Analgesia Quality and Duration of Fentanyl and Sufentanil Added to Bupivacaine in Spinal Anesthesia in Inguinal Hernia Surgery: A Double-Blind Parallel Randomized Controlled Trial.

BACKGROUND AND AIMS

To compare the quality and duration of analgesia provided by Fentanyl and Sufentanil when added to 12-15 mg Bupivacaine 0.5% in spinal anesthesia for inguinal hernia surgery.

METHODS

In the present double-blind parallel Randomized Controlled Trial (RCT), 180 patients who were candidates for elective inguinal hernia surgery were divided into three groups using balanced-block randomization. The first group received 2.5 cc Bupivacaine with 0.5 cc (25 mg) Fentanyl, the second group received 0.5 cc (2.5 micrograms) of Sufentanil with 2.5 cc Bupivacaine, and the third group received 2.5 cc Bupivacaine with 0.5 cc normal saline. The pain score was evaluated by VAS (visual analog scale) at recovery and arrival in PACU, 2, 4, 6, and 12 h after the surgery.

RESULTS

A total of 60 subjects were allocated to each group. The mean (standard deviation) of pain score 2 h after surgery in Bupivacaine, Bupivacaine-Fentanyl, and Bupivacaine-Sufentanil were 1.73 (0.49), 1.10 (1.10), and 1.22 (1.25), respectively. These values 12 h after surgery were 2.76 (0.36), 2.97 (0.61), and 2.92 (0.56), respectively. The within-group comparison showed a significant increase in the pain score over time ( < 0.001). Also, the between-group comparison revealed significant differences between the three groups regarding pain scores ( = 0.030), so that the mean and standard deviation of pain score in Bupivacaine (1.67 ± 0.05) was higher than Bupivacaine-Fentanyl (1.51 ± 0.09) ( < 0.001) and Bupivacaine-Sufentanil (1.52 ± 0.08) ( < 0.001), but Bupivacaine-Fentanyl was not different from Bupivacaine-Sufentanil ( = 0.437). Results showed a significant interaction between time and intervention for pain score ( < 0.001).

CONCLUSIONS

The pain-reducing effects of Sufentanil and Fentanyl, when combined with Bupivacaine, were significantly greater than those of Bupivacaine alone. However, this effect lasts only for up to 4 h after surgery, after which their efficacy diminishes.