Clinical Exam or ICP for Compartment Syndrome — Neither is Enough

What’s the Claim?

A meta-analysis of studies about the diagnosis of compartment syndrome that compared the use of intracompartmental pressure (ICP) monitoring to clinical findings, as well as using both ICP and clinical findings together, found that neither clinical examination alone nor ICP monitoring had sufficient predictive value for clinical use. Clinical findings alone were calculated to have a 22% predictive value, and ICP alone offered a 29% predictive value. Used together, the probability of a patient having acute compartment syndrome when both clinical symptoms/signs and ICP suggested it rose to 69%.

How’s It Stack Up?

Meta-analyses are only as good as their sources. Here, the sources were generally good, though they certainly had their soft spots. In particular, as one would expect, the source articles were inconsistent on the topic of the reference standard. No surprise — the perfect study on this diagnosis can never be done, since that would require taking every patient in whom the diagnosis is considered to the operating room, and we don’t take patients to the OR when we’re pretty sure they’re okay. In addition, different studies used different threshold values for “positive” ICP, though most used the difference between the diastolic blood pressure and the ICP measurement and set a threshold for that metric (perfusion pressure) of around 30 mmHg. The studies were fairly consistent about the history and physical findings they used to make the clinical diagnosis, and those are familiar to all orthopaedic surgeons.

What’s Our Take?

Readers of this post have been thinking about the diagnosis of compartment syndrome — and how not to miss it — since their first nights on call as orthopaedic residents. Most of us probably feel like there is nothing new under the sun here, and in one sense, that’s true — a meta-analysis doesn’t invent new data or design new study approaches. What’s neat about this one, though, is how it shows that both “sides” are either right or they’re both wrong. If you don’t like using ICP measurements, and you’re convinced that a good history and your exam alone will do the trick even in ambiguous situations, well, it seems pretty sure that ain’t so. Likewise, for those who really feel that measuring compartmental pressures is a reliable stand-alone, it seems that’s obviously incorrect, too. The definition of a good diagnostic test is one that takes us from an intermediate likelihood of a diagnosis being present before the application of the test to a state of sufficient certainty afterwards. For patients in whom the diagnosis of compartment syndrome is uncertain, this meta-analysis makes a strong case for measuring ICP. CORRelations’ advisor in Fractures & Trauma, Jaimo Ahn, MD, said it well: “If the exam is not clearly positive or clearly negative, obtaining ICP clearly adds diagnostic value.”

Source

Lorange JP, Laverdière C, Corban J, Montreuil J, Harvey EJ. Diagnosis Accuracy for Compartment Syndrome: A Systematic Review and Meta-Analysis. J Orthop Trauma. Published online April 13, 2023. DOI: 10.1097/BOT.0000000000002610.