Background: Intrathecal adjutants can be used for regional anesthesia (RA) in cesarean section to improve its quality in terms of time and complications. Some previous studies focused on the effects of adding sufentanil and/or midazolam to bupivacaine and compared each with using bupivacaine alone. However, there has been no study to assess the effects of using sufentanil and midazolam in combination with bupivacaine.
Objectives: The aim of this study was to evaluate and compare properties (time of achievement/recovery of sensory/motor blocks; and time to request opium), complications (nausea, vomiting, shivering and hypotension), and neonatal first minute Apgar score with and without the addition of midazolam (M) or sufentanil (S) to bupivacaine (B) through intrathecal injection for spinal anesthesia, after the cesarean section.
Patients and methods: In this double blind randomized clinical trial participants were randomly allocated to three equal groups: Group B (2.5 cc of bupivacaine 0.5% + 1 cc normal saline 0.9%), Group BM (2.5 cc of bupivacaine + 0.02 mg/kg midazolam) and Group BS (2.5 cc of bupivacaine 0.5% + 0.7 cc normal saline 0.9% + 1.5 µg of sufentanil, 0.3 cc). We used analysis of variance (ANOVA), post hoc test with Bonferroni adjustment, and chi-square test for statistical analysis; the analyses were performed using the SPSS-16 software. Given a significant level of 0.05, overall and pair-wise comparisons were made.
Results: Seventy-five females participated in the study with no significant age difference (mean ± standard deviation (SD): 28.60 ± 6.06, 28.12 ± 5.29 and 28.76 ± 3.97 year; P = 0.9). Except for "time to motor block recovery" (P = 0.057), the overall differences among the three groups was significant in terms of "time to sensory/motor block" (P < 0.001), "time to sensory block recovery" (P < 0.001), and "time to request opium" (P < 0.001). In all pair-wise comparisons there was no significant difference between the BM and BS group, except for "time to request opium", which was longer in the BS group (P < 0.001). The occurrence of nausea (P = 0.02), postoperative shivering (P = 0.01) and hypotension (P < 0.001) were significantly different between the groups, unlike vomiting, where the difference was not significant (P = 0.2). All neonates had an Apgar score of nine.
Conclusions: The findings showed that adding sufentanil or midazolam to bupivacaine shortens the onset of spinal anesthesia and increases the time duration of anesthesia; however it does not change the motor block recovery time. Adding sufentanil delays the first request for narcotic analgesics while adding midazolam leads to a decrease in nausea and hypotension. Adding sufentanil or midazolam does not have any deleterious effect on infants' Apgar scores. However, increases shivering in patients.
Keywords: Analgesia; Bupivacaine; Cesarean Section; Midazolam; Sufentanil.