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.