Diagnostic test utilization in the emergency department for alert headache patients with possible subarachnoid hemorrhage

Abstract

Objectives: This study evaluated the incidence of subarachnoid hemorrhage (SAH) and the use of computed tomography (CT) and lumbar puncture (LP) in a cohort of emergency department (ED) patients with acute headache. Methods: Health records from a tertiary care ED were used to identify all patients over 15 years of age who presented with headache over a 10-month period. Patients were excluded if they had been referred with confirmed SAH or if they had recurrent headache, head trauma, decreased level of consciousness or new neurologic deficits. Outcome measures included ED diagnosis, use of CT or LP, and ED length of stay. Analysis included descriptive statistics, 95% confidence intervals (CIs) and analysis of variance for length of stay. Results: The mean age of the 891 patients was 41.9 years. Ten (1.1%) of the patients had SAH, 313 (35.1%) underwent CT, and 85 (9.5%) underwent LP. Only 9 (2.9%) of the CT scans and 2 (2.4%) of the LPs were positive for SAH. Of the 296 patients with normal CT results, 232 (78.4%) did not undergo subsequent LP. The mean length of stay was 4.0 hours (95% CI, 3.8-4.1) if no diagnostic testing was performed, 5.0 hours (95% CI, 4.7-5.4) if CT was performed and 7.1 hours (95% CI, 6.3-7.9) if LP was performed (p = 0.001). Conclusions: Diagnostic testing was associated with substantially prolonged lengths of stay. CT and LP had low diagnostic yields, which suggests the need for a clinical decision rule to rule out SAH in ED patients with acute headache. RÉSUMÉ Objectifs : La présente étude a évalué l'incidence des hémorragies sous-arachnoïdiennes (HSA) et le recours à la tomodensitométrie et à la ponction lombaire auprès d'une cohorte de patients reçus à l'urgence pour un mal de tête sévère. Méthodes : Les dossiers de santé provenant d'un département d'urgence (DU) de soins tertiaires furent utilisés pour identifier tous les patients âgés de plus de 15 ans ayant consulté pour un mal de tête sur une période de dix mois. Les patients furent exclus s'ils avaient été envoyés à l'urgence avec un diagnostic confirmé de HSA ou si leurs maux de tête étaient récurrents, s'ils étaient atteints d'un traumatisme crânien, d'une diminution de leur état de conscience ou de nouveaux dé-ficits neurologiques. Les mesures du résultat comprenaient le diagnostic au DU, le recours à la tomodensitométrie ou à la ponction lombaire et la durée du séjour au DU. L'analyse comprenait des statistiques descriptives, des intervalles de confiance (IC) à 95 % et l'analyse de la variance pour la durée du séjour.

Validation of the Ottawa Subarachnoid Hemorrhage Rule in patients with acute headache

“…[1][2][3][4] Although the decision to order neuroimaging in a patient with decreased level of consciousness or new neurologic deficits is relatively obvious, half of all patients with subarachnoid hemorrhage are alert and neurologically intact at first presentation. 5 Making a decison to send these patients for imaging tests is difficult, because timely diagnosis and treatment result in substantially better outcomes if subarachnoid hemorrhage is the cause of the headache.…”

Lumbar punctures: use and diagnostic efficiency in emergency medical departments

“…Considering published literature data, only few surveys studied the use and the diagnostic efficiency of LP in the EMD [1, 5, 8, 9]. Furthermore, none of the published studies used French populations.…”

“…Some findings [1] would appear to suggest that the examination of cerebrospinal fluids (CSF) in the EMD may not always be necessary and that some CSF tests may be excessive. Considering SAH and GBS, while these diseases are infrequently supported by LP results in the EMD [5, 9], missed diagnoses of SAH in the EMD have been reported [11]. Hence, there is a need for further investigations to explore the use and the efficiency of LP performed in the EMD.…”

Attitudes and Judgment of Emergency Physicians in the Management of Patients with Acute Headache

“…Without such guidelines, patients are often inefficiently tested, often in the direction of overtesting, thus contributing to increased length of stay in the ED. 12 We suspected that trained emergency physicians (EPs) could identify patients at low risk, prior to conducting diagnostic tests to rule out SAH; however, to the best of our knowledge, there have been no previous studies to confirm this hypothesis. Hence, it is not currently known how well physicians predict the likelihood of SAH for patients with an acute headache and normal results on neurologic examination.…”