creation date: 2026-09-01 16:35
tags: Pathologies
Obstructive Shock
Background
Definitions
Shock is defined as a life-threatening condition of circulatory failure. It is a state of cellular tissue hypoxia due to inadequate oxygen delivery for the metabolic demands.
The effects of shock are initially reversible but can deteriorate to an irreversible state with multiorgan failure and death.
Four types of shock are recognized, of which multifactorial shock is possible. The specifics of each type are described in their respective pages:
- Distributive (66% – 62% septic shock, 4% other)
- Cardiogenic (16%)
- Hypovolemic (16%)
- Obstructive (2%)
The general approach to undifferentiated shock is described separately. This articles describes specific findings and treatment of this type of shock.
Etiology
Obstructive shock occurs due to obstruction of heart or great vessels. This results in the inability for heart to circulate blood and thus decreased cardiac output.
Pulmonary vascular
- Due to right ventricular failure from hemodynamically significant pulmonary embolism or severe pulmonary hypertension and heart is unable to overcome pulmonary resistance
Mechanical
- A number of causes can cause mechanical obstruction which includes tension pneumothorax, cardiac tamponade, constrictive pericarditis, and restrictive cardiomyopathy.
Risk Factors
Clinical Presentation
Signs & Symptoms
Vitals:
- Tachycardia (may be normal on beta blocker)
- Hypotension
- Tachypnea (unless severe shock)
- SpO2 usually normal (unless severe)
- Decreased pulse pressure
Presents with hypotension usually without signs of fluid overload or reduced preload but with distended neck veins.
- Subacute cardiac tamponade may have signs of fluid overload
- Pericardial tamponade may find effusion on imaging
- PE or ptx may have dilated RV and small LV
History & Physical Exam
Diagnosis
Criteria
Shock is a clinical diagnosis.