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)

Alcohol Abuse (see Ethanol)

Aspiration

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 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
    • 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]

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 Mechanical Ventilation (see 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

Viral

Bacterial

Fungal

Parasitic


Diagnosis

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

  • 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 with CAP Should 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 CAP 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 og 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

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

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
  • 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

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

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 (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

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 in the Following
      • Any Patient with at Least One of the Following
        • T >100 °F (37.8 °C)
        • Heart Rate >100 beats/min
        • Respiratory Rate >20 breaths/min
      • Any Patient with at Least Two of the Following
        • Crackles (Rales)
        • Decreased Breath Sounds
        • Absence of asthma

Recommendations (Infectious Diseases Society of America, IDSA/American Thoracic Society, ATS 2007 Consensus Guidelines for the Management of CAP) (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 CT (see Chest Computed Tomography)

  • Findings
    • Alveolar and/or Interstitial Infiltrates
    • Chest CT has Higher Sensitivity for the Detection of Infiltrates than CXR
  • Recommendations (Infectious Diseases Society of America, IDSA/American Thoracic Society, ATS 2007 Consensus Guidelines for the Management of CAP) (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 Culture (see Blood Culture)

  • Recommendations (Infectious Diseases Society of America, IDSA/American Thoracic Society, ATS 2007 Consensus Guidelines for the Management of CAP) (Clin Infect Dis, 2007) [MEDLINE]
    • Indications
      • Active Alcohol Abuse
      • Asplenia
      • Cavitary Infiltrates
      • Chronic Severe Liver Disease
      • ICU Admission
      • Leukopenia
      • Pleural Effusion
      • Positive Pneumococcal Urinary Antigen Test

Sputum Culture (see Sputum Culture)

  • Methods
    • Endotracheal Tube Aspirate: when patient intubated
    • Expectorated Sputum Culture: when patient 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
  • Recommendations (Infectious Diseases Society of America, IDSA/American Thoracic Society, ATS 2007 Consensus Guidelines for the Management of CAP) (Clin Infect Dis, 2007) [MEDLINE]
    • Indications
      • Active Alcohol Abuse
      • Cavitary Infiltrates
      • Failure of Outpatient Antibiotic Therapy
      • ICU Admission
      • Pleural Effusion
      • Positive Legionella Urinary Antigen Test
      • Positive Pneumococcal Urinary Antigen Test
      • Severe Obstructive/Structural Lung Disease

Urinary Histoplasma Antigen (see Urinary Histoplasma Antigen)

  • May Be Indicated in Select Cases

Urinary Legionella Antigen (see Urinary Legionella Antigen])

  • Technique
    • Urinary Legionella Antigen Remains Positive for Days After the Start of Antibiotic Treatment
  • Recommendations (Infectious Diseases Society of America, IDSA/American Thoracic Society, ATS 2007 Consensus Guidelines for the Management of CAP) (Clin Infect Dis, 2007) [MEDLINE]
    • Indications
      • Active Alcohol Abuse
      • Failure of Outpatient Antibiotic Therapy
      • ICU Admission
      • Pleural Effusion
      • Recent Travel within Past 2 wks

Urinary Pneumococcal Antigen (see Urinary Pneumococcal Antigen)

  • Technique
    • Urinary Pneumococcal Antigen Remains Positive for Days After the Start of Antibiotic Treatment
  • Recommendations (Infectious Diseases Society of America, IDSA/American Thoracic Society, ATS 2007 Consensus Guidelines for the Management of CAP) (Clin Infect Dis, 2007) [MEDLINE]

Nasal Influenza Testing (see Influenza Virus)

  • May Be Indicated

Bronchoscopy (see Bronchoscopy)

  • Procedures
    • Bronchoalveolar Lavage (BAL)
  • Recommendations (Infectious Diseases Society of America, IDSA/American Thoracic Society, ATS 2007 Consensus Guidelines for the Management of CAP) (Clin Infect Dis, 2007) [MEDLINE]
    • Bronchoscopy May Be Indicated for Patient Admitted to the ICU

Thoracentesis (see Thoracentesis, [[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, [[Pneumonia]])

  • Definition: lung infiltrate associated with clinical evidence that an infiltrate is of an infectious origin (new onset of fever, purulent sputum, leukocytosis, and decline in oxygenation)

Community-Acquired Pneumonia (CAP)

  • Definition: pneumonia which occurs either as outpatient or within 48 hrs of hospital admission
  • 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]
    • Major Criteria
      • Respiratory Failure with Requirement for Invasive Mechanical Ventilation
      • Septic Shock with Vasopressor Requirement
    • Minor Criteria
      • Altered Mental Status
      • Hypotension Requiring Aggressive Intravenous Fluid Resuscitation
      • Hypothermia with Core Temperature <36 Degrees C
      • Leukopenia with WBC <4000 cell/mm3
      • Multilobar Infiltrates
      • pO2/FiO2 Ratio ≤250
      • Respiratory Rate ≥30 breaths/min
      • Thrombocytopenia with Platelets <100k cell/mm3
      • Uremia with BUN ≥20 mg/dL

Healthcare-Associated Pneumonia (HCAP)

  • Definition: pneumonia occurring in a patient who has the following risk factors for multidrug-resistant pathogens
    • Chronic Hemodialysis Within 30 Days
    • Family Member with a Multidrug-Resistant Pathogen
    • Home Intravenous Infusion Therapy (Antibiotics, etc)
    • Home Wound Care
    • Residence in a Long-Term Nursing Home/Extended Care Facility
    • Stay in an Acute Care Hospital for ≥2 Days in the Last 90 Days

Hospital-Acquired Pneumonia (HAP) (see Hospital-Acquired Pneumonia and Ventilator-Associated Pneumonia, [[Hospital-Acquired Pneumonia and Ventilator-Associated Pneumonia]])

  • Definition: pneumonia which is not incubating at the time of hospital admission and which occurs ≥48 hrs after admission
    • This Definition Importantly Excludes Any Pneumonia Which is Associated with Mechanical Ventilation

Ventilator-Associated Tracheobronchitis

  • Definition: fever (without another recognizable cause) associated with new or increased sputum production, positive endotracheal aspirate culture (>10 to the 6th CFU/mL) yielding a new bacteria and no radiographic evidence of pneumonia (Crit Care, 2005) [MEDLINE]

Ventilator-Associated Pneumonia (VAP) (see Hospital-Acquired Pneumonia and Ventilator-Associated Pneumonia, [[Hospital-Acquired Pneumonia and Ventilator-Associated Pneumonia]])

  • Definition: pneumonia which occurs >48 hours after endotracheal intubation
  • Clinical Types of Ventilator-Associated Pneumonia
    • Early Onset Ventilator-Associated Pneumonia (Within 5 Days of Intubation): usually results from aspiration
    • Late Onset Ventilator-Associated Pneumonia (After 5 Days of Intubation): usually caused by antibiotic-resistant pathogens and is associated with increased morbidity and mortality

Clinical-Pneumonia Scoring

Clinical Pneumonia Scoring Systems

  • Pneumonia Severity Index (PSI)
  • CURB-65
  • SOFA

Clinical Data

  • Spanish Cohort Study Comparing Community-Acquired Pneumonia (CAP) Severity Indices in Predicting the In-Hospital Mortality Rate (Am J Respir Crit Care Med, 2017) [MEDLINE]: n = 6874
    • Overall 6.4% of Patients Died in the Hospital
    • Most Accurate Predictors: PSI > CURB-65 > mSOFA> CRB > qSOFA > SIRS
    • qSOFA and CRB (Confusion, Respiratory Rate and Blood Pressure) Criteria Outperformed SIRS and Had Better Clinical Usefulness as Prompt Tools for CAP patients in the Emergency Department
    • PSI (Pneumonia Severity Index) was More Accurate at Predicting In-Hospital Mortality than mSOFA and CURB-65

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

  • Types of Vaccination
  • Clinical Efficacy
    • Standing Orders Have Been Demonstrated to Be the Most Effective Means of Improving Vaccination Rates in Medical Offices/Hospitals/Long-Term Care Settings (JAMA, 2003) [MEDLINE]

Smoking Cessation (see Tobacco, [[Tobacco]])

  • Smoking is a Risk Factor for Legionella Infection and Invasive Pneumococcal Disease
  • Recommendations (Infectious Diseases Society of America, IDSA/American Thoracic Society, ATS 2007 Consensus Guidelines for the Management of CAP) (Clin Infect Dis, 2007) [MEDLINE]
    • Smoking Cessation is Recommended for Smokers Hospitalized with CAP (Moderate Recommendation, Level III Evidence)
    • Smokers Who Will Not Quit Should Be Vaccinated for Both Pneumococcus and Influenza (Weak Recommendation, Level III Evidence)

Treatment of Community-Acquired Pneumonia (CAP)

Site of Care

Clinical Data-Hospital Admission

  • The Decision to Admit a Patient for CAP is the Most Costly Issue in the Management of CAP
    • 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

  • Study of Association Between ICU Admission and Mortality in Patients with Pneumonia ( JAMA, 2015) [MEDLINE]
    • Among Medicare Beneficiaries Hospitalized with Pneumonia, ICU Admission of Patients for Whom the Decision Appeared to Be Discretionary was Associated with Improved Survival and No Significant Difference in Costs

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

  • Severity of Illness Scoring (CURB-65 or PSI) is Recommended to Identify Patients with CAP Who May Be Candidates for Outpatient Treatment (Strong Recommendation, Level I Evidence)
    • CURB-65 Criteria: Confusion, Uremia, Respiratory Rate, Low Blood Pressure, Age ≥65 y/o)
    • Pneumonia Severity Index (PSI)
  • Objective Criteria (CURB-65 or PSI) Should Be Supplemented with Provider Judgement (Regarding the Patient’s Ability to Take Oral Meds, Patient’s Outpatient Support System, etc) (Strong Recommendation, Level II Evidence)
  • For Patients with CURB-65 ≥2, Hospitalization or More Intensive Home Health Care Services are Recommended (Moderate Recommendation, Level III Evidence)
  • Direct ICU Admission is Required for Patients with Either of the Two Major Criteria for Severe CAP (Septic Shock Requiring Vasopressors or Respiratory Failure Requiring Invasive Mechanical Ventilation) (Strong Recommendation, Level II Evidence)
  • Direct ICU or Stepdown Unit Admission is Recommended for Patients with 3 of the Minor Criteria for Severe CAP (Moderate Recommendation, Level II Evidence): however, none of the published criteria for severe CAP adequately distinguishes which patients require ICU admission or validates this recommendation

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

  • xxxx

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 is 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 [aRR], 1.4 [95% CI, 1.3-1.5]), kidney injury (aRR, 1.4 [95% CI, 1.3-1.5]), and secondary C difficile infections (aRR, 1.6 [95% CI, 1.3-1.9]), vancomycin-resistant Enterococcus spp infections (aRR, 1.6 [95% CI, 1.0-2.3]), and secondary gram-negative rod infections (aRR, 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 (Infectious Diseases Society of America, IDSA/American Thoracic Society, ATS 2007 Consensus Guidelines for the Management of CAP) (Clin Infect Dis, 2007) [MEDLINE]

PNEUMONIA EMPIRIC RX
  • Outpatient (Previously Healthy and No Use of Antimicrobials within the Last 3 mo)
    • Doxycycline (Weak Recommendation, Level III Evidence) (see Doxycycline, [[Doxycycline]])
    • Macrolide (Azithromycin, Clarithromycin, Erythromycin) (Strong Recommendation, Level I Evidence) (see Macrolides, [[Macrolides]])
      • In Regions with High Rate (>25%) of Infection with High-Level (MIC ≥16 μg/mL) Macrolide-Resistant Streptococcus Pneumoniae, Consider Use of Alternative Agent (Moderate Recommendation, Level III Evidence)
  • Outpatient (Presence of Co-Morbidities, Such as Chronic Heart/Lung/Liver/Renal Disease, DM, Alcoholism, Malignancy, Asplenia, Immunosuppression, Use of Antimicrobials within the Last 3 mo)
    • β-Lactam (High-Dose Amoxicillin 1 g TID, Amoxicillin-Clavulanic Acid 2 g BID, Ceftriaxone, Cefpodoxime, and Cefuroxime 500 mg BID) + Macrolide (Azithromycin, Clarithromycin, Erythromycin) (Strong Recommendation, Level I Evidence) (see β-Lactam Antibiotics, [[β-Lactam Antibiotics]] and Macrolides, [[Macrolides]])
      • In Regions with High Rate (>25%) of Infection with High-Level (MIC ≥16 μg/mL) Macrolide-Resistant Streptococcus Pneumoniae, Consider Use of Alternative Agent (Moderate Recommendation, Level III Evidence)
    • β-Lactam (High-Dose Amoxicillin 1 g TID, Amoxicillin-Clavulanic Acid 2 g BID, Ceftriaxone, Cefpodoxime, and Cefuroxime 500 mg BID) + Doxycycline (Strong Recommendation, Level II Evidence) (see β-Lactam Antibiotics, [[β-Lactam Antibiotics]] and Doxycycline, [[Doxycycline]])
    • Respiratory Fluoroquinolone (Strong Recommendation, Level I Evidence) (see Fluoroquinolones, [[Fluoroquinolones]]): gemifloxacin, levofloxacin (750 mg qday), moxifloxacin
  • Inpatient (Non-ICU)
    • β-Lactam (Ampicillin, Cefotaxime, Ceftriaxone) + Macrolide (Strong Recommendation, Level I Evidence) (see β-Lactam Antibiotics, [[β-Lactam Antibiotics]] and Macrolides, [[Macrolides]])
    • β-Lactam (Ampicillin, Cefotaxime, Ceftriaxone) + Doxycycline (Strong Recommendation, Level III Evidence) (see β-Lactam Antibiotics, [[β-Lactam Antibiotics]] and Doxycycline, [[Doxycycline]])
    • Respiratory Fluoroquinolone (Strong Recommendation, Level I Evidence) (see Fluoroquinolones, [[Fluoroquinolones]]): gemifloxacin, levofloxacin (750 mg qday), moxifloxacin
  • Inpatient (ICU)
    • β-Lactam (Cefotaxime, Ceftriaxone, Ampicillin-Sulbactam) + Azithromycin (Level II Evidence) (see β-Lactam Antibiotics, [[β-Lactam Antibiotics]] and Azithromycin, [[Azithromycin]])
    • β-Lactam (Cefotaxime, Ceftriaxone, Ampicillin-Sulbactam) + Respiratory Fluoroquinolone (Gemifloxacin, Levofloxacin, Moxifloxacin) (Strong Recommendation, Level I Evidence) (see β-Lactam Antibiotics, [[β-Lactam Antibiotics]] and Azithromycin, [[Azithromycin]])
    • Aztreonam + Respiratory Fluoroquinolone (Gemifloxacin, Levofloxacin, Moxifloxacin) (Strong Recommendation, Level I Evidence) (see Aztreonam, [[Aztreonam]] and Azithromycin, [[Azithromycin]]): preferred regimen for patients with penicillin allergy
  • If Community-Acquired Staphylococcus Aureus (CA-MRSA) is a Concern
    • Add Linezolid or Vancomycin (Moderate Recommendation, Level III Evidence) (see Linezolid, [[Linezolid]] and Vancomycin, [[Vancomycin]])
  • If Pseudomonas is a Concern
    • Anti-Pneumococcal, Anti-Pseudomonal β-Lactam (Piperacillin-Tazobactam, Cefepime, Imipenem, Meropenem) + Levofloxacin (750 mg/day) or Ciprofloxacin (Moderate Recommendation, Level III Evidence) (see β-Lactam Antibiotics, [[β-Lactam Antibiotics]], Levofloxacin, [[Levofloxacin]], and Ciprofloxacin, [[Ciprofloxacin]])
      • For Penicillin-Allergic Patients: substitute aztreonam for β-lactam
    • Anti-Pneumococcal, Anti-Pseudomonal β-Lactam (Piperacillin-Tazobactam, Cefepime, Imipenem, Meropenem) + Aminoglycoside + Azithromycin (Moderate Recommendation, Level III Evidence) (see β-Lactam Antibiotics, [[β-Lactam Antibiotics]], Aminoglycosides, [[Aminoglycosides]], and Azithromycin, [[Azithromycin]])
      • For Penicillin-Allergic Patients: substitute aztreonam for β-lactam
    • Anti-Pneumococcal, Anti-Pseudomonal β-Lactam (Piperacillin-Tazobactam, Cefepime, Imipenem, Meropenem) + Aminoglycoside + Respiratory Fluoroquinolone (Gemifloxacin, Levofloxacin, Moxifloxacin) (Moderate Recommendation, Level III Evidence) (see β-Lactam Antibiotics, [[β-Lactam Antibiotics]], Aminoglycosides, [[Aminoglycosides]], and Fluoroquinolones, [[Fluoroquinolones]])
      • For Penicillin-Allergic Patients: substitute aztreonam for β-lactam

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]

PNEUMONIA RX
  • Acinetobacter (see Acinetobacter, [[Acinetobacter]])
  • Anaerobes (Aspiration Pneumonia) (see Aspiration Pneumonia, [[Aspiration Pneumonia]])
    • First-Line
      • β-Lactam with β-Lactamase Inhibitor: piperacillin-tazobactam (Zosyn), ticarcillin-clavulanic acid (Timentin), ampicillin-sulbactam (Unasyn), or amoxicillin-clavulanic acid (Augmentin) (see β-Lactam Antibiotics, [[β-Lactam Antibiotics]])
      • Clindamycin (see Clindamycin, [[Clindamycin]])
    • Alternative
      • Carbapenem (see Carbapenems, [[Carbapenems]]): imipenem, meropenem, ertapenem
  • Bacillus Anthracis (Anthrax) (see Anthrax, [[Anthrax]])
    • First-Line
      • Ciprofloxacin (Cipro) (see Ciprofloxacin, [[Ciprofloxacin]])
      • Doxycycline (see Doxycycline, [[Doxycycline]]): with a second agent
      • Levofloxacin (Levaquin) (see Levofloxacin, [[Levofloxacin]])
    • Alternative
      • β-Lactam: if susceptible
      • Chloramphenicol (see Chloramphenicol, [[Chloramphenicol]])
      • Clindamycin (see Clindamycin, [[Clindamycin]])
      • Gatifloxacin (Tequin) (see Gatifloxacin, [[Gatifloxacin]])
      • Moxifloxacin (Avelox, Avalox, Avelon) (see Moxifloxacin, [[Moxifloxacin]])
      • Rifampin (see Rifampin, [[Rifampin]])
  • Blastomycosis (see Blastomycosis, [[Blastomycosis]])
    • First-Line
      • Itraconazole (Sporanox) (see Itraconazole, [[Itraconazole]])
    • Alternative
  • Bordetella Pertussis (Pertussis) (see Pertussis, [[Pertussis]])
  • Burkholderia Pseudomallei (Melioidosis) (see Melioidosis, [[Melioidosis]])
    • First-Line
      • Carbapenem (see Carbapenems, [[Carbapenems]]): imipenem, meropenem, ertapenem
      • Ceftazidime (Ceftaz) (see Ceftazidime, [[Ceftazidime]])
    • Alternative
      • Fluoroquinolone (see Fluoroquinolones, [[Fluoroquinolones]]): levofloxacin, moxifloxacin, gatifloxacin, ciprofloxacin
      • Sulfamethoxazole-Trimethoprim (Bactrim, Septra) (see Sulfamethoxazole-Trimethoprim, [[Sulfamethoxazole-Trimethoprim]])
  • Chlamydophila Pneumoniae (see Chlamydophila Pneumoniae, [[Chlamydophila Pneumoniae]])
    • First-Line
    • Alternative
      • Fluoroquinolone (see Fluoroquinolones, [[Fluoroquinolones]]): levofloxacin, moxifloxacin, gatifloxacin
  • Chlamydophila Psittaci (Psittacosis) (see Psittacosis, [[Psittacosis]])
  • Coccidioides Immitis (Coccidioidomycosis) (see Coccidioidomycosis, [[Coccidioidomycosis]])
    • First-Line
      • Fluconazole (Diflucan) (see Fluconazole, [[Fluconazole]])
      • Itraconazole (Sporanox) (see Itraconazole, [[Itraconazole]])
    • Alternative
  • Coxiella Burnetti (Q Fever) (see Q Fever, [[Q Fever]])
  • Enterobacteriaceae (see Enterobacteriaceae, [[Enterobacteriaceae]])
    • First-Line
      • Carbapenem (see Carbapenems, [[Carbapenems]]): imipenem, meropenem, ertapenem
      • Third-Generation Cephalosporin (see Cephalosporins, [[Cephalosporins]])
    • Alternative
      • β-Lactam with β-Lactamase Inhibitor: piperacillin-tazobactam (Zosyn), ticarcillin-clavulanic acid (Timentin), ampicillin-sulbactam (Unasyn), or amoxicillin-clavulanic acid (Augmentin) (see β-Lactam Antibiotics, [[β-Lactam Antibiotics]])
      • Fluoroquinolone (see Fluoroquinolones, [[Fluoroquinolones]]): levofloxacin, moxifloxacin, gatifloxacin
    • Extended-Spectrum β-Lactamase (ESBL) Producer
      • Carbapenem (see Carbapenems, [[Carbapenems]]): imipenem, meropenem, ertapenem
  • Francisella Tularensis (Tularemia) (see Tularemia, [[Tularemia]])
  • Haemophilus Influenzae (β-Lactamase Negative) (see Haemophilus Influenzae, [[Haemophilus Influenzae]])
    • First-Line
    • Alternative
      • Azithromycin (Zithromax) (see Azithromycin, [[Azithromycin]]): azithromycin is more active in vitro against Haemophilus Influenzae than clarithromycin
      • Clarithromycin (Biaxin) (see Clarithromycin, [[Clarithromycin]])
      • Doxycycline (see Doxycycline, [[Doxycycline]])
      • Fluoroquinolone (see Fluoroquinolones, [[Fluoroquinolones]]): levofloxacin, moxifloxacin, gatifloxacin, ciprofloxacin
  • Haemophilus Influenzae (β-Lactamase Positive) (see Haemophilus Influenzae, [[Haemophilus Influenzae]])
    • First-Line
    • Alternative
      • Azithromycin (Zithromax) (see Azithromycin, [[Azithromycin]]): azithromycin is more active in vitro against Haemophilus Influenzae than clarithromycin
      • Clarithromycin (Biaxin) (see Clarithromycin, [[Clarithromycin]])
      • Doxycycline (see Doxycycline, [[Doxycycline]])
      • Fluoroquinolone (see Fluoroquinolones, [[Fluoroquinolones]]): levofloxacin, moxifloxacin, gatifloxacin, ciprofloxacin
  • Histoplasmosis (see Histoplasmosis, [[Histoplasmosis]])
    • First-Line
      • Itraconazole (Sporanox) (see Itraconazole, [[Itraconazole]])
    • Alternative
  • Influenza Virus (see Influenza Virus, [[Influenza Virus]])
    • First-Line: therapy should be started within 48 hrs of onset of symptoms of influenza A (Strong Recommendation, Level I Evidence)
      • Oseltamivir (Tamiflu) (see Oseltamivir, [[Oseltamivir]])
      • Zanamivir (Relenza) (see Zanamivir, [[Zanamivir]])
  • Legionella (Legionellosis) (see Legionellosis, [[Legionellosis]])
    • First-Line
      • Azithromycin (Zithromax) (see Azithromycin)
      • Fluoroquinolone (see Fluoroquinolones, [[Fluoroquinolones]]): levofloxacin, moxifloxacin, gatifloxacin, ciprofloxacin
    • Alternative
  • Mycobacterium Tuberculosis (see Tuberculosis, [[Tuberculosis]])
    • First-Line
    • Alternative
      • Variable
  • Mycoplasma Pneumoniae (see Mycoplasma Pneumoniae, [[Mycoplasma Pneumoniae]])
    • First-Line
    • Alternative
      • Fluoroquinolone (see Fluoroquinolones, [[Fluoroquinolones]]): levofloxacin, moxifloxacin, gatifloxacin
  • Pseudomonas Aeruginosa (see Pseudomonas Aeruginosa, [[Pseudomonas Aeruginosa]])
    • First-Line
      • Anti-Pseudomonal β-Lactam (Ticarcillin, Piperacillin, Ceftazidime, Cefepime, Aztreonam, Imipenem, Meropenem) + Ciprofloxacin or Levofloxacin (750 mg qday) or Aminoglycoside (see β-Lactam Antibiotics, [[β-Lactam Antibiotics]], Ciprofloxacin, [[Ciprofloxacin]], Levofloxacin, [[Levofloxacin]], and Aminoglycosides, [[Aminoglycosides]])
    • Alternative
  • Staphylococcus Aureus (Methicillin-Sensitive, MSSA) (see Staphylococcus Aureus, [[Staphylococcus Aureus]])
    • First-Line
      • Anti-Staphylococcal Penicillin (see Penicillins, [[Penicillins]]): nafcillin, oxacillin, flucloxacillin
    • Alternative
  • Staphylococcus Aureus (Methicillin-Resistant, MRSA) (see Staphylococcus Aureus, [[Staphylococcus Aureus]])
  • Streptococcus Pneumoniae (Penicillin-Sensitive, MIC <2 μg/mL)
    • First-Line
    • Alternative
      • Cephalosporin (see Cephalosporins, [[Cephalosporins]]): cefpodoxime PO, cefprozil PO, cefuroxime PO/IV, cefdinir PO, cefditoren PO, ceftriaxone IV, cefotaxime IV
      • Clindamycin (see Clindamycin, [[Clindamycin]])
      • Doxycycline (see Doxycycline, [[Doxycycline]])
      • Macrolide (see Macrolides, [[Macrolides]])
      • Respiratory Fluoroquinolone (see Fluoroquinolones, [[Fluoroquinolones]]): gemifloxacin, levofloxacin, moxifloxacin
  • Streptococcus Pneumoniae (Penicillin-Resistant, MIC ≥2 μg/mL)
    • First-Line: chose agent based on sensitivity
      • Cefotaxime (Claforan, Cefatam) (see Cefotaxime, [[Cefotaxime]])
      • Ceftriaxone (Rocephin) (see Ceftriaxone, [[Ceftriaxone]])
      • Respiratory Fluoroquinolone (see Fluoroquinolones, [[Fluoroquinolones]]): gemifloxacin, levofloxacin, moxifloxacin
    • Alternative
      • High-Dose Amoxicillin (3 g/day) (see Amoxicillin, [[Amoxicillin]]): for penicillin MIC ≤4 μg/mL
      • Linezolid (Zyvox) (see Linezolid, [[Linezolid]])
      • Vancomycin (see Vancomycin, [[Vancomycin]])
  • Yersinia Pestis (Plague) (see Plague, [[Plague]])
    • First-Line
    • Alternative
      • Doxycycline (see Doxycycline, [[Doxycycline]])
      • Fluoroquinolone (see Fluoroquinolones, [[Fluoroquinolones]]): levofloxacin, moxifloxacin, gatifloxacin, ciprofloxacin

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 CAP (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)

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 CAP 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, [[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]

Corticosteroids (see Corticosteroids, [[Corticosteroids]])

Rationale

  • xxxx

Clinical Efficacy

  • Systematic Review/Meta-Analysis of Adjuvant Corticosteroid Therapy in CAP (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 CAP
      • Corticosteroids Decreased Morbidity and Mortality in Adults with Severe CAP
      • The Number Needed to Treat for an Additional Beneficial Outcome was 18 Patients (95% CI: 12-49) to Prevent One Death
    • Non-Severe CAP
      • Corticosteroids Decreased Morbidity, But Not Mortality, for Adults and Children with Non-Severe CAP
    • 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 CAP (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 CAP (Pneumonia Severity Index Classes IV and V)

Hemodynamic Support

  • Recommendations (Infectious Diseases Society of America, IDSA/American Thoracic Society, ATS 2007 Consensus Guidelines for the Management of CAP) (Clin Infect Dis, 2007) [MEDLINE]
    • Severe CAP Patients 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, [[Oxygen]])
  • Noninvasive Positive-Pressure Ventilation (NIPPV) (see Noninvasive Positive-Pressure Ventilation, [[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, [[Mechanical Ventilation-General]]): as required
  • Specific Treatment of Acute Respiratory Distress Syndrome (ARDS) (see Acute Respiratory Distress Syndrome, [[Acute Respiratory Distress Syndrome]])

Recommendations (Infectious Diseases Society of America, IDSA/American Thoracic Society, ATS 2007 Consensus Guidelines for the Management of CAP) (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, [[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

Prognosis

Hospital Readmission for 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])

References

General

  • Preferences for home vs hospital care among low-risk patients with community-acquired pneumonia. Arch Intern Med 1996; 156:1565–71 [MEDLINE]
  • A prediction rule to identify low-risk patients with community-acquired pneumonia. N Engl J Med. 1997 Jan 23;336(4):243-50 [MEDLINE]
  • The cost of treating community-acquired pneumonia. Clin Ther. 1998 Jul-Aug;20(4):820-37 [MEDLINE]
  • Risk factors for venous thromboembolism in hospitalized patients with acute medical illness: analysis of the MEDENOX Study. Arch Intern Med 2004; 164:963–8 [MEDLINE]
  • Validation of predictive rules and indices of severity for community acquired pneumonia. Thorax 2004; 59:421–7 [MEDLINE]
  • Risk factors of treatment failure in community acquired pneumonia: implications for disease outcome. Thorax 2004;59:960-965 [MEDLINE]
  • Infectious Diseases Society of America/American Thoracic Society Consensus Guidelines on the Management of Community-Acquired Pneumonia in Adults. Clin Infect Dis. 2007 Mar 1;44 Suppl 2:S27-72 [MEDLINE]
  • CDC EPIC Study. Community-Acquired Pneumonia Requiring Hospitalization among U.S. Adults. N Engl J Med. 2015 Jul 30;373(5):415-27. doi: 10.1056/NEJMoa1500245. Epub 2015 Jul 14 [MEDLINE]
  • Management of Adults With Hospital-acquired and Ventilator-associated Pneumonia: 2016 Clinical Practice Guidelines by the Infectious Diseases Society of America and the American Thoracic Society. 2016 Sep 1;63(5):e61-e111. doi: 10.1093/cid/ciw353. Epub 2016 Jul 14 [MEDLINE]
  • Diagnosis and Treatment of Adults with Community-acquired Pneumonia. An Official Clinical Practice Guideline of the American Thoracic Society and Infectious Diseases Society of America. Am J Respir Crit Care Med. 2019 Oct 1;200(7):e45-e67. doi: 10.1164/rccm.201908-1581ST [MEDLINE]

Epidemiology

  • A risk score for identifying methicillin-resistant Staphylococcus aureus in patients presenting to the hospital with pneumonia. BMC Infect Dis. 2013 Jun 6;13:268. doi: 10.1186/1471-2334-13-268 [MEDLINE]
  • Which individuals are at increased risk of pneumococcal disease and why? Impact of COPD, asthma, smoking, diabetes, and/or chronic heart disease on community-acquired pneumonia and invasive pneumococcal disease. Thorax. 2015 Oct;70(10):984-9. doi: 10.1136/thoraxjnl-2015-206780 [MEDLINE]
  • Staphylococcus aureus bacteremic pneumonia. Eur J Clin Microbiol Infect Dis. 2016 Mar;35(3):497-502. doi: 10.1007/s10096-015-2566-8 [MEDLINE]
  • Liver Cirrhosis and Diabetes Mellitus Are Risk Factors for Staphylococcus aureus Infection in Patients with Healthcare-Associated or Hospital-Acquired Pneumonia. Pulm Med. 2016;2016:4706150. doi: 10.1155/2016/4706150 [MEDLINE]
  • Risk Factors for Community-Acquired Pneumonia in Adults: A Systematic Review of Observational Studies. Respiration. 2017;94(3):299-311. doi: 10.1159/000479089 [MEDLINE]
  • Undiagnosed Diabetes Mellitus in Community-Acquired Pneumonia: A Prospective Cohort Study. Clin Infect Dis. 2017 Nov 29;65(12):2091-2098. doi: 10.1093/cid/cix703 [MEDLINE]
  • Risk of Infection in Type 1 and Type 2 Diabetes Compared With the General Population: A Matched Cohort Study. Diabetes Care. 2018 Mar;41(3):513-521. doi: 10.2337/dc17-2131 [MEDLINE]
  • Differences between diabetic and non-diabetic patients with community-acquired pneumonia in primary care in Spain. BMC Infect Dis. 2019 Nov 15;19(1):973. doi: 10.1186/s12879-019-4534-x [MEDLINE]
  • The Glycemic Gap and 90-Day Mortality in Community-acquired Pneumonia. A Prospective Cohort Study. Ann Am Thorac Soc. 2019 Dec;16(12):1518-1526. doi: 10.1513/AnnalsATS.201901-007OC [MEDLINE]
  • Methicillin-resistant Staphylococcus aureus pneumonia in diabetics: a single-center, retrospective analysis. Chin Med J (Engl). 2019 Jun 20;132(12):1429-1434. doi: 10.1097/CM9.0000000000000270 [MEDLINE]
  • Diabetes and the Risk of Infection: A National Cohort Study. Diabetes Metab J. 2019 Dec;43(6):804-814. doi: 10.4093/dmj.2019.0071 [MEDLINE]
  • Effect of tobacco smoking on the risk of developing community acquired pneumonia: A systematic review and meta-analysis. PLoS One. 2019 Jul 18;14(7):e0220204. doi: 10.1371/journal.pone.0220204. eCollection 2019 [MEDLINE]

Etiology

  • Etiology of community-acquired pneumonia treated in an ambulatory setting. Resp Medicine 2005; 99:60
  • A comparative study of community-acquired pneumonia patients admitted to the ward and the ICU. Chest 2008; 133:610
  • Microbial aetiology of community-acquired pneumonia and its relation to severity. Thorax 2011; 66:340
  • EPIC Study. Community-Acquired Pneumonia Requiring Hospitalization among U.S. Adults. N Engl J Med. 2015 Jul 30;373(5):415-27. doi: 10.1056/NEJMoa1500245 [MEDLINE]

Diagnosis

General

  • Contributions of symptoms, signs, erythrocyte sedimentation rate, and C-reactive protein to a diagnosis of pneumonia in acute lower respiratory tract infection. Br J Gen Pract. 2003;53:358–64 [MEDLINE]

Chest X-Ray (see Chest X-Ray)

  • Prediction of pneumonia in outpatients with acute cough—a statistical approach. J Chronic Dis. 1984;37:215–25 [MEDLINE]
  • Clinical criteria for the detection of pneumonia in adults: guidelines for ordering chest roentgenograms in the emergency department. J Emerg Med. 1989;7:263–8 [MEDLINE]
  • Decision rules and clinical prediction of pneumonia: evaluation of low-yield criteria. Ann Emerg Med. 1989;18:13–20 [MEDLINE]
  • Clinical prediction rule for pulmonary infiltrates. Ann Intern Med. 1990;113:664–70 [MEDLINE]
  • Comparison of physician judgment and decision aids for ordering chest radiographs for pneumonia in outpatients. Ann Emerg Med. 1991;20:1215–9 [MEDLINE]
  • Does this patient have community-acquired pneumonia? Diagnosing pneumonia by history and physical examination. JAMA. 1997;278:1440–5 [MEDLINE]
  • Predicting pneumonia in adults with respiratory illness. Am Fam Physician. 2007 Aug 15;76(4):560-2 [MEDLINE]

Serum Procalcitonin (see Serum Procalcitonin)

  • High serum procalcitonin concentrations in patients with sepsis and infection. Lancet 1993; 341:515–8 [MEDLINE]
  • Accuracy of procalcitonin for sepsis diagnosis in critically ill patients: systematic review and meta-analysis. Lancet Infect Dis. 2007;7(3):210 [MEDLINE]
  • Procalcitonin to initiate or discontinue antibiotics in acute respiratory tract infections. Cochrane Database Syst Rev. 2012 Sep 12;(9):CD007498. doi: 10.1002/14651858.CD007498.pub2 [MEDLINE]
  • Procalcitonin to guide initiation and duration of antibiotic treatment in acute respiratory infections: an individual patient data meta‐analysis. Clin Infect Dis 2012: 55(5):651–662 [MEDLINE]
  • An ESICM systematic review and meta‐analysis of procalcitonin‐guided antibiotic therapy algorithms in adult critically ill patients. Intensive Care Med 2012: 38(6):940–949 [MEDLINE]
  • Procalcitonin‐guided therapy in intensive care unit patients with severe sepsis
and septic shock—a systematic review and meta‐analysis. Crit Care 2013: 17(6):R291 [MEDLINE]
  • Procalcitonin‐guided antibiotic therapy: a systematic review and meta‐analysis. J Hosp Med 2013: 8(9):530–540 [MEDLINE]
  • Procalcitonin as a diagnostic marker for sepsis: a systematic review and meta‐analysis. Lancet Infect Dis 2013: 13(5):426–435 [MEDLINE]
  • Procalcitonin as a diagnostic marker in differentiating parapneumonic effusion from tuberculous pleurisy or malignant effusion. Clin Biochem. 2013;46(15):1484 [MEDLINE]
  • Biomarkers: what is their benefit in the identification of infection, severity assessment, and management of community-acquired pneumonia? Infect Dis Clin North Am. 2013 Mar;27(1):19-31. Epub 2012 Dec 6 [MEDLINE]
  • Procalcitonin guided antibiotic therapy of acute exacerbations of asthma: a randomized controlled trial. BMC Infect Dis. 2013;13:596. Epub 2013 Dec 17 [MEDLINE]
  • Procalcitonin testing to guide antibiotic therapy for the treatment of sepsis in intensive care settings and for suspected bacterial infection in emergency department settings: a systematic review and cost‐effectiveness analysis. Health Technol Assess 2015: 19(96):v–xxv, 1–236 [MEDLINE]
  • Efficacy and safety of procalcitonin guidance in reducing the duration of antibiotic treatment in critically ill patients: a randomised, controlled, open-label trial. Lancet Infect Dis. 2016 Jul;16(7):819-27. doi: 10.1016/S1473-3099(16)00053-0. Epub 2016 Mar 2 [MEDLINE]
  • Management of Adults With Hospital-acquired and Ventilator-associated Pneumonia: 2016 Clinical Practice Guidelines by the Infectious Diseases Society of America and the American Thoracic Society. Clin Infect Dis. 2016 Sep 1;63(5):e61-e111. doi: 10.1093/cid/ciw353. Epub 2016 Jul 14 [MEDLINE]
  • Efficacy and safety of procalcitonin guidance in reducing the duration of antibiotic treatment in critically ill patients: a randomised, controlled, open-label trial. Lancet Infect Dis. 2016 Jul;16(7):819-27. doi: 10.1016/S1473-3099(16)00053-0. Epub 2016 Mar 2 [MEDLINE]
  • Procalcitonin to initiate or discontinue antibiotics in acute respiratory tract infections. Cochrane Database Syst Rev. 2017 Oct 12;10:CD007498. doi: 10.1002/14651858.CD007498.pub3 [MEDLINE]
  • ProACT Trial. Procalcitonin-Guided Use of Antibiotics for Lower Respiratory Tract Infection. N Engl J Med. 2018 Jul 19;379(3):236-249. doi: 10.1056/NEJMoa1802670 [MEDLINE]

Clinical

General

  • Pleural Effusions at First ED Encounter Predict Worse Clinical Outcomes in Patients With Pneumonia. Chest. 2016;149(6):1509 [MEDLINE]

Clinical-Pneumonia Scoring

  • New Sepsis Definition (Sepsis-3) and Community-acquired Pneumonia Mortality: A Validation and Clinical Decision-making Study. Am J Respir Crit Care Med. 2017 Jun 14. doi: 10.1164/rccm.201611-2262OC [MEDLINE]

Prevention

  • Facilitating influenza and pneumococcal vaccination through standing orders programs. JAMA 2003; 289:1238 [MEDLINE]

Treatment

General

  • The cost of treating community-acquired pneumonia. Clin Ther 1998; 20: 820–37 [MEDLINE]
  • Association of Intensive Care Unit Admission With Mortality Among Older Patients With Pneumonia. JAMA. 2015 Sep 22-29;314(12):1272-9. doi: 10.1001/jama.2015.11068 [MEDLINE]

Antibiotics

  • Variations in etiology of ventilator-associated pneumonia across four treatment sites: implications for antimicrobial prescribing practices. Am J Respir Crit Care Med. 1999;160(2):608-613 [MEDLINE]
  • PneumA Trial. Comparison of 8 vs 15 days of antibiotic therapy for ventilator-associated pneumonia in adults: a randomized trial. JAMA. 2003;290(19):2588-2598 [MEDLINE]
  • Timing of antibiotic administration and outcomes for Medicare patients hospitalized with community-acquired pneumonia. Arch Intern Med 2004; 164:637–44 [MEDLINE]
  • De-escalation in lower respiratory tract infections. Curr Opin Pulm Med. 2006;12(5):364-368 [MEDLINE]
  • De-escalation therapy in ventilator-associated pneumonia. Curr Opin Crit Care. 2006;12(5):452-457 [MEDLINE]
  • Clinical characteristics and treatment patterns among patients with ventilator-associated pneumonia. Chest 2006; 129:1210–1218 [MEDLINE]
  • Antibiotic stewardship: overcoming implementation barriers. Curr Opin Infect Dis. 2011;24(4): 357-362 [MEDLINE]
  • Antimicrobial stewardship programs: mandatory for all ICUs. Crit Care. 2012;16:179. doi:10.1186/cc11853 [MEDLINE]
  • Impact of regular collaboration between infectious diseases and critical care practitioners on antimicrobial utilization and patient outcome. Crit Care Med. 2013;41:2099–2107. doi: 10.1097/CCM.0b013e31828e9863 [MEDLINE]
  • Efficacy of single-dose antibiotic against early-onset pneumonia in comatose patients who are ventilated. Chest. 2013 May;143(5):1219-25. doi: 10.1378/chest.12-1361 [MEDLINE]
  • Antibiotic stewardship in hospital-acquired pneumonia. Chest. 2013;143:1195–1196. doi:10.1378/chest.12-2729 [MEDLINE]
  • Association of azithromycin with mortality and cardiovascular events among older patients hospitalized with pneumonia. JAMA. 2014 Jun 4;311(21):2199-208. doi: 10.1001/jama.2014.4304 [MEDLINE]
  • What can be expected from antimicrobial de-escalation in the critically ill? Intensive Care Med 2014; 40:92–5 [MEDLINE]
  • CAP-START Trial. Antibiotic treatment strategies for community-acquired pneumonia in adults. N Engl J Med. 2015 Apr 2;372(14):1312-23. doi: 10.1056/NEJMoa1406330 [MEDLINE]
  • A Systematic Review of the Definitions, Determinants, and Clinical Outcomes of Antimicrobial De-escalation in the Intensive Care Unit. Clin Infect Dis. 2016 Apr 15;62(8):1009-17. doi: 10.1093/cid/civ1199. Epub 2015 Dec 23 [MEDLINE]
  • Duration of Antibiotic Treatment in Community-Acquired Pneumonia. A Multicenter Randomized Clinical Trial. JAMA Intern Med. 2016 Jul 25. doi: 10.1001/jamainternmed.2016.3633 [MEDLINE]
  • Empirical Anti-MRSA vs Standard Antibiotic Therapy and Risk of 30-Day Mortality in Patients Hospitalized for Pneumonia. JAMA Intern Med. 2020 Feb 17. doi: 10.1001/jamainternmed.2019.7495 [MEDLINE]
  • Appropriate Use of Short-Course Antibiotics in Common Infections: Best Practice Advice From the American College of Physicians. Ann Intern Med. 2021 Apr 6. doi: 10.7326/M20-7355 [MEDLINE]

Corticosteroids (see Corticosteroids, [[Corticosteroids]])

  • Adjuvant steroid therapy in community-acquired pneumonia: a systematic review and meta-analysis. J Hosp Med. 2013 Feb;8(2):68-75 [MEDLINE]
  • Corticosteroids for pneumonia. Cochrane Database Syst Rev. 2017 Dec 13;12:CD007720. doi: 10.1002/14651858.CD007720.pub3 [MEDLINE]
  • Corticosteroids in Patients Hospitalized With Community-Acquired Pneumonia: Systematic Review and Individual Patient Data Metaanalysis. Clin Infect Dis. 2018 Jan 18;66(3):346-354. doi: 10.1093/cid/cix801 [MEDLINE]
  • The Cost-Effectiveness of Corticosteroids for the Treatment of Community-Acquired Pneumonia. Chest. 2019 Apr;155(4):787-794. doi: 10.1016/j.chest.2018.11.001 [MEDLINE]

Respiratory Support

  • Acute respiratory failure in patients with severe community-acquired pneumonia. A prospective randomized evaluation of noninvasive ventilation. Am J Respir Crit Care Med. 1999 Nov;160(5 Pt 1):1585-91 [MEDLINE]
  • Non-invasive mechanical ventilation in acute respiratory failure due to chronic obstructive pulmonary disease: correlates for success. Thorax. 1995 Jul;50(7):755-7 [MEDLINE]
  • Predictors of failure of noninvasive ventilation in patients with severe community-acquired pneumonia. J Crit Care. 2010 Sep;25(3):540.e9-14. doi: 10.1016/j.jcrc.2010.02.012 [MEDLINE]
  • The role of noninvasive positive pressure ventilation in community-acquired pneumonia. J Crit Care. 2015 Feb;30(1):49-54. doi: 10.1016/j.jcrc.2014.09.021. Epub 2014 Oct 2 [MEDLINE]
  • British Thoracic Society Emergency Oxygen Guideline Group BTS Emergency Oxygen Guideline Development Group. BTS guideline for oxygen use in adults in healthcare and emergency settings. Thorax 2017;72(Suppl 1):ii1-90. 10.1136/ thoraxjnl-2016-209729 pmid:28507176 [MEDLINE]
  • Oxygen therapy for acutely ill medical patients: a clinical practice guideline. BMJ. 2018 Oct 24;363:k4169. doi: 10.1136/bmj.k4169 [MEDLINE]

Prognosis

  • Readmission following hospitalization for pneumonia: the impact of pneumonia type and its implication for hospitals. Clin Infect Dis. 2013 Aug;57(3):362-7 [MEDLINE]
  • Editorial commentary: “excess readmissions” for pneumonia: a dilemma with a penalty. Clin Infect Dis. 2013 Aug;57(3):368-9 [MEDLINE]