Brain tissue oxygen–directed management and outcome in patients with severe traumatic brain injury

Object The object of this study was to determine whether brain tissue oxygen (PbtO2)–based therapy or intracranial pressure (ICP)/cerebral perfusion pressure (CPP)–based therapy is associated with improved patient outcome after severe traumatic brain injury (TBI). Methods Seventy patients with severe TBI (postresuscitation GCS score ≤ 8), admitted to a neurosurgical intensive care unit at a university-based Level I trauma center and tertiary care hospital and managed with an ICP and PbtO2 monitor (mean age 40 ± 19 years [SD]) were compared with 53 historical controls who received only an ICP monitor (mean age 43 ± 18 years). Therapy for both patient groups was aimed to maintain ICP < 20 mm Hg and CPP > 60 mm Hg. Patients with PbtO2 monitors also had therapy to maintain PbtO2 > 20 mm Hg. Results Data were obtained from 12,148 hours of continuous ICP monitoring and 6,816 hours of continuous PbtO2 monitoring. The mean daily ICP and CPP and the frequency of elevated ICP (> 20 mm Hg) or suboptimal CPP (< 60 mm Hg) episodes were similar in each group. The mortality rate was significantly lower in patients who received PbtO2-directed care (25.7%) than in those who received conventional ICP and CPP–based therapy (45.3%, p < 0.05). Overall, 40% of patients receiving ICP/CPP–guided management and 64.3% of those receiving PbtO2–guided management had a favorable short-term outcome (p = 0.01). Among patients who received PbtO2-directed therapy, mortality was associated with lower mean daily PbtO2 (p < 0.05), longer durations of compromised brain oxygen (PbtO2 < 20 mm Hg, p = 0.013) and brain hypoxia (PbtO2 < 15 mm Hg, p = 0.001), more episodes and a longer cumulative duration of compromised PbtO2 (p < 0.001), and less successful treatment of compromised PbtO2 (p = 0.03). Conclusions These results suggest that PbtO2-based therapy, particularly when compromised PbtO2 can be corrected, may be associated with reduced patient mortality and improved patient outcome after severe TBI.