Intra-operative natural sound decreases salivary amylase activity of patients undergoing inguinal hernia repair under epidural anesthesia

Background: The perioperative period is psychologically as well as physically stressful for patients. Although music and sound are known to reduce patients' psychological stress, a few previous studies showed an objective outcome of music. The aim of the present study was to evaluate the relaxing effect of music during epidural anesthesia, using patients' salivary amylase activity.
Methods: Thirty-two American Society of Anesthesiologists (ASA) I or II patients presenting for inguinal hernia repair under epidural anesthesia were randomly assigned to listen to sounds of a soft wind and a twitter (S group) or to have no sounds (N group). Patients' salivary amylase activity was evaluated on arrival to the operating room and at wound closure.
Results: Intra-operative music significantly decreased salivary amylase activity at wound closure in the S group and the activity at wound closure of the S group was significantly smaller than that of the N group.
Conclusion: Intra-operative natural sound significantly decreased salivary amylase activity of patients undergoing inguinal hernia repair under epidural anesthesia.