Nitrous oxide does not impair hepatic function in young or old surgical patients

We investigated whether anesthesia including nitrous oxide (N2O) caused hepatic injury, and whether any adverse effect of N2O was affected by patient age. One hundred patients having total hip replacements were randomly assigned to a regimen that included or excluded N2O (50%-60%) during regional anesthesia supplemented with isoflurane and intravenous adjuvants. Using postoperative plasma levels of alanine aminotransferase, bilirubin, and alkaline phosphatase 1 and 3 days after surgery as indicators of hepatic impairment, we found no evidence that N2O causes hepatic injury in either young or old patients.