Can the extent of halothane debromination be predicted preoperatively?

In an attempt to predict the extent of halothane debromination, antipyrine metabolic clearance rate was measured preoperatively in 22 surgical patients, then correlated with percent hours of subsequent halothane exposure and postoperative serum bromide levels. There was a significant correlation (r = 0.78, p less than 0.001) between peak bromide level and anesthetic exposure but no correlation between peak bromide levels and antipyrine metabolic clearance rate. Thus, antipyrine is of no value for predicting the extent of halothane debromination. Mean peak bromide level 0.97 +/- 0.09 mM occurred on day 3 after anesthesia. This value is well below the psychoactive range. The data, therefore, also suggest that there is not a causal relationship between halothane biotransformation and the clinical syndrome of bromism.