[Significance of phrenic nerve block in the anesthetic management of laparoscopic cholecystectomy].

The significance of phrenic nerve block was studied in the anesthetic management of laparoscopic cholecystectomy. Right phrenic nerve block with 1% mepivacaine 10 ml was performed after the patients were epidurally catheterized and anesthetized with isoflurane and nitrous oxide in oxygen. Intraoperative anesthetic requirement and postoperative shoulder pain incidence in patients with this block were compared with those in patients without block. Addition of the phrenic nerve block to general and epidural anesthesia did not reduce the intraoperative dosage of isoflurane, but it significantly prevented occurrence of postoperative right shoulder pain. It is known that phrenic nerve contains sensory element and that laparoscopic procedures of gall bladder elicit noxious stimuli which cannot be blocked by ordinary epidural anesthesia for abdominal surgery. Also, shoulder pain is said to be phrenic nerve-mediated referred pain. Our study suggests that blockade of these stimuli is effective in preventing postoperative event rather than intraoperative.