Cardiovascular

Obstructive Shock Trio

High-risk PE vs Tamponade vs Tension Pneumothorax

Obstructive Shock Trio
Feature	High-risk PE	Tamponade	Tension PTX
Mechanism
Mechanism	Acute mechanical RV outflow obstruction by clot	Pericardial pressure abolishes filling gradient	Intrapleural pressure collapses venous return + mediastinal shift
Assessment
JVP / CVP	Elevated	Elevated; prominent x descent; pulsus paradoxus	Elevated
Lung exam	Clear	Clear	Unilateral absent breath sounds ± tracheal deviation (late)
POCUS	RV dilation, McConnell sign, ± clot-in-transit	Effusion + RA/RV diastolic collapse, plethoric IVC, swinging heart	Absent lung sliding + shift; do NOT delay decompression for imaging when unstable
RV findings	Dilated, strained RV	Compressed chambers (external squeeze)	Underfilled/small RV — preload is choked off
BP	Hypotension; syncope common	Hypotension with exaggerated pulsus paradoxus	Precipitous collapse, especially in the ventilated patient
Traps & pitfalls
Key clue	Prostrating hypotension with clear lungs + acute RV strain	Known effusion (malignancy, uremia, viral pericarditis, dialysis)	Sudden deterioration on a ventilator or after line/chest procedure
Management
Immediate treatment	Anticoagulation + urgent reperfusion (systemic lysis / catheter / surgical embolectomy); cautious small-volume fluids only if RV underfilled	Pericardiocentesis — fluids are a bridge only	Immediate needle decompression → chest tube, before imaging if crashing

Acute mechanical RV outflow obstruction by clot

Elevated

Clear

RV dilation, McConnell sign, ± clot-in-transit

Dilated, strained RV

Hypotension; syncope common

Prostrating hypotension with clear lungs + acute RV strain

Anticoagulation + urgent reperfusion (systemic lysis / catheter / surgical embolectomy); cautious small-volume fluids only if RV underfilled

For healthcare-professional education. Clinical decisions require patient-specific assessment and local protocols.