PT  - JOURNAL ARTICLE
AU  - Walton, Matthew
AU  - Hodgson, Robert
AU  - Eastwood, Alison
AU  - Harden, Melissa
AU  - Storey, James
AU  - Hassan, Taj
AU  - Randall, Marc Stuart
AU  - Hassan, Abu
AU  - Williams, John
AU  - Wade, Ros
TI  - Management of patients presenting to the emergency department with sudden onset severe headache: systematic review of diagnostic accuracy studies
AID  - 10.1136/emermed-2021-211900
DP  - 2022 Mar 30
TA  - Emergency Medicine Journal
PG  - emermed-2021-211900
4099  - http://emj.bmj.com/content/early/2022/03/30/emermed-2021-211900.short
4100  - http://emj.bmj.com/content/early/2022/03/30/emermed-2021-211900.full
AB  - Objective Advances in imaging technologies have precipitated uncertainty and inconsistency in the management of neurologically intact patients presenting to the Emergency Department (ED) with non-traumatic sudden onset severe headache with a clinical suspicion of subarachnoid haemorrhage (SAH). The objective of this systematic review was to evaluate diagnostic strategies in these patients.Methods Studies assessing any decision rule or diagnostic test for evaluating neurologically intact adults with a severe headache, reaching maximum intensity within 1 hour, were eligible. Eighteen databases (including MEDLINE and Embase) were searched. Quality was assessed using QUADAS-2. Where appropriate, hierarchical bivariate meta-analysis was used to synthesise diagnostic accuracy results.Results Thirty-seven studies were included. Eight studies assessing the Ottawa SAH clinical decision rule were pooled; sensitivity 99.5% (95% CI 90.8 to 100), specificity 24% (95% CI 15.5 to 34.4). Four studies assessing CT within 6 hours of headache onset were pooled; sensitivity 98.7% (95% CI 96.5 to 100), specificity 100% (95% CI 99.7 to 100). The sensitivity of CT beyond 6 hours was considerably lower (≤90%; 2 studies). Three studies assessing lumbar puncture (LP; spectrophotometric analysis) following negative CT were pooled; sensitivity 100% (95% CI 100 to 100), specificity 95% (95% CI 86.0 to 98.5).Conclusion The Ottawa SAH Rule rules out further investigation in only a small proportion of patients. CT undertaken within 6 hours (with expertise of a neuroradiologist or radiologist who routinely interprets brain images) is highly accurate and likely to be sufficient to rule out SAH; CT beyond 6 hours is much less sensitive. The CT–LP pathway is highly sensitive for detecting SAH and some alternative diagnoses, although LP results in some false positive results.All data relevant to the study are included in the article or uploaded as supplementary information. Not applicable.