types of shock
Reading File
Reading File
Searching the Web
types of shock hypovolemic cardiogenic distributive obstructive clinical overview
Searching PubMed
shock classification
Finding Sources
Shock is acute circulatory failure causing inadequate tissue oxygen delivery and organ dysfunction. It is commonly classified into four main types:
| Type | Main problem | Common causes | Typical clues |
|---|---|---|---|
| Hypovolemic | Too little circulating intravascular volume, causing reduced preload and cardiac output | Hemorrhage: trauma, GI bleed, ruptured ectopic pregnancy. Non-hemorrhagic fluid loss: vomiting, diarrhea, burns, dehydration | Tachycardia, cold clammy skin, weak pulse, low JVP, oliguria |
| Cardiogenic | Pump failure of the heart, causing low cardiac output | Acute MI, severe heart failure, myocarditis, serious arrhythmia, acute valvular failure | Hypotension, raised JVP, pulmonary edema, cool extremities |
| Obstructive | Mechanical blockage to cardiac filling or blood flow | Cardiac tamponade, massive pulmonary embolism, tension pneumothorax | Hypotension with raised JVP; cause-specific signs such as muffled heart sounds in tamponade, unilateral absent breath sounds in tension pneumothorax |
| Distributive | Marked vasodilation and maldistribution of blood flow, with low systemic vascular resistance | Septic shock most common; anaphylaxis; neurogenic shock; adrenal crisis | Often warm, flushed extremities and bounding pulse early, especially in sepsis; may become cold late |
A simplified mechanism-based memory aid:
- Empty tank: hypovolemic shock
- Failed pump: cardiogenic shock
- Blocked circulation: obstructive shock
- Dilated pipes: distributive shock
Mixed shock can occur, for example trauma with both hemorrhage and tension pneumothorax, or sepsis causing myocardial depression.
Typical features of shock overall include altered mental status, tachycardia, hypotension, cool skin in many forms, low urine output, and elevated lactate. Hypotension may be a late sign, so tissue hypoperfusion should be recognized early. This four-category classification is supported by Merck’s clinical overview and Bailey and Love’s Short Practice of Surgery, p. 731-736.
This is a shared conversation. Sign in to Orris to start your own chat.