Calcium channel blockers for prevention of noise trauma in otologic surgery.

One hundred patients were tested prior to otologic ear surgery in a prospective, randomized, double-blind study to assess the perioperative efficiacy of a calcium channel blocker (diltiazem) in preventing acoustical trauma during middle ear surgery. The patients were randomly divided into a therapy group (diltiazem), and a control group (placebo). Bone conduction hearing thresholds were examined preoperatively and followed at 1 day and 3 months postoperatively. Frequency-dependent changes in postoperative bone conduction and the number of patients with various degrees of postoperative hearing loss in both groups were statistically analyzed. The results indicated only a small postoperative hearing loss after ear surgery in both groups. There was a tendency for better results in the therapy group but this was not found to be statistically significant. Despite favorable results in animal trials utilizing different kinds of noise with the prophylactic application of diltiazem, further studies in humans will be needed to determine the role of calcium antagonist drugs in the prophylaxis or treatment of acoustical trauma.