Decompressive craniectomy for elevated intracranial pressure and its effect on the cumulative ischemic burden and therapeutic intensity levels after severe traumatic brain injury

BACKGROUND Increased intracranial pressure (ICP) can cause brain ischemia and compromised brain oxygen (PbtO2 < or = 20 mm Hg) after severe traumatic brain injury (TBI). OBJECTIVE We examined whether decompressive craniectomy (DC) to treat elevated ICP reduces the cumulative ischemic burden (CIB) of the brain and therapeutic intensity level (TIL). METHODS Ten severe TBI patients (mean age, 31.4 +/- 14.2 years) who had continuous PbtO2 monitoring before and after delayed DC were retrospectively identified. Patients were managed according to the guidelines for the management of severe TBI. The CIB was measured as the total time spent between a PbtO2 of 15 to 20, 10 to 15, and 0 to 10 mm Hg. The TIL was calculated every 12 hours. Mixed-effects models were used to estimate changes associated with DC. RESULTS DC was performed on average 2.8 days after admission. DC was found to immediately reduce ICP (mean [SEM] decrease was 7.86 mm Hg [2.4 mm Hg]; P = .005). TIL, which was positively correlated with ICP (r = 0.46, P < or = .001), was reduced within 12 hours after surgery and continued to improve within the postsurgical monitoring period (P