Decrease in white blood cell counts after thiopentone barbiturate therapy for refractory intracranial hypertension: A common complication

BACKGROUND: Leucopenia has been reported after induction of thiopentone barbiturate therapy for refractory intracranial hypertension. However, the incidence and characterisitics are not well described. AIMS: We performed a retrospective review to describe the incidence and characteristics of leucopenia after induction of thiopentone barbiturate therapy. SETTING AND DESIGN: Our centre is a national referral centre for neurotrauma and surgery in a tertiary medical institution. MATERIALS AND METHODS: We performed a retrospective review of all patients who received thiopentone barbiturate therapy for refractory intracranial hypertension during an 18 month period from January 2004 to June 2005 in our neurosurgical intensive care unit. STATISTICAL ANALYSIS USED: Statistical analysis was performed using SPSS version 15.0. All data are reported as mean ± standard deviation or median (interquartile range). The Chi square test was used to analyze categorical data and student t test done for comparison of means. For paired data, the paired t-test was used. RESULTS: Thirty eight (80.9%) out of 47 patients developed a decrease in white blood cell (WBC) count after induction of thiopentone barbiturate coma. The mean decrease in WBC from baseline to the nadir was 6.4 × 10(9)/L (P < 0.001) and occurred 57 (3-147) h after induction. The mean nadir WBC was 8.6 ± 3.6 × 10(9)/L. Three (6.4%) patients were leucopenic, with a WBC count of 2.8, 3.1, and 3.6 × 10(9)/L. None of them were neutropenic. We did not find an association between decrease in WBC count and clinical diagnosis of infection. We did not find any association between possible risk factors such as admission GCS, maximum ICP prior to induction of barbiturate coma, APACHE II score, total duration and dose of thiopentone given, and decrease in WBC count. CONCLUSIONS: Decrease in WBC count is common, while development of leucopenia is rare after thiopentone barbiturate coma. Regular monitoring of WBC counts is recommended.