comparative study between analgesic effect of low-dose intravenous ketamine and intrathecal fentanyl with spinal anaesthesia for caesarean section

ABSTRACT

For comparing the analgesic effects of intrathecal fentanyl and low-dose intravenous ketamine as adjuvants to intrathecal bupivacaine for Caesarean section. Forty five elective Caesarean section patients were randomized into three groups. Spinal anaesthesia was performed with 15 mg hyperbaric bupivacaine in all groups. Ketamine [0.15 mgkg -1] or an equal volume of normal saline was given intravenously immediately after initiating spinal anaesthesia in ketamine and control group respectively. Infentanyl group, 10 micro g fentanyl was added to intrathecal bupivacaine. Arterial pressures, heart rate values, adverse effects, the first request for postoperative analgesia, visual analogue pain scores, total analgesic consumptions at 24 and 48 h were recorded in all patients. The time to first request for analgesia was significantly longer in the ketamine [197 min] and fentanyl [165 mm] groups compared to the control group [144 min]. Postoperative pain scores were significantly lower in the ketamine group than in both other groups. Although the analgesic requirements during first 24h were significantly lower in the ketamine group, there was no significant differences between the groups during the following 24 h Intravenous low-dose ketamine combined with intrathecal bupivacaine for Caesarean section provides longer lower postoperative analgesia and lower postoperative analgesic consumption than bupivacaine alone suggesting a pre-emptive effect