Hospital/Catchment Area Level) (Strong Recommendation, Moderate Quality of Evidence)
    • Background
      • The Use of the Prior Term, Healthcare-Associated Pneumonia (HCAP), to Guide Selection of Extended Antibiotic Coverage in Adults with Community-Acquired Pneumonia Should Be Abandoned (Strong Recommendation, Moderate Quality of Evidence)
      • There are No Validated Scoring Systems to Identify Patients with Methicillin-Resistant Staphylococcus Aureus (MRSA) or Pseudomonas Aeruginosa with Sufficiently High Positive Predictive Value to Determine the Need for Empiric Extended-Spectrum Antibiotic Treatment (Due to Varying Prevalence of These Organisms in Different Populations and Lack of Benefit in Terms of Patient Outcome or Reduction in the Use of Broad-Spectrum Antibiotics)
        • However, as Noted Above (See Diagnostic), a Nasal Methicillin-Resistant Staphylococcus Aureus Culture Has a High Negative Predictive Value (i.e. Treatment for Methicillin-Resistant Staphylococcus Aureus (MRSA) Can Generally Be Withheld When the Nasal Methicillin-Resistant Staphylococcus Aureus (MRSA) is Negative, Especially in Non-Severe Community-Acquired Pneumonia)
      • If Clinicians are Currently Covering Empirically for Methicillin-Resistant Staphylococcus Aureus (MRSA) in Adults with Community-Acquired Pneumonia Based on Published Risk Factors, But Do Not Have Local Etiologic Data, Continuing Empiric Coverage While Obtaining Culture Data to Justify Continued Treatment is Recommended (Strong Recommendation, Low Quality of Evidence)
    • Monotherapy with Respiratory Fluoroquinolone or Combination β-Lactam and Macrolide (or Doxycycline): see above
    • Obtain Cultures, But Withhold Methicillin-Resistant Staphylococcus Aureus Coverage Unless Culture Results are Positive
      • If Methicillin-Resistant Staphylococcus Aureus Rapid Nasal PCR Testing is Negative, Withhold Additional Empiric Therapy Against Methicillin-Resistant Staphylococcus Aureus
      • If Methicillin-Resistant Staphylococcus Aureus Rapid Nasal PCR Testing is Positive, Add Methicillin-Resistant Staphylococcus Aureus Coverage and Obtain Cultures
  • Inpatient Adult with Non-Severe Community-Acquired Pneumonia and Prior Respiratory Isolation of Pseudomonas Aeruginosa
    • Background
      • The Use of the Prior Term, Healthcare-Associated Pneumonia (HCAP), to Guide Selection of Extended Antibiotic Coverage in Adults with Community-Acquired Pneumonia Should Be Abandoned (Strong Recommendation, Moderate Quality of Evidence)
      • Prior Identification of Pseudomonas Aeruginosa in the Respiratory Tract within the Prior Year Predicts a Very High Risk of This Pathogen Being Identified in Patients Presenting with Community-Acquired Pneumonia
    • Monotherapy with Respiratory Fluoroquinolone or Combination β-Lactam and Macrolide (or Doxycycline): see above
    • Add Coverage for Pseudomonas Aeruginosa and Obtain Cultures to Allow Deescalation or Confirmation of Need for Continued Pseudomonas Aeruginosa Therapy: does not include coverage for extended-spectrum β-lactamase–producing Enterobacteriaceae (which should be considered only on the basis of patient or local microbiological data)
  • Inpatient Adult with Non-Severe Community-Acquired Pneumonia and Recent Hospitalization with Intravenous Antibiotics and Locally Validated Risk Factors for Pseudomonas Aeruginosa (i.e. Whether Pseudomonas Aeruginosa is Prevalent in Patients with Community-Acquired Pneumonia and What Risk Factors for Infection are Present at a Local Hospital/Catchment Area Level) (Strong Recommendation, Moderate Quality of Evidence)
    • Background
      • The Use of the Prior Term, Healthcare-Associated Pneumonia (HCAP), to Guide Selection of Extended Antibiotic Coverage in Adults with Community-Acquired Pneumonia Should Be Abandoned (Strong Recommendation, Moderate Quality of Evidence)
      • There are No Validated Scoring Systems to Identify Patients with Methicillin-Resistant Staphylococcus Aureus (MRSA) or Pseudomonas Aeruginosa with Sufficiently High Positive Predictive Value to Determine the Need for Empiric Extended-Spectrum Antibiotic Treatment (Due to Varying Prevalence of These Organisms in Different Populations and Lack of Benefit in Terms of Patient Outcome or Reduction in the Use of Broad-Spectrum Antibiotics)
      • If Clinicians are Currently Covering Empirically for Pseudomonas Aeruginosa in Adults with Community-Acquired Pneumonia Based on Published Risk Factors, But Do Not Have Local Etiologic Data, Continuing Empiric Coverage While Obtaining Culture Data to Justify Continued Treatment is Recommended (Strong Recommendation, Low Quality of Evidence)
    • Monotherapy with Respiratory Fluoroquinolone or Combination β-Lactam and Macrolide (or Doxycycline): see above
    • Obtain Cultures, But Initiate Pseudomonas Aeruginosa Coverage Only if Culture Results are Positive
  • Inpatient Adult with Severe Community-Acquired Pneumonia and Absence of Risk Factors for Methicillin-Resistant Staphylococcus Aureus (MRSA) or Pseudomonas Aeruginosa
    • Combination Therapy (Strong Recommendation, Moderate Quality of Evidence for Combination Therapy with Macrolide; Strong Recommendation, Low Quality of Evidence for Combination Therapy with Respiratory Fluoroquinolone)
  • Inpatient Adult with Severe Community-Acquired Pneumonia and with Prior Respiratory Isolation of Methicillin-Resistant Staphylococcus Aureus (MRSA) or Recent Hospitalization with Intravenous Antibiotics and Locally Validated Risk Factors for Methicillin-Resistant Staphylococcus Aureus (MRSA) Therapy (i.e. Whether Methicillin-Resistant Staphylococcus Aureus is Prevalent in Patients with Community-Acquired Pneumonia and What Risk Factors for Infection are Present at a Local Hospital/Catchment Area Level) (Strong Recommendation, Moderate Quality of Evidence)
    • Background
      • The Use of the Prior Term, Healthcare-Associated Pneumonia (HCAP), to Guide Selection of Extended Antibiotic Coverage in Adults with Community-Acquired Pneumonia Should Be Abandoned (Strong Recommendation, Moderate Quality of Evidence)
      • Prior Identification of Methicillin-Resistant Staphylococcus Aureus (MRSA) in the Respiratory Tract within the Prior Year Predicts a Very High Risk of This Pathogen Being Identified in Patients Presenting with Community-Acquired Pneumonia
      • There are No Validated Scoring Systems to Identify Patients with Methicillin-Resistant Staphylococcus Aureus (MRSA) or Pseudomonas Aeruginosa with Sufficiently High Positive Predictive Value to Determine the Need for Empiric Extended-Spectrum Antibiotic Treatment (Due to Varying Prevalence of These Organisms in Different Populations and Lack of Benefit in Terms of Patient Outcome or Reduction in the Use of Broad-Spectrum Antibiotics)
        • However, as Noted Above (See Diagnostic), a Nasal Methicillin-Resistant Staphylococcus Aureus (MRSA) Culture Has a High Negative Predictive Value (i.e. Treatment for Methicillin-Resistant Staphylococcus Aureus Can Generally Be Withheld When the Nasal Methicillin-Resistant Staphylococcus Aureus (MRSA) is Negative, Especially in Non-Severe Community-Acquired Pneumonia)
      • If Clinicians are Currently Covering Empirically for Methicillin-Resistant Staphylococcus Aureus (MRSA) in Adults with Community-Acquired Pneumonia Based on Published Risk Factors, But Do Not Have Local Etiologic Data, Continuing Empiric Coverage While Obtaining Culture Data to Justify Continued Treatment is Recommended (Strong Recommendation, Low Quality of Evidence)
    • Combination β-Lactam and Macrolide (or Respiratory Fluoroquinolone): see above
    • Add Methicillin-Resistant Staphylococcus Aureus (MRSA) Coverage and Obtain Cultures/Nasal PCR to Allow Deescalation or Confirmation of Need for Continued Methicillin-Resistant Staphylococcus Aureus MRSA) Therapy
      • Linezolid (see Linezolid): 600 mg PO/IV q12hrs
      • Vancomycin (see Vancomycin): 15 mg/kg IV q12hrs (adjust based on levels)
  • Inpatient Adult with Severe Community-Acquired Pneumonia and Prior Respiratory Isolation of Pseudomonas Aeruginosa or Recent Hospitalization with Intravenous Antibiotics and Locally Validated Risk Factors for Pseudomonas Aeruginosa (i.e. Whether Pseudomonas Aeruginosa is Prevalent in Patients with Community-Acquired Pneumonia and What Risk Factors for Infection are Present at a Local Hospital/Catchment Area Level) (Strong Recommendation, Moderate Quality of Evidence)
    • Background
      • The Use of the Prior Term, Healthcare-Associated Pneumonia (HCAP), to Guide Selection of Extended Antibiotic Coverage in Adults with Community-Acquired Pneumonia Should Be Abandoned (Strong Recommendation, Moderate Quality of Evidence)
      • Prior Identification of Pseudomonas Aeruginosa in the Respiratory Tract within the Prior Year Predicts a Very High Risk of This Pathogen Being Identified in Patients Presenting with Community-Acquired Pneumonia
      • There are No Validated Scoring Systems to Identify Patients with Methicillin-Resistant Staphylococcus Aureus (MRSA) or Pseudomonas Aeruginosa with Sufficiently High Positive Predictive Value to Determine the Need for Empiric Extended-Spectrum Antibiotic Treatment (Due to Varying Prevalence of These Organisms in Different Populations and Lack of Benefit in Terms of Patient Outcome or Reduction in the Use of Broad-Spectrum Antibiotics)
      • If Clinicians are Currently Covering Empirically for Pseudomonas Aeruginosa in Adults with Community-Acquired Pneumonia Based on Published Risk Factors, But Do Not Have Local Etiologic Data, Continuing Empiric Coverage While Obtaining Culture Data to Justify Continued Treatment is Recommended (Strong Recommendation, Low Quality of Evidence)
    • Combination β-Lactam and Macrolide (or Respiratory Fluoroquinolone): see above
    • Add Pseudomonas Aeruginosa Coverage and Obtain Cultures

Recommendations-Choice of Targeted Antibiotic Against a Specific Pathogen (Infectious Diseases Society of America, IDSA/American Thoracic Society, ATS 2007 Consensus Guidelines for the Management of CAP) (Clin Infect Dis, 2007) [MEDLINE]

Time to First Antibiotic Dose

  • Clinical Efficacy
    • Retrospective Medicare Study of Timing of Antibiotic Administration in Patients Hospitalized with CAP (Arch Intern Med, 2004) [MEDLINE]
      • Early Antibiotic Therapy Within 4 hrs is Associated with Decreased In-Hospital Mortality Rate, 30-Day Mortality Rate, and Hospital Length of Stay
  • Recommendations (Infectious Diseases Society of America, IDSA/American Thoracic Society, ATS 2007 Consensus Guidelines for the Management of CAP) (Clin Infect Dis, 2007) [MEDLINE]
    • For Patients Admitted Via the Emergency Department, First Antibiotic Dose Should Be Administered in the Emergency Department (Moderate Recommendation, Level III Evidence): no specific length of time was specified

Switch from Intravenous to Oral Antibiotic Therapy

  • Recommendations (Infectious Diseases Society of America, IDSA/American Thoracic Society, ATS 2007 Consensus Guidelines for the Management of CAP) (Clin Infect Dis, 2007) [MEDLINE]
    • Patients Should Be Switched from Intravenous to Oral Antibiotic Therapy When They are Hemodynamically Stable and Improving Clinically, Able to Ingest Medications, and have a Normally Functioning Gastrointestinal Tract (Strong Recommendation, Level II Evidence)
    • Patients Should Be Discharged as Soon as they are Clinically Stable, Have No Other Active Medical Problems, and Have a Safe Environment for Continued Care (Moderate Recommendation, Level II Evidence): inpatient observation while receiving oral therapy is not necessary

Duration of Antibiotic Therapy

  • Clinical Efficacy
    • De-Escalation of Antibiotics (Curr Opin Pulm Med, 2006) [MEDLINE]
      • De-Escalation is an Effective Strategy to Limit Antibiotic Exposure During the Course of Pneumonia Treatment
    • Spanish Multicenter Randomized Trial of Shortened Antibiotic Course in Community-Acquired Pneumonia (JAMA Intern Med, 2016) [MEDLINE]: n = 312
      • Infectious Diseases Society of America (IDSA)/American Thoracic Society (ATS) Guideline for Shortened Antibiotic Course Based on Clinical Stability was Safely Implemented in Hospitalized Patients with CAP: patients in shortened course intervention group were treated for a minimum of 5 days and antibiotics were stopped if body temperature was <37.8 degrees C for 48 hrs and they had ≤1 CAP-associated sign of clinical instability (temperature ≥37.8 degrees C, heart rate ≥100 bpm, respiratory rate ≥24 breaths/min, systolic blood pressure ≤90 mm Hg, room air SaO2 ≤90% or pO2 ≤60, inability to maintain oral intake, or altered mental status)
    • Cochrane Database Systematic Review and Meta-Analysis of Using Serum Procalcitonin to Start or Stop Antibiotics in Acute Respiratory Tract Infection (Cochrane Database Syst Rev, 2017) [MEDLINE]
      • Use of Serum Procalcitonin to Guide Initiation and Duration of Antibiotics Results in Lower Risks of Mortality, Lower Antibiotic Consumption, and Lower Risk of Antibiotic-Associated Adverse Effects
      • Results were Similar for Different Clinical Settings and Types of Acute Respiratory Tract Infections
      • Future Research is Required to Confirm the Results in Immunocompromised Patients and Patients with Non-Respiratory Infections
  • Recommendations (Infectious Diseases Society of America, IDSA/American Thoracic Society, ATS 2007 Consensus Guidelines for the Management of CAP) (Clin Infect Dis, 2007) [MEDLINE]
    • Treatment for a Minimum of 5 Days is Recommended (Moderate Recommendation, Level I Evidence)
    • Patient Should Have for Temperature <37.8 degrees C for 48-72 hrs and Have ≤1 CAP-Associated Sign of Clinical Instability (Temperature ≥37.8 degrees C, Heart Rate ≥100 bpm, Respiratory Rate ≥24 breaths/min, Systolic Blood Pressure ≤90 mm Hg, Room Air SaO2 ≤90% or pO2 ≤60, Inability to Maintain Oral Intake, or Altered Mental Status) Prior to Antibiotic Discontinuation (Moderate Recommendation, Level II Evidence)
    • Longer Duration of Antibiotic Therapy May Be Required if Initial Antibiotic Therapy was Not Active Against the Identified Pathogen or if Pneumonia is Complicated by Extrapulmonary Infection (Meningitis, Endocarditis, etc) (Weak Recommendation, Level III Evidence)
  • Clinical Guidelines for Short-Course Antibiotics in Common Infections (Annals of Internal Medicine, 2021) [MEDLINE]
    • Clinicians Should Prescribe Antibiotics for Community-Acquired Pneumonia for a Minimum of 5 Days
    • Extension of Therapy After 5 Days of Antibiotics Should Be Guided by Validated Measures of Clinical Stability (Including Resolution of Vital Sign Abnormalities, Ability to Eat, and Normal Mentation)
  • Recommendations-Duration of Antibiotic Therapy (American Thoracic Society and Infectious Diseases Society of America 2019 Clinical Practice Guidelines for the Diagnosis and Treatment of Adults with Community-Acquired Pneumonia) (Am J Respir Crit Care Med, 2019) [MEDLINE]
    • Duration of Therapy Should Be Guided by Validated Measures of Clinical Stability (Resolution of Heart Rate/Respiratory Rate/Blood Pressure/Oxygen Saturation/Temperature Abnormalities), Ability to Eat, and Normal Mentation (Strong Recommendation, Moderate Quality of Evidence)
    • Antibiotic Therapy Should Be Continued Until the Patient Achieves Stability and For ≥5 Days (Strong Recommendation, Moderate Quality of Evidence)
      • Longer Antibiotic Courses are Recommended for the Following
        • Pneumonia Complicated by Endocarditis/Meningitis/Other Deep-Seated Infection
        • Infection with Less Common Pathogens Not Covered in These Guidelines (i.e. Burkholderia Pseudomallei, Mycobacterium Tuberculosis, Endemic Fungi, etc)
      • Duration of Therapy for Community-Required Pneumonia Due to Methicillin-Resistant Staphylococcus Aureus (MRSA) of Pseudomonas Aeruginosa Should Be 7 Days (in Agreement with the Hospital-Acquired Pneumonia and Ventilator-Associated Pneumonia Guidelines)

Reasons for Failure to Respond to Antibiotic Therapy (Infectious Diseases Society of America, IDSA/American Thoracic Society, ATS 2007 Consensus Guidelines for the Management of CAP) (Clin Infect Dis, 2007) [MEDLINE]

  • General Comments
    • Approximately 45% of Patients with Community-Acquired Pneumonia Who Ultimately Require ICU Admission are Initially Admitted to a Non-ICU Setting and are Transferred Due to Clinical Deterioration (Thorax, 2004) [MEDLINE]
  • Etiologies of Failure to Improve
    • Early (<72 hrs of Treatment)
      • Normal Response
    • Delayed
      • Complication of Pneumonia: such as Cryptogenic Organizing Pneumonia (COP) (see Cryptogenic Organizing Pneumonia)
      • Drug Fever
      • Hospital-Acquired Superinfection (Pulmonary or Extrapulmonary)
      • Misdiagnosis: patient may alternately have acute pulmonary embolism (PE), congestive heart failure (CHF), vasculitis (due to SLE), cryptogenic organizing pneumonia (COP), etc
      • Parapneumonic Effusion/Empyema
      • Resistant Organism
      • Uncovered Pathogen
  • Etiologies of Clinical Deterioration or Progression
    • Early (<72 hrs of Treatment)
      • Extrapulmonary Focus of Infection: such as meningitis, endocarditis, arthritis, etc
      • Misdiagnosis: patient may alternately have acute pulmonary embolism (PE), congestive heart failure (CHF), vasculitis (due to SLE), cryptogenic organizing pneumonia (COP), etc
      • Parapneumonic Effusion/Empyema
      • Resistant Organism
      • Severity of Illness at Presentation
      • Uncovered Pathogen
    • Delayed
      • Exacerbation of Comorbid Illness: such as COPD exacerbation, etc
      • Hospital-Acquired Superinfection (Pulmonary or Extrapulmonary)
      • Intercurrent Complicating Illness: such as myocardial infarction, acute pulmonary embolism, renal failure, line infection, etc

Risk of Treatment Failure in Community-Acquired Pneumonia (CAP) (Thorax, 2004) [MEDLINE]

Treatment of Concomitant Influenza and Community-Acquired Pneumonia (see Influenza Virus)

Recommendations-Choice of Empiric Antibiotic Therapy (American Thoracic Society and Infectious Diseases Society of America 2019 Clinical Practice Guidelines for the Diagnosis and Treatment of Adults with Community-Acquired Pneumonia) (Am J Respir Crit Care Med, 2019) [MEDLINE]

  • Outpatient Setting
    • In Adults with Influenza and Community-Acquired Pneumonia, Anti-Influenza Treatment (Such as Oseltamivir) is Suggested, Independent of the Duration of Illness Before Diagnosis (Conditional Recommendation, Low Quality of Evidence)
    • In Adults with Concomitant Influenza and Clinical and Radiographic Evidence of Community-Acquired Pneumonia, Standard Antibacterial Therapy is Recommended to Treat the Community-Acquired Pneumonia in Both Outpatient/Inpatient Settings (Strong Recommendation, Low Quality of Evidence)
  • Inpatient Setting
    • In Adults with Influenza and Community-Acquired Pneumonia, Antiinfluenza Treatment (Such as Oseltamivir) is Recommended, Independent of the Duration of Illness Before Diagnosis (Strong Recommendation, Moderate Quality of Evidence)
    • In Adults with Concomitant Influenza and Clinical and Radiographic Evidence of Community-Acquired Pneumonia, Standard Antibacterial Therapy is Recommended to Treat the Community-Acquired Pneumonia in Both Outpatient/Inpatient Settings (Strong Recommendation, Low Quality of Evidence)
  • Routine Use of Corticosteroids is Not Recommended in Adults with Severe Influenza-Related Pneumonia (Conditional Recommendation, Low Quality of Evidence)

Corticosteroids (see Corticosteroids)

Clinical Efficacy

  • Systematic Review/Meta-Analysis of Adjuvant Corticosteroid Therapy in Community-Acquired Pneumonia (J Hosp Med, 2013) [MEDLINE]: 8 randomized controlled trials (n = 1119)
    • Corticosteroids Decrease the Length of Hospital Stay, but Did Not Decrease the Mortality Rate
    • Corticosteroids Decreased the Persistence of CXR Abnormalities and Decreased the Incidence of Delayed Shock
  • Cochrane Database Systematic Review Examining Corticosteroids in Community-Acquired Pneumonia (Cochrane Database Syst Rev, 2017) [MEDLINE]: n = 2264 (from 17 trials)
    • Severe Community-Acquired Pneumonia
      • Corticosteroids Decreased Morbidity and Mortality in Adults with Severe Community-Acquired Pneumonia
      • The Number Needed to Treat for an Additional Beneficial Outcome was 18 Patients (95% CI: 12-49) to Prevent One Death
    • Non-Severe Community-Acquired Pneumonia
      • Corticosteroids Decreased Morbidity, But Not Mortality, for Adults and Children with Non-Severe Community-Acquired Pneumonia
    • Corticosteroids Were Associated with More Adverse Events (Especially Hyperglycaemia), But the Harms Did Not Seem to Outweigh the Benefits
  • Meta-Analysis Examining Corticosteroids in Community-Acquired Pneumonia (Clin Infect Dis, 2018) [MEDLINE]: n = 1506 (from 6 trials)
    • Corticosteroids Decreased the Time to Clinical Stability and Length of Hospital Stay by Approximately 1 Day Without a Decrease in Mortality
    • Corticosteroids Increased the Risk for CAP-Related Rehospitalization and Hyperglycemia
  • Cost-Effectiveness of Corticosteroids in Community-Acquired Pneumonia (Chest, 2019) [MEDLINE]
    • In the Base-Case Analysis, Corticosteroids and Antibiotics Resulted in Savings of $142,795 Per Death Averted
    • In the Probabilistic Analysis, at a Willingness to Pay of $50,000, Combination Corticosteroids and Antibiotics Had a 86.4% Chance of Being Cost-Effective, as Compared to Combination of Placebo and Antibiotics
    • In Cost-Effectiveness Acceptability Curves, the Combination of Corticosteroids and Antibiotics Strategy was Cost-Effective in 87.6-94.3% of Simulations, as Compared with the Combination Placebo and Antibiotics Strategy for a Willingness to Pay Ranging from $0-50,000
    • In Patients with Severe CAP (Pneumonia Severity Index Classes IV and V) the Corticosteroids and Antibiotics Strategy Resulted in Savings of $70,587 and Had a 82.6% Chance of Being Cost-Effective, as Compared to the Combination Placebo and Antibiotics Strategy
    • Conclusion
      • Combination Corticosteroids and Antibiotics is a Cost-Effective Strategy and Results in Considerable Healthcare Cost-Savings, Especially in Patients with Severe Community-Acquired Pneumonia (Pneumonia Severity Index Classes IV and V)

Recommendations (American Thoracic Society and Infectious Diseases Society of America 2019 Clinical Practice Guidelines for the Diagnosis and Treatment of Adults with Community-Acquired Pneumonia) (Am J Respir Crit Care Med, 2019) [MEDLINE]

  • Routine Use of Corticosteroids is Not Recommended in Adults with Non-Severe Community-Acquired Pneumonia (Strong Recommendation, High Quality of Evidence) or Severe Community-Acquired Pneumonia (Conditional Recommendation, Moderate Quality of Evidence)
  • Routine Use of Corticosteroids is Not Recommended in Adults with Severe Influenza-Related Pneumonia (Conditional Recommendation, Low Quality of Evidence)
  • In the Setting of Refractory Septic Shock, Surviving Sepsis Recommendations for the Use of Corticosteroids are Recommended
  • Of Note, There is No Intent that the Above Recommendations Should Override Clinically Appropriate Use of Corticosteroids for Comorbid Diseases, Such as Chronic Obstructive Pulmonary Disease, Asthma, and Autoimmune Disease, in Which Corticosteroids are Supported as a Component of Treatment

Hemodynamic Support

  • Recommendations (Infectious Diseases Society of America, IDSA/American Thoracic Society, ATS 2007 Consensus Guidelines for the Management of Community-Acquired Pneumonia) (Clin Infect Dis, 2007) [MEDLINE]
    • Severe Community-Acquired Pneumonia with Hypotension Requiring Intravenous Fluid Resuscitation Should Be Screened for Occult Adrenal Insufficiency (Moderate Recommendation, Level II Evidence)

Respiratory Support

Types of Respiratory Support

  • Supplemental Oxygen (see Oxygen)
  • Noninvasive Positive-Pressure Ventilation (NIPPV) (see Noninvasive Positive-Pressure Ventilation): may be indicated in select patients
    • Clinical Efficacy
      • Study of NIPPV Use in COPD Exacerbation Associated with Pneumonia (Thorax, 1995) [MEDLINE]
        • Presence of Pneumonia Increased the Failure Rate for NIPPV
      • Prospective Randomized Trial of NIPPV in Severe CAP (Am J Respir Crit Care Med, 1999) [MEDLINE]
        • NIPPV Decreased the Rate of Endotracheal Intubation and ICU Length of Stay
      • Trial of NIPPV in Severe CAP (J Crit Care, 2010) [MEDLINE]
        • NIPPV Had High Failure Rates in Respiratory Failure Associated with CAP
        • Pre/Post-NIPPV Deltas of pO2/FiO2 and Oxygenation Index Predicted Failure
      • Retrospective Cohort Study of NIPPV in CAP (J Crit Care, 2015) [MEDLINE]
        • NIPPV was Frequently Used in Respiratory Failure Associated with CAP, But Failure Rates were High and There was No Impact on Mortality Rate
  • Mechanical Ventilation (see Mechanical Ventilation-General): as required
  • Specific Treatment of Acute Respiratory Distress Syndrome (ARDS) (see Acute Respiratory Distress Syndrome)

Recommendations (Infectious Diseases Society of America, IDSA/American Thoracic Society, ATS 2007 Consensus Guidelines for the Management of Community-Acquired Pneumonia) (Clin Infect Dis, 2007) [MEDLINE]

  • CAP Patients with Hypoxemia/Acute Respiratory Failure Should Receive a Cautious Trial of Noninvasive Positive-Pressure Ventilation (NIPPV) Unless They Require Immediate Intubation Due to Severe Hypoxemia (pO2/FiO2 Ratio <150) and Bilateral Alveolar Infiltrates (Moderate Recommendation, Level I Evidence) (see Noninvasive Positive-Pressure Ventilation)
  • Low Tidal Volume Ventilation (6 mL/kg PBW) is Recommended for Mechanical Ventilation of CAP Patients with Diffuse Bilateral Pneumonia or ARDS (Strong Recommendation, Level I Evidence)

Recommendations (British Thoracic Society Emergency Oxygen Guidelines, 2017) (Thorax, 2017) [MEDLINE]

  • SpO2 Target
    • Oxygen Should Be Prescribed to Achieve a Target Saturation of 94–98% for Most Acutely Ill Patients or 88–92% or Patient-Specific Target Range for Those at Risk of Hypercapnic Respiratory Failure
    • Best Practice is to Prescribe a Target Range for All Hospitalized Patients at the Time of Hospital Admission So that Appropriate Oxygen Therapy Can Be Started in the Event of Unexpected Clinical Deterioration with Hypoxemia and Also to Ensure that the Oximetry Section of the Early Warning Score Can Be Scored Appropriately

Recommendations (British Medical Journal-Oxygen Therapy for Acutely Ill Medical Patients: Clinical Practice Guideline, 2018) (BMJ, 2018) [MEDLINE]

  • Supplemental Oxygen Therapy Should Be Titrated to SpO2 ≤96% (Strong Recommendation)
    • SpO2 >96% likely is Associated with a Small, But Important, Increased Risk of Death without Plausible Clinical Benefit

Follow-Up Chest Imaging After an Episode of Community-Acquired Pneumonia (CAP)

Recommendations-Follow-Up Chest Imaging (American Thoracic Society and Infectious Diseases Society of America 2019 Clinical Practice Guidelines for the Diagnosis and Treatment of Adults with Community-Acquired Pneumonia) (Am J Respir Crit Care Med, 2019) [MEDLINE]

  • In Adults with Community-Acquired Pneumonia Whose Symptoms Have Resolved within 5-7 Days, Routinely Follow-Up Chest Imaging is Not Recommended (Conditional Recommendation, Low Quality of Evidence
    • Reported Rates of Malignancy in Patients Recovering from Community-Acquired Pneumonia Range from 1.3-4%
      • Almost All Patients with Malignancy in the Reported Series were Smokers or Ex-Smokers

Prognosis

Factors Associated with Hospital Readmission for Community-Acquired Pneumonia

Clinical Data

  • Study of Factors Related to Hospital Readmission for Pneumonia (Clin Infect Dis, 2013) [MEDLINE]
    • Hospital Readmission Rate for Pneumonia: 20%
    • Patients with HCAP were 7.5x More Likely to Be Readmitted than Patients with CAP
    • Criteria in HCAP that Associated with the Risk of Hospital Readmission
      • Admission from Long-term Care (adjusted odds ratio [AOR], 2.2 [95% CI, 1.4-3.4])
      • Immunosuppression (AOR, 1.9 [95% CI, 1.3-2.9])
      • Prior Antibiotics (AOR, 1.7 [95% CI, 1.2-2.6])
      • Prior Hospitalization (AOR, 1.7 [95% CI, 1.1-2.5])

Presence of Heart Failure Increases the Mortality Rate of Community-Acquired Pneumonia

Clinical Data

  • Retrospective Cohort Study of Comorbidities in Patients with Community-Acquired Pneumonia (Am J Med Open, 2022) [MEDLINE]: n = 783,702 (61 US hospitals)
    • 27% of Patients Had a Diagnosis of Heart Failure
    • Of These, 26.5% Had Acute Heart Failure, 22.7% Had Chronic Heart Failure, and 51% Had a Diagnosis of Unspecified Heart Failure
    • In Multivariable-Adjusted Models, Having Any Heart Failure was Associated with Increased Mortality (Odds Ratio 1.35; 95% CI: 1.33 – 1.38), as Compared to Those without Heart Failure
    • Increased Mortality was Associated with Acute Heart Failure (Odds Ratio 1.19; 95% CI: 1.15 – 1.22), But Not Chronic Heart Failure (Odds Ratio 0.92, 95% CI: 0.89 – 0.96)

Machine Learning Models May Allow Prediction of Mortality in Community-Acquired Pneumonia

Clinical Data

  • Study of Machine Learning Model for Prediction in Community-Acquired Pneumonia (Chest, 2022) [MEDLINE]: n = 4,531 (derivation cohort) and n = 1,034 (validation cohort)
    • In the Derivation Cohort, the Areas Under the Curve of SepsisFinder Adapted for Community-Acquired Pneumonia (SeF-ML), CURB-65, SOFA, PSI, and qSOFA were 0.801, 0.759, 0.671, 0.799, and 0.642, Respectively, for 30-Day Mortality Prediction
    • In the Validation Study, the Area Under the Curve of SepsisFinder Adapted for Community-Acquired Pneumonia (SeF-ML) was 0.826, Concordant with the Area Under the Curve (0.801) in the Derivation Data (P = 0.51)
    • The Area Under the Curve of SepsisFinder Adapted for Community-Acquired Pneumonia (SeF-ML) was Significantly Higher than Those of CURB-65 (0.764; P = .03) and qSOFA (0.729, P = .005)
      • However, it Did Not Differ Significantly from Those of PSI (0.830; P = .92) and SOFA (0.771; P = .14)
    • SepsisFinder Adapted for Community-Acquired Pneumonia (SeF-ML) Shows Potential for Improving Mortality Prediction in Patients with Community-Acquired Pneumonia, Using Structured Health Data

References

General

Epidemiology

Microbiology

Diagnosis

General

Chest X-Ray (see Chest X-Ray)

Serum Procalcitonin (see Serum Procalcitonin)

Nasal Influenza Testing (see Influenza Virus)

Clinical

General

Clinical-Pneumonia Scoring

Prevention

Treatment

General

Antibiotics

Corticosteroids (see Corticosteroids)

Respiratory Support

Prognosis