Association between Blood Glucose Levels the Day after Targeted Temperature Initiation and Outcome in Traumatic Brain Injury: A Post-Hoc Analysis of the B-HYPO Study.

Abstract

We investigated associations between blood glucose levels and clinical outcomes in participants of the multi-center randomized controlled Brain-Hypothermia (B-HYPO) study. Patients with severe traumatic brain injury (TBI, Glasgow Coma Scale 4-8) were assigned to therapeutic hypothermia (TH, 32-34°C, n = 98) or fever control (35.5-37.0°C, n = 50) groups. TH patients were cooled as soon as possible for ≥72 h and rewarmed at a rate of <1°C/d. We recorded blood glucose (BG) levels on days 0, 1, and 3 after treatment initiation, and day 1 after rewarming. The Glasgow Outcome Scale was assessed at 6 months. Median BG levels decreased from day 0 to day 1 (163 vs. 132 mg/dL, p = 0.0062) in the fever control group. In contrast, a decrease was observed from day 1 to day 3 (157.5 vs. 126 mg/dL, p < 0.001) in the TH group. Day 1 BG was higher in the TH group compared with the fever control group (p = 0.0252). At day 0, BG levels were higher in non-survivors compared with survivors across all patients (p = 0.0035), the TH group (p = 0.0125), and the non-surgical group (p = 0.0236). Higher day 1 BG levels were observed in non-survivors compared with survivors across all patients (p = 0.0071), the fever control group (p = 0.0495), and the surgical group (p = 0.0364). In the TH group, the initial stress hyperglycemia was sustained the next day after TH induction. Day 1 BG predicted outcome in TBI patients with TH and fever control. Our findings indicate the significance of BG control particularly during TH treatment.