Brain tissue oxygen monitoring for severe traumatic brain injury: the international multicentre randomised controlled BONANZA-GT study protocol.

Abstract

The management of severe traumatic brain injury (sTBI) in the intensive care unit (ICU) is focused on preventing secondary brain insults, by ensuring adequate cerebral perfusion, oxygenation and substrate delivery. Despite optimisation of intracranial pressure (ICP) and cerebral perfusion pressure (CPP) using evidence-based guidelines, brain tissue hypoxia can still occur and is strongly associated with adverse functional outcomes post sTBI. The Brain Oxygen Neuromonitoring in Australia and New Zealand Assessment - Global Trial (BONANZA-GT) is an international, two-arm, open-label, parallel group, randomised controlled trial comparing sTBI management incorporating early brain tissue oxygen (PbtO₂) monitoring and optimisation, with ICP/CPP-based management alone. A total of 860 adults admitted to participating institutions with non-penetrating sTBI and requiring insertion of an ICP monitor (as determined by the treating neurosurgeon) will be enrolled. The primary outcome is the proportion of patients with favourable neurological outcomes, as defined by a Glasgow Outcome Score-Extended (GOS-E) >4, at 6 months following injury. Key secondary outcomes include all-cause mortality at ICU discharge, hospital discharge, adverse events, as well as hospital and ICU length of stay and GOS-E at 12 months. The BONANZA-GT will determine whether a protocolised therapeutic strategy guided by continuous PbtO₂ monitoring in addition to ICP/CPP targets results in improved neurological outcomes when compared with standard care using ICP/CPP-guided management alone. Approval has been obtained from relevant ethics boards in every jurisdiction that is participating in the trial. Inclusion of adults who lack capacity for informed consent will be governed in accordance with the legal requirements of each participating site. Study findings will be presented at scientific meetings and disseminated via peer-review publications. Australian and New Zealand Clinical Trials Registry (ACTRN 12619001328167).