Brain tissue oxygen-directed management and outcome in patients with severe traumatic brain injury: Clinical article

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 PbtO ₂-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 (PbtO ₂ < 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.