Comparative Study of Ropivacaine and Ropivacaine With Dexmedetomidine in Transversus Abdominis Plane (TAP) Block for Post-operative Analgesia in Patients Undergoing Cesarean Sections.

Abstract

Background Adequate post-operative analgesia in the obstetric patient is necessary to facilitate breastfeeding and the care of the newborn. Considering the limitations of intravenous analgesic options such as non-steroidal anti-inflammatory drugs (NSAIDs) and opioids, other alternatives have been tried for offering better analgesia with fewer potential side effects. Transversus abdominis plane (TAP) block is one such option that has been tried with various local anesthetic drugs, either alone or in combination with other adjuvants. The addition of dexmedetomidine to bupivacaine in TAP block has been shown to prolong the duration of post-operative analgesia when compared to local anesthetic alone. This study was conducted to determine the efficacy of dexmedetomidine, as an adjuvant to ropivacaine, when administered in TAP block in patients undergoing cesarean section. Methodology The study was a prospective, randomized, parallel assignment, triple-blinded controlled trial. Hundred patients posted for elective lower segment cesarean section, fulfilling the inclusion criteria, were randomly divided into two equal groups, group R and group RD, comprising 50 patients each. Patients in group R were administered bilateral TAP block by landmark technique using ropivacaine alone, whereas patients in group RD were administered TAP block with dexmedetomidine 1 micrograms/kg, in addition to a similar dose of ropivacaine. Mean arterial pressure (MAP), heart rate (HR), visual analog scale (VAS)-R (pain score on VAS scale at rest), VAS-C (pain score on VAS scale on coughing), nausea and vomiting, and Ramsay sedation score were recorded on admission to post-operative care unit (PACU), and at first, fourth, eighth, 12th, 18th,and 24th hours post-operatively. Rescue analgesia was provided with intravenous morphine. Short Assessment of Patient Satisfaction Score (SAPS) was noted on a five-point scale after 24 hours based on patient satisfaction regarding the quality of post-operative analgesia. Results While there was no significant difference between groups R and RD with respect to VAS-C and VAS-R immediately after shifting and at the first, fourth, and eighth hours, a significant difference was observed at the 12th and 18th hours post-operatively. After 24 hours, no significant difference was observed between groups R and RD with respect to VAS-C and VAS-R. While 50% of patients needed rescue analgesia in group R, only 28% of patients needed rescue analgesia in group RD. There was significantly better patient satisfaction measured by the Short Assessment of Patient Satisfaction Score (SAPS) with respect to the quality of analgesia in patients in group RD as compared to those in group R. Conclusions The addition of dexmedetomidine to ropivacaine increased the duration of post-operative analgesia up to 18 hours post-operatively in cases of elective lower segment cesarean section. Also, the quality of post-operative analgesia is better in such patients, as shown by a significant difference in patient satisfaction scores between the two groups.