The Effect of Targeted Beta Blocker Use in Trauma Patients Admitted to the Intensive Care Unit

Beta-blockers are used to reduce heart rate (HR) and thereby reduce myocardial oxygen demand. Current guidelines include a recommendation for the use of beta-blockers titrated to a target HR of 60 to 70 beats per minute (bpm) in certain populations; however, the value of this intervention has not yet been studied in the trauma population. Our objective was to determine whether beta-blockers used to titrate heart rate to 60-70 bpm within the first 24 hours of intensive care unit (ICU) admission affect outcome in trauma patients. We retrospectively examined the trauma registry to identify patients admitted to the ICU of an urban level-I trauma center over the course of January to December 2013; medical records were further reviewed to identify those who received treatment with beta-blockers. Data was collected on patient demographics, maximum/minimum HR within 24 hours of admission, achievement of target HR (60-70 bpm), type of beta-blocker administered, length of stay (LOS), injury severity score (ISS), and survival to discharge. Patients were stratified into two groups based upon whether target HR was achieved at least once during the first 24 hours of ICU admission. Statistical analysis was performed using chi-square analysis or t-test as appropriate. A total of 208 patients, 65 females and 143 males with an average age of 59.3 ± 19.3 years, were included. The majority of patients (88.9%) were treated with metoprolol while the rest received atenolol, labetalol, or carvedilol. Eighty-six patients reached target HR on the first day of ICU admission. Heart rate ranged from 48 to 150 bpm; maximum HR was significantly lower in the target HR achieved group (82 ± 2.4 vs 99.9 ± 2.8 bpm, p<0.001). There was no significant difference between the amount of injury sustained by the target HR achieved (ISS 14.2 ± 1.9) and target HR not achieved (ISS 15.9 ± 1.9) groups. Achievement of target HR was associated with a shorter LOS (5.8 ± 1.3 d vs. 10.5 ± 2.3 d, p-value 0.002) and increased likelihood of survival (OR 5.02, 95%CI 1.67-15.2, p=0.004).