Continuous thoracic spinal anesthesia with local anesthetic plus midazolam and ketamine is superior to local anesthetic plus fentanyl in major abdominal surgery

Background: Limited studies have applied thoracic continuous spinal anesthesia in abdominal surgery, relying exclusively on opioids. This retrospective study analyzes 2 different schemes of thoracic continuous spinal anesthesia and postoperative analgesia in elderly patients undergoing major abdominal surgery. Methods: A total of 98 patients aged ≥ 75 years were divided into 2 groups. The control group (60 patients) received bupivacaine plus fentanyl, whereas the study group (38 patients) received bupivacaine plus ketamine and midazolam. Both received analogous postoperative continuous intrathecal analgesia. Several perioperative variables were evaluated. Results: Spinal anesthesia was performed without complications in all patients. Doses of noradrenaline administered, incidence of respiratory depression, need for intraoperative sedation, and time to first flatus were significantly reduced in the bupivacaine plus ketamine and midazolam group. Conclusion: In a population of frail, elderly patients, thoracic continuous spinal anesthesia with local anesthetic plus midazolam and ketamine was superior to local anesthetic plus fentanyl. In the group receiving local anesthetic plus midazolam and ketamine, the incidence of respiratory depression was reduced, and doses of norepinephrine and intraoperative sedating medications were lower. Intraoperative anesthesia and postoperative analgesia were similar in both groups.