An Observational Study of 2,248 Patients Presenting With Headache, Suggestive of Subarachnoid Hemorrhage, Who Received Lumbar Punctures Following Normal Computed Tomography of the Head

Acad Emerg Med. 2015 Nov;22(11):1267-73. doi: 10.1111/acem.12811. Epub 2015 Oct 19.

Abstract

Objectives: The objective was to determine the incidence of subarachnoid hemorrhage (SAH) diagnosed by lumbar puncture (LP) when the head computed tomography (CT) was reported as demonstrating no subarachnoid blood.

Methods: Data were obtained on patients who received LP to diagnose or exclude SAH attending six hospitals over 5 years. Subsequent investigations and outcomes were reviewed in all patients with LPs that did not exclude SAH.

Results: A total of 2,248 patients were included. A total of 1,898 LPs were suitable for biochemical analysis, of which 92 (4.8%) were positive for blood, suggesting SAH; 1,507 (79.4%) were negative; and 299 (15.6%) were inconclusive. Of the 92 patients with positive cerebrospinal fluid analysis, eight patients (0.4%) had aneurysms on further imaging, and one had a carotid cavernous fistula.

Conclusions: In patients presenting to the emergency department with acute severe headache, LP to diagnose or exclude SAH after negative head CT has a very low diagnostic yield, due to low prevalence of the disease and uninterpretable or inconclusive samples. A clinical decision rule may improve diagnostic yield by selecting patients requiring further evaluation with LP following nondiagnostic or normal noncontrast CT brain imaging.

Publication types

  • Multicenter Study
  • Observational Study

MeSH terms

  • Adult
  • Diagnosis, Differential
  • Emergency Service, Hospital / statistics & numerical data*
  • False Negative Reactions
  • Female
  • Headache / etiology*
  • Humans
  • Incidence
  • Male
  • Middle Aged
  • Prevalence
  • Retrospective Studies
  • Spinal Puncture / statistics & numerical data*
  • Subarachnoid Hemorrhage / diagnosis*
  • Subarachnoid Hemorrhage / diagnostic imaging*
  • Tomography, X-Ray Computed