Objective To investigate the effects of dexmedetomidine combined with ropivacaine and fentanyl combined with ropivacaine for transversus abdominis plane block(TAPB) on postoperative pain and hemodynamics in women with cesarean section.

Methods A total of 120 puerperas who received cesarean section operations were selected as research objects. All women were divided into group A and group B according to the admission parity order, with 60 cases in each group. Group A was given fentanyl combined with ropivacaine for anesthesia, while group B was given dexmedetomidine combined with ropivacaine for anesthesia. The puerperas of two groups given bilateral TAPB under the guidance of ultrasound. Visual Analogue Scale (VAS) and Quality of Recovery Scale (QoR-40) 24 h after operation were used to evaluate postoperative pain and recovery after childbirth, and maternal heart rate (HR), blood oxygen saturation (SpO₂), level of prolactin secretion, mean arterial pressure (MAP), the number of effective compression, and incidence of adverse reactions were recorded.

Results The VAS scores of 6, 12 and 24 h after operation were higher than those of 2 h, VAS score 12 h after surgery was higher than 6 h after surgery, and VAS score 24 h after surgery was lower than that of 6 and 12 h after surgery, and the differences were statistically significant (P < 0.05). VAS scores of the group B at 6, 12 and 24 h after operation were lower than those of group A, the differences were statistically significant (P < 0.05). Compared with before operation, MAP and SpO₂ decreased and HR increased in both groups at 8 h after operation, but HR of the group B at 8 h after operation was lower than the group A, and SpO₂ level was higher than group A, the differences were statistically significant (P < 0.05). The secretion levels of prolactin in two groups at 12, 24 and 48 h after operation were higher than those at conclusion of operation, the prolactin level at 48 h after operation was higher than that at 12 and 24 h after operation, and prolactin level at 24 h after operation was higher than that at 12 h after operation, the differences were statistically significant (P < 0.05). The prolactin levels of the group B at 12, 24 and 48 h after operation were higher than those of the group A (P < 0.05). The QoR-40 score of the group B was higher than that of the group A, and the number of effective compression was less than that of group A(P < 0.05). The incidence of adverse reactions in the group B was 5.00% (3/60), which was lower than 16.67% (10/60) in the group A (P < 0.05).

Conclusion Both dexmedetomidine and fentanyl have good analgesic effect. However, dexmedetomidine combined with ropivacaine has better effect on postoperative pain than that of fentanyl combined with ropivacaine, and has less influence on cardiovascular system and hemodynamics. Besides, it is beneficial to early lactation of puerperas, can reduce the body's demand for anesthetic drugs, decrease the incidence of adverse reactions induced by drugs, and accelerate the early postpartum recovery of puerperas.