Efficacy of subcutaneous morphine patient controlled analgesia compared to intravenous morphine patient controlled analgesia in cesarean section

Abstract

Background: Cesarean section causes moderate to severe pain in the first 48 hours postoperatively, thus requiring an adequate perioperative pain management, as of the mother can be quickly discharged and immediately can perform daily activities after surgery such as breastfeeding and nurse the baby. Objective: To determine the efficacy of subcutaneous morphine patient controlled analgesia (SC-PCA) in lowering VAS (visual analogue score), total morphine consumption and postoperative side effect of cesarean section compared with intravenous morphine patient controlled analgesia (IV-PCA). Methods: This study is an experimental clinical trial using consecutive sampling technique. Sixty-four subjects were allocated into two groups of PCA morphine subcutaneously (SC-PCA) and the group PCA morphine intravenously (IV-PCA), each consisting of 32 subjects using permuted block randomization. Morphine concentration was 5 mg/ml (group SC-PCA) or the concentration of 1mg/ml (group IV-PCA). Both groups were then analyzed for VAS ratings, total morphine consumption, and adverse effects, postoperatively at 4th, 8th, and 24th hour. Statistic analysis using repeated ANOVA test and t-test with p <0.05 considered significant. Result: Morphine consumption in IV-PCA group showed lower than SC-PCA (9.41 mg vs 4,9mg) p <0.001 24 at 24 hours postoperatively. The resting VAS at 4th hours significantly lower in IV-PCA group (1.06 ± 0.71 vs 0.81 ± 1.40, p=0.029) and at 8th hours (1.03 ± 0.59 vs 0.94 ± 0,9, p=0.048). The moving VAS at 4th hours significant lower in IV-PCA group (2.31 ± 0.47 vs 1.45 ± 2.06, p=0.019) but the resting or moving VAS are not different clinically. Side effects of nausea and vomiting are more common in IV-PCA group. We conclude that SC-PCA provides analgesia more effective and decreases side effects in patients undergo cesarean section with spinal anesthesia.