The role of head CT prior to lumbar puncture in patients with suspected meningitis in a Johannesburg emergency department
Date
2021
Authors
Cronje, Lana
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Abstract
Background: Significant considerations exist when establishing which patients require a computed tomography scan of the brain (CTB) prior to lumbar puncture for suspected meningitis. Over-scanning patients have numerous implications including increasing healthcare costs and emergency department (ED) length of stay. Data on the imaging practices of doctors working in South African EDs is limited as well as whether they are considering the Federation of Infectious Diseases Society of Southern Africa (FIDSSA) guidelines around this practice. Hitherto there is no consensus regarding which patients require a CTB and which should proceed to a lumbar puncture without one. Objectives: To describe current practices and the usefulness of the FIDSSA criteria relating to CTB prior to lumbar puncture and CTB results in patients with suspected meningitis in an academic, tertiary emergency department. Methods: A retrospective, descriptive chart review was conducted of 284 adult patients presenting to Charlotte Maxeke Johannesburg Academic Hospital ED who had a CTB prior to lumbar puncture for suspected meningitis between 1 November 2016 and 31 October 2018. Data analysed included patient demographics, indications for CTB, presence of FIDSSA criteria, laboratory findings and CTB results. Results: Two hundred and eighty-four patients with suspected meningitis who had a CTB scan prior to lumbar puncture were identified. Patients had a mean age of 39 years (range 18-81 years) and a male predominance (n= 157, 55%). HIV co-infection rates were 67%, the CD4 count was less than 200 in 47% of patients and cryptococcal meningitis was diagnosed on cerebrospinal fluid (CSF) analysis in 41% of subjects. Altered mental state (61%) was the most common indication for imaging, followed by headache (39%) and focal neurological deficit (31%). FIDSSA criteria for imaging were absent in 31% of patients. CTB scans revealed intracranial abnormalities in 121 patients (43%) and major findings which could preclude lumbar puncture in 32 (11%). Major abnormalities were found in 23 patients (16%) with FIDSSA criteria and 7 (8%) without. This association between the presence of FIDSSA criteria and major CTB scan abnormalities was not statistically significant (p=0.114). Conclusion: There is poor guideline adherence regarding CTB prior to lumbar puncture with consequential delays in appropriate treatment, diagnosis and increasing healthcare costs. However, the FIDSSA guidelines require prospective validation for use in an ED setting as the absence thereof may not identify major abnormalities in several patients
Description
A research report submitted to the Faculty of Health Sciences, University of Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Masters of Medicine in Emergency Medicine, 2021