The value of lumbar puncture in the evaluation of critically ill, non-immunosuppressed, surgical patients: a retrospective analysis of 70 cases

Objective: To evaluate the diagnostic value of lumbar puncture (LP) in surgical intensive care unit (SICU) patients. Design: Retrospective chart review. Setting: Surgical intensive care unit at a major tertiary care medical center. Patients: All patients admitted to the SICU during the period 1987–1995 who had a lumbar puncture, excluding those with a history of recent head trauma or a neurosurgical procedure. Measurements: Cerebral spinal fluid (CSF) results, indication for lumbar puncture, admitting service, length of ICU stay, presence of fever and use of antibiotics. Results: Of 7,555 admissions to the SICU over the period 1987–1995, 204 patients underwent LP during the hospital admission. Four charts could not be located and 75 patients underwent LP in locations other than the SICU. Of the remaining 125 cases, 55 carried a neurosurgical diagnosis and 70 had non-neurosurgical problems. Fifty-three (75 %) of the patients had received antibiotics prior to the procedure. Among the 70 cases without a primary neurosurgical diagnosis, LP was performed to rule out infective meningitis suggested by fever and mental status changes (30 patients), mental status changes alone (7 patients), systemic illness with fever and/or mental status changes (10 patients), seizures (10 patients), meningismus (+/− fever, 4 patients), or a combination of neurological findings (8 patients). There were no cases in which meningitis was positively diagnosed. Medical management was altered in only two patients based upon the results obtained by LP. Conclusions: We conclude that LP in SICU patients without a recent history of head trauma or a neurosurgical operation is a low yield procedure, especially for the diagnosis of bacterial meningitis. Received: 10 September 1996 Accepted: 6 May 1997