Effect of dexamethasone as an adjuvant to ropivacaine on duration and quality of analgesia in ultrasound-guided transversus abdominis plane block in patients undergoing lower segment cesarean section - A prospective, randomised, single-blinded study

BACKGROUND AND AIMS: Ultrasound guided transversus abdominis plane block is an efficacious abdominal field block. The aim was to determine the effect of dexamethasone to 0.375% ropivacaine on the analgesic duration of TAP block in patients undergoing lower segment cesarean section (LSCS). METHODS: A single-blinded randomised control study was conducted on 90 patients, who were divided in two groups of 45 each. Group R received 0.375% ropivacaine (25 ml) with normal saline (1 ml) each side and group D received 0.375% ropivacaine (25 ml) with dexamethasone 4 mg (1 ml) each side in transversus abdominis plane block after lower segment cesarean section. Primary objective was to compare time to first rescue analgesia and secondary objectives to compare the total amount of analgesia required in first 24 h postoperatively, visual analog scale scores for somatic and visceral pain and incidence of nausea and vomiting, between the two groups. Student's t test, Chi-square, or Fisher's exact test were performed using SPSS 17.0. RESULTS: Time to first rescue analgesia was significantly less in group R (11.62 ± 3.80 h) compared to group D (19.04 ± 4.13 h) (P < 0.001). Total tramadol consumed in 24 h was significantly higher in group R (86.67 ± 30.55 mg) than group D (35.56 ± 39.54 mg) (P < 0.001). Visual analog scale scores for both somatic and visceral pain were significantly higher in group R than group D at 8 h, 12 h, and 24 h postoperatively. CONCLUSION: Addition of dexamethasone to ropivacaine in transversus abdominis plane block significantly prolongs the duration of postoperative analgesia.