Beta-2 receptor antagonists for acute traumatic brain injury

Ker K, Blackhall K

Summary

Beta-2 receptor antagonists for traumatic brain injury

Traumatic brain injury (TBI) is a leading cause of death and disability worldwide. Not all damage to the brain occurs at the moment of injury. The injury sustained at the moment of impact (primary brain injury) initiates a sequence of mechanisms which cause further brain damage (secondary brain injury).

One consequence of the mechanisms triggered by primary injury is the accumulation of fluid within the brain. This condition is known as cerebral oedema, and leads to raised intracranial pressure (pressure within the skull) which contributes to secondary brain injury.

The use of a group of drugs known as beta-2 receptor antagonists are being investigated as a potential treatment for TBI. It is proposed that they can inhibit the mechanism which causes cerebral oedema and therefore prevent the elevation of intracranial pressure and subsequent brain damage.

The authors of this review searched for all randomised controlled trials of the effects of beta-2 receptor antagonist on mortality and disability in traumatically brain injured patients. The authors found three trials involving 178 patients. The overall effect estimates suggest that beta-2 receptor antagonists may reduce mortality and disability compared to the control group, but the findings are consistent with the play of chance. The findings indicate that there is no reliable evidence to support the use of beta-2 receptor antagonists for TBI.

Beta-2 receptor antagonists are not presently registered for use in patients. Because the effects of beta-2 receptor antagonists on mortality and disability are yet to be reliably ascertained, they should not be used outside the context of well conducted trials. The findings of the ongoing BRAIN trial will enhance the knowledge of this area; the results will be incorporated into this review when released.