Abstract WP124: Practice Variation in the Management of Aneurysmal Subarachnoid Hemorrhage- A Survey of US and Canadian Emergency Medicine Physicians

Abstract

Introduction: To rule out sub-arachnoid hemorrhage (SAH) national guidelines for emergency physicians recommends obtaining a non-contrast CT scan and, if negative, a lumbar puncture. However, anecdotal evidence suggests recent adoption of CT non-contrast alone in patients presenting within six hours from symptom onset and an increase in the use of a newer imaging modality, CT angiogram (CTA). Our aim was to examine emergency physicians’ diagnostic approach to SAH diagnosis and their adherence to the current guidelines. Method: We developed, validated, and distributed a survey to emergency physicians at three different emergency departments: Site 1) Stanford Healthcare, California, 2) Intermountain Healthcare, Utah, and 3) The Ottawa Hospital, Ottawa, Ontario. We surveyed emergency physicians with questions on test performance for SAH detection and case based scenarios to assess adherence to guidelines. Results were presented as proportions with 95% CIs. Results: Of the 216 physicians surveyed, we received 168 responses (77.8%). The responses by site were: 1) (n= 38, 23.2%), 2) (n=70, 42.7%), 3) (n=56, 34.1%). Most physicians indicated that non-contrast CT imaging within a 6-hour window detects >90% of SAH in those with a confirmed SAH [n=150 ( 89.3%, 95%CI 83.6 - 93.5)]. In response to the case based scenarios, a majority of the physicians indicated that they would use a non-contrast CT with an additional CTA [n=110 ( 65.5%, 95%CI 57.8- 72.6)], some indicated an additional LP [n=57 (33.9%, 95%CI 26.8 - 41.6)], and a few indicated both an additional CTA and LP[n=16 (9.5%, 95%CI 5.5-15.0)]. We also observed practice site variation in the proportion of physicians who indicated that they would use CTA: 1) (n=25/38, 65.8%), 2) (n= 54/70, 77.1%), and 3) (n=28/56, 50.0%) (p= 0.006). Conclusion: Survey responses indicated a significant variation in the emergency physicians’ use of diagnostic imaging for SAH and divergence from current guidelines. In our future studies, we will explore the reasons for the practice variation and increasing use of CTA as a diagnostic modality in SAH evaluation.