Hemoglobin Area and Time Index Above 90 g/L are Associated with Improved 6-Month Functional Outcomes in Patients with Severe Traumatic Brain Injury.

PURPOSE: There is conflicting data on the relationship between anemia and outcomes in patients with traumatic brain injuries (TBI). The objective of this study was to determine if the proportion of time and area under the hemoglobin-time curve of ≥90 g/L are independently associated with 6-month functional outcomes. METHODS: Retrospective cohort study of 116 patients with a severe TBI who underwent invasive neuromonitoring between June 2006 and December 2013. Hemoglobin area (HAI) and time (HTI) indices were calculated by dividing the total area, or time, under the hemoglobin-time curve at 90 g/L or above by the total duration of monitoring. Multivariable log-binomial regression was used to model the association between HAI or HTI and 6 month favorable neurologic outcome (Glasgow Outcome Score 4 or 5). RESULTS: Patients had a mean age of 38 years (SD 16) with a median admission Glasgow Coma Scale of 6 (IQR 4-7). There were 1523 hemoglobin measurements and 523 monitoring days. Patients had a hemoglobin ≥90 g/L for a median of 70 % (IQR 37-100) of the time. Each 10 g/L increase in HAI (RR 1.23, 95 %CI 1.04-1.44, P = 0.011), and 10 % increase in HTI (1.10, 95 %CI 1.04-1.16, P < 0.001) were associated with improved neurologic outcome. Thirty-one patients (27 %) received a transfusion with the median pre-transfusion hemoglobin being 81 g/L (IQR 76-87). CONCLUSIONS: In patients with severe TBI, increased area under the curve and percentage of time that the hemoglobin concentration was ≥90 g/L, were associated with improved neurologic outcomes.

The safety of synthetic colloid in critically ill patients with severe traumatic brain injuries.

PURPOSE: Although 4% albumin is associated with increased mortality in patients with traumatic brain injury (TBI), evidence concerning the safety of synthetic colloids is lacking. We aimed to determine if there is an association between synthetic colloids and mortality in patients with severe TBI. MATERIALS AND METHODS: A retrospective cohort study of patients with severe TBI was conducted. Data were collected on all intravenous fluids administered during the first 14 days of admission. Multivariable Cox proportional hazards regression was used to model the association between daily cumulative pentastarch quintiles and mortality. RESULTS: Patients receiving pentastarch had higher Acute Physiology and Chronic Health II scores (23.9 vs 21.6, P < .01), frequency of craniotomy (42.5% vs 21.6%, P = .02), longer duration of intensive care unit stay (12 vs 4 days, P < .01), and mechanical ventilation (10 vs 3 days, P < .01). On unadjusted Cox regression, patients in the highest quintile of cumulative pentastarch administration had a higher rate of mortality compared with those receiving no colloid (hazard ratio, 3.8; 95% confidence interval, 1.2-12.4; P = .03). However, this relationship did not persist in the final multivariable model (hazard ratio 1.0; 95% confidence interval, 0.25-4.1; P = .98). CONCLUSION: There was no association between cumulative exposure to pentastarch and mortality in patients with severe TBI.