Résumé
Postoperative pain produces adverse physiologic effects with manifestations on multiple organ system. Techniques using a combination of local anesthetic as ropivacaine and opioids have proved to be the most satisfactory in the majority of parturients undergoing cesarean section, because of improved intraoperative comfort. The present study aimed to compare the postoperative analgesic properties of fentanyl and morphine in conjunction with ropivacaine when administrated at apparently optimum dosage. Forty fife female patients were randomly classified into 3 groups. Group I: It consists of 15 patients who received intrathecal ropivacaine 18 mg [2.5 ml] +lml saline 0.9%, all in total volume 3.5 ml. Group II: it consists of 15 patients who received intrathecal ropivacaine 18 mg [2.5 ml] + 300 micro g morphine [1ml], all in total volume 3.5 ml. Group III: it consists of 15 patients who received intrathecal ropivacaine 18 mg [2.5 ml] +20 micro g fentanyl [1ml], all in total volume 3.5 ml. Spinal anesthesia was done to each group by 22gauge pencil-point spinal needle, using midline approach at the level of inters pace L3-4. The study drug was injected at a rate of approximately 0.2ml /sec. maternal mean arterial blood pressure [base line and every 5 minutes until arterial blood pressure became stable then every 1 hour]. Assessment of the neonatal Apgar scores at 1 and 5 min after delivery. Assessment of the onset time to sensory block, maximum sensory level, and time to sensory recovery to L5 was done. Assessment of the motor block was done immediately after sensory block using modified Bromage scale. Also motor block time was recorded. Nausea and vomiting were assessed by ordinal scale. Sedation was assessed by sedation scale. Other complications e.g. respiratory complications and pruritis were recorded. Stability of blood pressure was observed in the three groups. The maximal height of sensory block was similar in the three groups [T2 to T3]. All patients developed complete motor block of lower extremities [Bromage scale, 3] after 3.64 +/- 0.41, 3.51 +/- 0.48 and 3.66 +/- 0.44 minutes in the control, fentanyl and morphine groups respectively. The time required for complete motor recovery was not significant between the three groups, which were ranged from 123.16 to 127.46 minutes. The overall quality of intraoperative analgesia as regarding the time of the first pain sensation, post-spinal injection, was significantly better in the fentanyl [207.32 +/- 24.29 minutes] and morphine [130.18 +/- 20.33 minutes] groups compared with the control group [101.67 +/- 7.56 minutes], [P< 0.05]. There were no patients either in the fentanyl or in the morphine group's required supplementary intraoperative analgesia compared with 3 patients in the control group [P< 0.05]. Regarding the neonatal Apgar score after 1 and 5 minutes, there were no different between the three groups. In the all neonates, the Apgar score was ranging between 8-10. As regard sedation score statistically significant difference between morphine and fentanyl groups and the control group was observed. Addition of both morphine and fentanyl to local anesthetics increased its analgesic efficacy. Morphine was superior to fentanyl as it produces long-term analgesia while fentanyl caused short-term analgesia. Fentanyl may be recommended as an efficient analgesic with less side effects than morphine when injected intrathecally. Both morphine and fentanyl had no effect on neonatal Apgar scores