The effectiveness of lumbar puncture in the evaluation of delirium and fever in the hospitalized elderly.

OBJECTIVE

To determine the value of the cerebrospinal fluid examination in the evaluation of hospitalized; elderly patients with delirium and fever.

DESIGN

A retrospective case series of consecutive events during a 15-month period.

SETTING

Tertiary care center.

PARTICIPANTS

Elderly patients admitted to the University of Cincinnati (Ohio) Hospital between July 1, 1988, and October 1, 1989, who had a lumbar puncture and cerebrospinal fluid evaluation to evaluate fever and mental status changes.

MAIN OUTCOME MEASURES: Primary intracranial causes and the clinical characteristics of delirium and fever.

RESULTS

Eighty-one hospital admissions were reviewed. Fifty-seven (70%) of the lumbar punctures were performed as part of the admitting workup, and the remaining 24 (30%) were performed during the hospitalization. Eighty of the 81 cerebrospinal fluid cultures were negative for bacterial growth. The primary origins for fever and delirium included urinary tract infections (25%), pneumonia (22%), viral causes (17%), and metabolic causes/dehydration (14%). One case of bacterial meningitis was diagnosed in an alcoholic, 73-year-old man who was unresponsive in the emergency department. One case of presumed aseptic meningitis was diagnosed in a 65-year-old man who presented with fever and headaches and a blood pressure of 230/100 mm Hg.

CONCLUSIONS

Most hospitalized, older patients with fever and delirium have primary causes of the confusion outside the central nervous system and may not require a routine evaluation of their cerebrospinal fluid.