Improving the Outcome of Severe TBI
TBI is the leading cause of death and disability under age 45 in Australia. We are undertaking 2 studies at the Alfred Hospital to intervene early post injury.
1. To determine the effect of early decompressive craniectomy (DECRA) on adult TBI patients with diffuse brain swelling and refractory intracranial hypertension on outcome.
Severe TBIs with refractory brain swelling have poor outcomes. DECRA lowers ICP but is often performed late. We are studying the impact of early DECRA on clinical outcome using a RCT. Methods: Eligible patients have severe TBI , GCS<9, diffuse injury on CT, <72 hrs after injury, 16-60 yrs, ideally a ventricular drain and refractory ICP. Patients are randomised to DECRA or intensive medical management. Late salvage DECRA is not excluded. A large bifrontal craniectomy is performed. Outcomes are assessed by GOS-E scores (6 & 12 months) and mortality. Plan is to recruit 210 patients by end of 2006. Progress: In pilot study at Alfred Feb-July 2003, 1 patient/month was enrolled. There are now 16 participating centres in Australia and NZ.
2. Intensive monitoring following severe TBI. We have developed treatment algorithms based on brain tissue oxygen monitoring and mixed jugular venous saturation monitoring, ICP, Cerebral Perfusion Pressure (CPP), and competence of cerebral autoregulation based on the PRX index. Cerebral blood flow is imaged using CT perfusion scans. Cerebral microdialysis has been added to correlate brain metabolism with oxygen and physiological monitoring. We also monitor cerebral adenosine levels and correlate these with cerebral autoregulation and CBF and CSF adenosine. Cerebral oedema following TBI is difficult to treat and is a cause of significant morbidity. We are monitoring cerebral atrial natriuretic peptide (ANP) using microdialysis and correlating this with degree of cerebral swelling as this peptide has been implicated in the pathogenesis of cerebral oedema following TBI. Progress of this work will be presented.