Comparison of intrathecal sufentanil and morphine in addition to bupivacaine for caesarean section under spinal anesthesia

Background; Co-administration of small dose of opioids with bupivacaine for spinal analgesia is advocated because of synergistic action between local anaesthetics and opioids, leading to reduction in doses, intraoperative discomfort and postoperative analgesic requirement. Aim: We compared the effects of intrathecal sufentanil with intrathecal morphine, when added to bupivacaine for caesarean sections. Method: Sixty ASA I and II parturients, undergoing caesarean section under spinal anaesthesia, were randomly allocated into three groups of 20 each to receive cither injection (inj.) bupivacaine 12mg (Group I), which was labelled as the control group; inj. bupavacaine 12mg + inj sufentanil 10mcg (Group II) or inj. bupavacaine 12 mg + morphine 0.2mg (Group III) in a double blind clinical trial. The parameters studied were the time of onset, sensory level of the block achieved, total duration of analgesia, any need of rescue analgesics, maternal side effects and foetal outcome.. Result: Mean duration of analgesia (hrs) was higher in group III as compared to group I and group II (15,9 +/- 0,96 VS. 1.95 +/- 0.55 and 5.83 +/- 0.39 respectively); total duration of analgesia was significantly longer with the use of sufentanil and morphine as compared to control (5.83 +/- 0.39 and 15.91 +/- 0.96 vs. 1,95 +/- 0.55), Onset of block was significantly faster with use of sufentanil in Group II (1.92 +/- 0.27) vs. Group I and II (4.64 +/- 0.28 and 4.50 +/- 0.22 respectively). Analgesia was significantly better with the use of opioids compared to control as no additional analgesic were required in both groups. Side effects with insignificant difference noted were hypotension, nausea, and shivering. However, vomiting had a higher incidence in Group I [8(40%) vs. 1(5%) and 6(30%)]; and the incidence of pruritis and somnolence was higher [6(30%)] in Group II as compared to Group III [2(10%) and 1(5%) respectively]. No adverse effects on foetus were seen with use of opioids and comparable Apgar scores were noted. Conclusion: Addition of small doses of sufentanil or morphine to intrathecal bupivacaine is suitable for use in caesarean section, providing rapid onset and prolonged analgesia but with some side effects like pruritis and somnolence.