title: "Shock: Bedside Pattern Recognition"
Shock: Bedside Pattern Recognition
Q: Shock bedside framework? A: pump / pipes / volume
Shock Types as Quadrants
Cardiac Output (CO) vs Systemic Vascular Resistance (SVR)
↑ SVR (high afterload)↓ SVR (low afterload)
Low CO + High SVR
Hypovolaemic • Cardiogenic • Obstructive
- • Cold peripheries
- • Tachycardia
- • Narrow pulse pressure
CO preserved + High SVR
Compensated states (early shock)
- • Look for subtle hypoperfusion
- • Check lactate, mentation, UO
High CO + Low SVR
Distributive (early sepsis/anaphylaxis)
- • Warm peripheries
- • Bounding pulses
Low CO + Low SVR
Late distributive / mixed shock
- • Decompensation
- • Consider concurrent cardiogenic features
↓ CO (weak pump)↑ CO (strong pump)
3 questions that narrow it fast
| Question | If YES | Think |
|---|---|---|
| Are peripheries warm with wide pulse pressure? | Warm shock | Distributive (early) |
| Is JVP clearly elevated? | Obstructed/pump failing | Cardiogenic / obstructive |
| Is there a plausible volume loss story? | Bleeding/dehydration | Hypovolaemic |
Quick “pattern table” (exam-friendly)
| Shock type | Peripheries | JVP | Lungs | Typical early move |
|---|---|---|---|---|
| Hypovolaemic | Cold | Low | Clear | Volume resus (+ blood if haemorrhage) |
| Distributive (early) | Warm | Low/normal | Often clear | Fluids + treat cause (e.g. sepsis/anaphylaxis) |
| Cardiogenic | Cold | High | Wet | Cautious fluids, inotropes/vasopressors, treat cause |
| Obstructive | Cold | High | Variable | Fix obstruction (PE, tamponade, tension pneumothorax) |
Warning
Hypoperfusion can be present without hypotension — BP is a late sign. Assess mentation, urine output, and lactate, not BP alone.
What to say on ward round / in ED (sounds senior)
One-liner template
"This looks like shock with hypoperfusion (). Pattern is most consistent with ** shock** because ___ (JVP/peripheries/lungs/story). I've started ___ and need ___."
Source: CC Bible; ATLS; local ICU/ED shock teaching.