Tourniquet ischemia test for the diagnosis of complex regional pain syndrome


  • The tourniquet ischemia test (IT) has a high positive predictive value (PPV) of 85% for diagnosis of complex regional pain syndrome (CRPS) and could be a useful confirmatory test, but low sensitivity (49%) means it is not appropriate for screening.

Why this matters

  • CRPS is usually diagnosed based on clinical symptoms and history due to the absence of any definitive biomarker or test.

  • The IT was developed following a researcher’s observation that distal pain increased with elevation and decreased with lowering of the affected area in patients diagnosed with reflex sympathetic dystrophy and suffering continuous distal pain.

  • The IT is a simple, time-efficient and inexpensive test, but is not currently in common use for diagnosing suspected CRPS. Hence, there is limited evidence as to the diagnostic performance or potential of this test.