Comparison of preincisional and postincisional parasternal intercostal block on postoperative pain in cardiac surgery

Background The optimum cardiac surgical pain management has known to maintain hemodynamic stability and, reduces respiratory and cardiovascular complications. Postoperative parasternal intercostal block has shown to reduce postoperative analgesic consumption after cardiac surgery. Therefore, this study sought to investigate the effectiveness of the preoperative ultrasound guided parasternal block in reducing postoperative pain after cardiac surgery. Methods This was a randomized, prospective, interventional, single blind study comprised of 90 adult patients scheduled for cardiac surgery involving sternotomy. Preoperatively and postoperatively, 0.25% bupivacaine administered in 4 mL aliquots into the anterior (2nd‐6th) intercostal spaces on each side about 2 cm lateral to the sternal edge with a total volume of 40 mL under ultrasound guidance and direct vision, respectively. Postoperative pain was rated according to visual analogue scale. Secondary outcomes included intraoperative and postoperative fentanyl consumptions, dosages of rescue medications, and time to extubation. Main results There was no significant differences in visual analogue score visual analogue score at all time points till 24 hours postoperatively. Intraoperative fentanyl requirements (microgram/kg) before cardiopulmonary bypass was significantly lower in pre‐incisional group than the post‐incisional group (0.16 ± 0.43 vs 0.68 ± 0.72; P = .0001). Furthermore, there were no significant difference in total fentanyl requirement (7.20 ± 2.66 vs 8.37 ± 3.13; P = .06) and tramadol requirement (0.02 ± 0.15 vs 0.07 ± 0.26; P = .28) within first 24 hours. However, time to extubation was significantly higher in the preoperative group (P = .02). Conclusions Preoperative and postoperative parasternal intercostal block provide comparable pain relief during the postoperative period.