Cerebrospinal Fluid Cultures in Traumatic Brain Injury: Is It Worth It? A Two-Center Study

Patients with traumatic brain injury (TBI) frequently develop leukocytosis, fever, and tachycardia that may lead to extensive medical investigations to rule out an infectious process. Cerebrospinal fluid (CSF) is often acquired during this workup, however, the utility of this practice has not been studied previously. We hypothesized that CSF cultures would unlikely yield positive results in patients with TBI. A retrospective review was conducted of all patients with TBI admitted to two level 1 trauma centers at urban, academic institutions from January 2009 to December 2016. Data collected included patient demographics, presenting Glasgow Coma Score (GCS), injury profile, injury severity scores (ISS), regional abbreviated injury scale (AIS), hospital and intensive care unit (ICU) length of stay (LOS), ventilator days, and culture results. For purposes of the analysis, CSF cultures with Staphylococcus epidermidis, Staphylococcus aureus, or Candida underwent a chart review and were considered contaminates if indicated. There were 145 patients who had CSF cultures obtained with a median age of 39 years; 77.2% were male. The majority of patients presented after blunt trauma with median GCS of 6, head AIS of 4, and ISS of 25. These patients had prolonged median ICU and hospital stays at 13 and 22 days, respectively. Six (4.1%) CSF cultures demonstrated growth. Four (2.8%) were deemed contaminants, with two growing Staphylococcus epidermidis only, one with both Staphylococcus epidermidis and Staphylococcus aureus, and one with Candida. Two cultures (1.4%) were positive and grew Enterobacter cloacae. Of note, both patients had prior instrumentation with an external ventricular drain. Obtaining CSF cultures in patients with TBI is of low yield, especially in patients without prior external ventricular drain. Other sources of infectious etiologies should be considered in this patient population.