Compartment Syndrome
Rising pressure inside a closed fascial compartment collapses the capillary perfusion gradient, so muscle and nerve die while the major artery stays patent and the distal pulse stays palpable.
Definition
Acute compartment syndrome is a rise in pressure within a closed myofascial compartment causing local tissue ischaemia. No pressure value defines it. The diagnosis is clinical, and the two key findings are pain out of proportion to the associated injury and pain on passive movement of the muscles of the involved compartments.
First principles
A closed compartment turns swelling into ischaemia
Muscle, nerve and vessels sit inside relatively non-compliant fascia. Bleeding, oedema, reperfusion swelling or a constricting cast adds volume the compartment cannot accommodate, so tissue pressure rises. That single fact sets the whole treatment: the only reliable way to lower the pressure is to open the container. Releasing a circumferential dressing is the same manoeuvre one layer further out, which is why it comes first and why it is never enough on its own.
This page is exam revision material, not medical advice, and must not be used for patient care. Always check drug doses against the BNF and current guidance. Full disclaimer.