Comparison among subarachnoid opioid mix for cesarean section An observational study

Abstract

Introduction Classically, the local anesthetic (LA) has been combined with one lipophilic and another hydrophilic opioid for neuraxial anesthesia in cesarean section. In Colombia, the practice has been the use of morphine hydrochloride with fentanyl, but the occasional shortage of the former triggered an interest in new options. In response to the shortage of morphine in 2017-2018, a contingency plan was developed at the SES Hospital in Caldas, prefilling syringes at the hospital compounding central, with: bupivacaine, morphine and fentanyl (BMF); bupivacaine, fentanyl and hydromorphone (BFH); and bupivacaine and hydromorphone (BH). Hydromorphone has a rapid onset of action, long-lasting effect and is indicated for spinal administration in the safety data sheet; therefore, the advantages of adding fentanyl to this mix are questionable. Objective To compare the clinical analgesic efficacy at the time of the incision and during the first 12 hours after surgery. Methods An observational, analytical study was conducted, using the mixtures BMF, BFH and BH in patients receiving subarachnoid anesthesia for cesarean section. Pain was assessed at the time of the incision, as well as any adverse effects and the pain visual analogue scale over the following 12 hours. Results Of the 71 patients participating in the study, 40.9 % received BMF; 22.5 %, BFH; and 36.6 %, BH. None of the patients experienced pain at the time of the incision. There was no difference in terms of adverse effects among the three groups. The mean difference in the visual analogue scale (VAS) for postoperative pain at 3, 6 and 12 hours was lower in the groups in which hydromorphone was used. Conclusion BFH and BH combinations are comparable to the original preparation in terms of adverse effects, with the advantage of being more effective in controlling postoperative pain.