Does evidence of reductive halothane biotransformation correlate with hepatic binding of metabolites in obese patients?

Covalent binding of fluorinated anesthetic metabolites was measured using intraoperative liver biopsies obtained from 48 morbidly obese patients randomly assigned to receive N₂O-O₂ combined with either fentanyl, enflurane, or halothane. No difference in binding was found between anesthetic groups. In addition, preoperative and postoperative levels of serum glutamic oxaloacetic transaminase (SGOT) and serum glutamic pyruvic transaminase (SGPT) did not differ among three groups of patients. However, hepatic organic fluoride binding significantly correlated with peak serum ionic fluoride in patients given halothane (p <0.001, r = 0.68). Thus, the fluorinated metabolites binding assay is a reliable index of reductive halothane metabolism. Possible application of this assay to aid in the diagnosis of postoperative liver dysfunction is suggested.