What is the diagnostic threshold concept in acute compartment syndrome and the recommended management step if elevated?

• A. High suspicion with pain out of proportion and pain on passive stretch; measure pressures and perform fasciotomy if delta pressure <30 mmHg.
• B. Treat with analgesics and observe.
• C. Assess only pulses; if present, no action is needed.
• D. Initiate antibiotics first, then reassess.

Answer: (A)

In acute compartment syndrome, the goal is to prevent muscle and nerve ischemia by recognizing when pressure inside a closed fascial compartment compromises blood flow. The practical diagnostic threshold uses the delta pressure, which is the difference between the diastolic blood pressure and the intracompartmental pressure. When this delta is less than about 30 mmHg, perfusion is inadequate and urgent action is needed to prevent irreversible damage. Clinically, early warning signs include pain that is out of proportion to exam and pain with passive stretch, which should prompt measurement of compartment pressures if the diagnosis is uncertain. If the measured pressures show a delta pressure under 30 mmHg, the recommended management is fasciotomy to decompress the compartment. Analgesics or observation alone miss evolving ischemia, pulses can be present despite rising pressure, and antibiotics are not appropriate for this acute vascular issue.