Mortality is reduced for heart rate 80 to 89 after traumatic brain injury

Background: Increasing data indicate treatment with beta blockers might improve survival after traumatic brain injury (TBI); the optimal heart rate (HR) range for these patients is unknown. To guide treatment, admission HR in moderate to severe TBI patients was analyzed to determine if a specific range is associated with decreased mortality.

Methods: The Los Angeles County Trauma System Database, consisting of five Level I and 8 Level II trauma centers, was queried for all injured patients admitted between 1998 and 2005 (n = 147,788). Isolated moderate to severe TBI patients (head abbreviated injury score > or = 3) were then identified. Demographics and outcomes were compared at various admission HR subgroups (<50, 50-59, 60-69, 70-79, 80-89, 90-99, 100-109, > or =110). Logistic regression was then performed to determine predictors of mortality.

Results: After exclusions, a total of 11,977 isolated moderate to severe isolated TBI patients were analyzed, overall mortality was 11.5% with a trend toward lowest mortality at HR 80 to 89 (7.3%). Each HR subgroup had a significantly increased unadjusted odds ratio for mortality compared with HR 80 to 89, except HR 90 to 99 (OR 1.2, CI 1.0-1.5) and HR 100 to 109 (OR 1.2, CI 1.0-1.5). In multivariable logistic regression analysis, HR <50, 50-59, 60-69, and > or =110 were independent predictors for increased mortality compared with HR 80-89.

Conclusion: After isolated moderate to severe TBI, HR <50, 50-59, 60-69, and > or =110 were independent predictors of increased mortality. HR outside the range 70-109 could serve as a marker for aggressive resuscitation. As mortality increased significantly with HR: <50 (AOR 4.70), 50-59 (AOR 2.21), and 60-69 (AOR 1.63), our findings recommend avoiding HR < 70 in patients with moderate to severe TBI.