Diagnosis of Subarachnoid Hemorrhage

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See related article, pages 1216–1221. When I began practicing emergency medicine 25 years ago, a stroke patient’s arrival to the emergency department (ED) did not elicit the frenetic burst of activity that it currently does. For that matter, neither did the arrival of a heart attack patient—until the approval of thrombolytic treatment for myocardial infarction. For patients with cerebrovascular emergencies, new treatment options such as thrombolytics and pro-coagulants demand earlier and accurate diagnosis. The shift to early aneurysm obliteration for aneurysmal subarachnoid hemorrhage (SAH) makes its early and accurate diagnosis equally important. Forty percent of patients with SAH die, and 30% of survivors are left with significant neurological disability1; however, nearly half of all patients present in good clinical condition.2 In this group, early treatment prevents rebleeding and results in excellent outcomes. Unfortunately, numerous investigations over several continents and decades document that physicians miss the diagnosis of SAH with a disappointing frequency.3–10 In this issue of Stroke ,11 Vermeulen and Schull present data suggesting that Canadian emergency physicians miss the diagnosis of SAH in 5.4% of cases. Although this may seem like a high miss rate, it is much lower than what has been previously reported. A 2000 review of the subject showed that SAH was misdiagnosed in 32% of 685 cases pooled from 4 large studies.12 The average time delay was 6 days. Most misdiagnosed patients present in good clinical condition but their condition often deteriorates by the time of the second visit. Analysis suggests 3 recurring, largely preventable errors are responsible for physician misdiagnosis: lack of awareness of the spectrum of presentation of SAH, failure to perform (and understand the limitations of) computed tomographic imaging (CT scan), and failure to …