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).
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.
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).
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.
Abbreviations used in this paper: CPP = cerebral perfusion pressure; FiO2 = fraction of inspired oxygen; GCS = Glasgow Coma Scale; GOS = Glasgow Outcome Scale; HUP = Hospital of the University of Pennsylvania; ICP = intracranial pressure; ICU = intensive care unit; ISS = Injury Severity Score; LOS = length of stay; PbtO2 = partial pressure of brain tissue O2; SaO2 = arterial O2 saturation; TBI = traumatic brain injury.
Brain Trauma Foundation: American Association of Neurological Surgeons, Congress of Neurological Surgeons, Joint Section on Neurotrauma and Critical Care, AANS/CNS, et al: Guidelines for the management of severe traumatic brain injury. J Neurotrauma24:1 Suppl2007
Brain Trauma Foundation: American Association of Neurological Surgeons, Congress of Neurological Surgeons, Joint Section on Neurotrauma and Critical Care, AANS/CNS, Bratton SL, et al: Guidelines for the management of severe traumatic brain injury. X. Brain oxygen monitoring and thresholds. J Neurotrauma24:1 SupplS65–S702007
EdwardsPArangoMBalicaLCottinghamREl-SayedHFarrellB: Final results of MRC CRASH, a randomised placebo-controlled trial of intravenous corticosteroid in adults with head injury-outcomes at 6 months. Lancet365:1957–19592005
ElfKNilssonPRonne-EngströmEHowellsTEnbladP: Cerebral perfusion pressure between 50 and 60 mm Hg may be beneficial in head-injured patients: a computerized secondary insult monitoring study. Neurosurgery56:962–9712005
MaasAIMurrayGHenneyHIIIKassemNLegrandVMangelusM: Efficacy and safety of dexanabinol in severe traumatic brain injury: results of a phase III randomised, placebo-controlled, clinical trial. Lancet Neurol5:38–452006
RobertsISchierhoutGPAldersonP: Absence of evidence for the effectiveness of five interventions routinely used in the intensive care management of severe head injury: a systematic review. J Neurol Neurosurg Psychiatry65:729–7331998
SahuquilloJAmorosSSantosAPocaMAPanzardoHDomínguezL: Does an increase in cerebral perfusion pressure always mean a better oxygenated brain? A study in head-injured patients. Acta Neurochir Suppl76:457–4622000
StiefelMFSpiottaAGraciasVHGaruffeAMGuillamondeguiOMaloney-WilenskyE: Reduced mortality rate in patients with severe traumatic brain injury treated with brain tissue oxygen monitoring. J Neurosurg103:805–8112005
ToliasCMReinertMSeilerRGilmanCScharfABullockMR: Normobaric hyperoxia—induced improvement in cerebral metabolism and reduction in intracranial pressure in patients with severe head injury: a prospective historical cohort-matched study. J Neurosurg101:435–4442004
VespaPMO'PhelanKMcArthurDMillerCEliseoMHirtD: Pericontusional brain tissue exhibits persistent elevation of lactate/pyruvate ratio independent of cerebral perfusion pressure. Crit Care Med35:1153–11602007