Advances in the early management of patients with head injury

Cerebral autoregulation and outcome in acute brain injury

The purpose of this study was to examine the relationship between Czosnyka and others' Pressure Reactivity Index (PRx) and neurologic outcome in patients with acute brain injury, including traumatic brain injury (TBI) and cerebrovascular pathology. PRx measures the correlation between arterial blood pressure and intracranial pressure waves and may reflect cerebral autoregulation in response to blood pressure changes. A negative PRx reflects intact cerebrovascular response, whereas a positive PRx reflects impaired response. Positive PRx has been shown to correlate with poorer outcome in individuals with TBI, but these findings have not been confirmed by replication in other studies, nor have PRx values been reported for individuals with cerebrovascular pathology. In this study, PRx was determined in 52 patients with TBI (n = 27) or cerebrovascular pathology (n = 25). Hierarchical linear regression was used to evaluate the contribution of PRx to outcome, controlling for age and Glasgow Coma Scale score. Analysis of all subjects together did not support the previously reported relationship between PRx and outcome. However, for those with TBI, positive PRx was a significant predictor of negative outcome (P = 0.03). For those with cerebrovascular pathology, the effect was not significant (P = 0.10) and was in the opposite direction. For individuals with TBI, PRx may provide useful information related to cerebral autoregulation that is predictive of outcome. The meaning of PRx in individuals with cerebrovascular pathology is unclear, and further study is needed to examine the paradoxical findings observed.

Management of increased intracranial pressure: a review for clinicians

Emergency physicians are frequently confronted with head-injured patients, many of whom have intracranial hypertension. Since direct correlations have been reported between increased intracranial pressure (ICP) and adverse outcome, it is important to rapidly identify and treat these patients. Furthermore, since the actual brain damage that occurs at the time of injury cannot be modified, the maximization of neurological recovery depends upon minimizing secondary insults to the brain, most notably preventing hypotension and hypoxemia. Volume resuscitation to maintain an adequate mean arterial pressure, airway control, and sedation and analgesia to prevent surges in ICP remain the cornerstone of early management. These principles and the emergency department management of the head-injured patient are reviewed in this paper.

Standardized management of intracranial pressure: a preliminary clinical trial

OBJECTIVE

To test a standardized protocol for management of intracranial pressure (ICP) after severe head injury (i.e., traumatic brain injury), consistent with published guidelines.

METHODS

We compared prospective use of a standardized protocol for ICP management in 12 patients with severe head injuries and retrospective ICP management using preprinted hospital orders in combination with ad hoc physician orders in 12 historical control patients with severe head injuries. With the standardized protocol, flow-chart decision logic diagrams were applied at patient bedside by critical care practitioners, with nursing shift review.

RESULTS

ICP and its variation during the first 6 intensive care unit days was less for the standardized protocol- than for the preprinted order-managed group (p <0.001), indicating better process control with the standardized protocol. ICP exceeded 25 mm Hg for less time for the standardized protocol group (182 hours; 15+/-23 hours/patient) than for prescribed order group (429 hours; 36+/-28 hours/patient) (p = 0.03). On average, ICP exceeded 20 mm Hg for 2.3 days for the standardized protocol-managed group and for 4.7 days for the prescribed order-managed group. Cerebral perfusion pressure was significantly greater and its variation less for the standardized protocol- than for the preprinted order-managed group. Fewer interventions were made for ICP management for the standardized protocol- than for the preprinted order-managed patients (601 vs. 876), suggesting more effective nursing time using the standardized protocol.

CONCLUSION

ICP management was more consistent, and intracranial hypertension was better controlled, in patients managed according to a standardized, data-driven protocol for escalation and weaning of therapies in response to immediate patient needs. We recommend computerized implementation and a randomized clinical trial to compare the protocol with prescribed orders.