RESUMEN
BACKGROUND: Most women experience moderate to severe pain during labour and delivery, often requiring some form of pharmacologic analgesia. The lack of proper psychological preparation combined with fear and anxiety can greatly enhance the patient's sensitivity to pain and further add to the discomfort. Skillfully conducted obstetric analgesia, in addition to relieving pain and anxiety, may benefit the mother by increasing self esteem and improving bonding with the baby. OBJECTIVE: To assess and compare the satisfaction and efficacy of two regimens of single-shot spinal blocks for the relief of labor pain in women who present in active phase of labour. DESIGN: A prospective randomised single-blind observational study SETTING: Labour ward of Kenyatta National Hospital, Nairobi. SUBJECTS: All consenting primiparous women presenting in active phase of labor with uncomplicated singleton pregnancy at term (> 37 weeks) and in cephalic presentation, who reported a > 70 mm VAS (Visual Analog Scale) pain score at cervical dilatation ≥ 5 cm at the time of request for labour analgesia. RESULTS: Effective labour analgesia lasting up to 120 minutes was observed in the fentanyl-bupivacaine group but with high incidence of breakthrough pain. The fentanyl-bupivacaine-morphine group had labour analgesia lasting up to 180 minutes or even more with a lower incidence of breakthrough pain. The one-minute and five- minute Apgar scores in the morphine group were significantly lower (p = 0.026 and 0.044 respectively) than in the fentanyl group but the difference in neonatal outcome had no clinical significance, and there were no significant differences in adverse effects, sensory levels, and motor power between the two groups. CONCLUSION: Effective analgesia for about 120 minutes was observed in the fentanyl-bupivacaine group with high incidence of breakthrough pain while the fentanyl-bupivacaine-morphine group had labour analgesia prolonged up to more than three hours. The difference in fetal outcome had no clinical significance for the morphine group, and there were no significant difference in adverse effect, sensory levels, and motorpowerbetween the two groups. These findings show that intrathecal analgesia is safe and the use of the combination of fentanyl-bupivacaine-morphine gives adequate and safe analgesia during labour and delivery.