Definition
- Pulsus Paradoxus: decreased systolic blood pressure with inspiration
- Observed in Arterial Line Waveform (see Arterial Line, [[Arterial Line]])
Etiology
Cardiac
- Cardiogenic Shock (see Cardiogenic Shock, [[Cardiogenic Shock]])
- Constrictive Pericarditis (see Constrictive Pericarditis, [[Constrictive Pericarditis]])
- Epidemiology: pulsus paradoxus is less common in constrictive pericarditis
- Hypovolemia (see Hypovolemic Shock, [[Hypovolemic Shock]])
- Epidemiology: in sepsis
- Respiratory Pulse Pressure Variation, Delta PP ((Max-Min Pulse Pressure)/Average Pulse Pressure), Predicts Cardiac Output Response to an Intravenous Fluid Challenge Better than CVP and PCWP (Am J Resp Crit Care Med, 2000) [MEDLINE]
- Tamponade/Pericardial Effusion (see Tamponade, [[Tamponade]] and Pericardial Effusion, [[Pericardial Effusion]])
- Epidemiology: pulsus paradoxus is commonly observed in the setting of tamponade
- Physiology: pulsus paradoxus is observed during spontaneous breathing
- Diagnosis
- Echocardiogram
- Diastolic RV and LV Collapse
- Systolic RA and LA Collapse
- Increased Variability in Mitral (>25%) Inflow Velocity
- Increased Variability in Tricuspid (>40%) Inflow Velocity
Pulmonary
- Acute Pulmonary Embolism (PE) (see Acute Pulmonary Embolism, [[Acute Pulmonary Embolism]])
- Physiology: RV outflow obstruction
- Asthma (see Asthma, [[Asthma]])
- Epidemiology: pulsus paradoxus is common in asthma
- Physiology:
- Chronic Obstructive Pulmonary Disease (COPD) (see Chronic Obstructive Pulmonary Disease, [[Chronic Obstructive Pulmonary Disease]])
- Tension Pneumothorax (see Pneumothorax, [[Pneumothorax]])
Other
- Abdominal Compartment Syndrome (see Abdominal Compartment Syndrome, [[Abdominal Compartment Syndrome]])
- Physiology: due to transmission of high intra-abdominal pressures to thorax -> impaired right-sided venous return
- Anaphylaxis (see Anaphylaxis, [[Anaphylaxis]])
- Superior Vena Cava (SVC) Syndrome (see Superior Vena Cava Syndrome, [[Superior Vena Cava Syndrome]])
- Physiology: RV inflow obstruction
References
- Relation between respiratory changes in arterial pulse pressure and fluid responsiveness in septic patients with acute circulatory failure. Am J Respir Crit Care Med. 2000 Jul;162(1):134-8 [MEDLINE]
- Focused critical care echocardiography. Crit Care Med. 2013;41:2618–2626 [MEDLINE]
- Advanced echocardiography for the critical care physician: Part 1. Chest. 2014;145:129–134 [MEDLINE]
- Advanced echocardiography for the critical care physician: Part 2. Chest. 2014;145:135–142 [MEDLINE]