Severe traumatic brain injury (TBI) is associated with sympathetic hyperactivity resulting in catecholamine excess, abnormal heart rate variability, agitation and sympathetic storms, deep white matter changes, and poor neuropsychological outcomes. Notably, persistent sympathetic hyperactivity after TBI results in higher days of mechanical ventilation and longer intensive care unit (ICU) length of stay (LOS). While there are data describing limited portions of this response, the full spectrum of sympathetic hyperactivity after severe TBI has not been systemically described or methodically intervened upon.
We will perform a double-blinded, randomized, placebo-controlled pilot trial in a 100 patient cohort in which one group will receive centrally acting sympatholytic drugs, propranolol and clonidine, and the other group, placebo, within 48 hours of severe TBI. The length of therapy will be 7 days.
The primary question studied is whether ventilator-free days will be increased after therapy.
Secondary endpoints include plasma and urine catecholamine levels, heart rate and blood pressure variability, responses to autonomic cold pressor testing, assessments of coma, sedation, and agitation, sedative requirements, analgesic use, antipsychotic medication use, coma-free days, ventilator-free days, Intensive Care Unit (ICU) length of stay, and survival. Also, neuropsychological outcomes will be measured at ICU discharge, 3 months, and 12 months.
Interim Analysis: At approximately 50% targeted accrual, n=46 randomized subjects, an interim analysis will be performed with A Priori (planned) futility and efficacy rules, which are DSMB and IRB approved.
