Calcium channel blockers for acute traumatic brain injury.

BACKGROUND: Acute traumatic brain injury is a major cause of death and disability. Calcium channel blockers (calcium antagonists) have been used in an attempt to prevent cerebral vasospasm after injury, maintain blood flow to the brain, and so prevent further damage. OBJECTIVES: To estimate the effects of calcium channel blockers in patients with acute traumatic brain injury, and in a subgroup of brain injury patients with traumatic subarachnoid haemorrhage. SEARCH STRATEGY: Handsearching and electronic searching for randomised controlled trials. SELECTION CRITERIA: Randomised controlled trials in patients with all levels of severity of clinically diagnosed acute traumatic brain injury. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed the identified studies for eligibility and extracted data from each study. Summary odds ratios were calculated using the Mantel-Haenszel method. MAIN RESULTS: Six RCTs were identified as eligible for inclusion in the systematic review. The effect of calcium channel blockers on the risk of death was reported in five of the RCTs. The pooled odds ratio (OR) for the five studies was 0.91 (95% confidence interval [95%CI] 0.70-1.17). For the four RCTs that reported death and severe disability (unfavourable outcome), the pooled odds ratio was 0.85 (95%CI 0.68-1.07). In the two RCTs which reported the risk of death in a subgroup of traumatic subarachnoid haemorrhage patients, the pooled odds ratio was 0.59 (95%CI 0.37-0.94). Three RCTs reported death and severe disability as an outcome in this subgroup, and the pooled odds ratio was 0.67 (95%CI 0.46-0.98). REVIEWER'S CONCLUSIONS: This systematic review of randomised controlled trials of calcium channel blockers in acute traumatic head injury patients shows that considerable uncertainty remains over their effects. The effect of nimodipine in a subgroup of brain injury patients with subarachnoid haemorrhage shows a beneficial effect, though the increase in adverse reactions suffered by the intervention group may mean that the drug is harmful for some patients.