The effect of dexmedetomidine on extubation at operating room and postoperative pain management of pediatric patients undergoing congenital heart surgery

In paediatric patients undergoing congenital heart surgery, early extubation and effective postoperative pain management are the main steps of the fast-track cardiac surgery which aims to reduce the cost and complications of heart surgery. In this study, the effects of intravenous dexmedetomidine administration (beginning at preoperatively or at the closure of sternum) on postoperative pain management and morphine consumption were investigated in pediatric congenital heart surgery patients extubated at the operating table. After approval of Faculty Ethical Committee and parents consent, 53 children, 1-15 years old, undergoing corrective congenital heart surgery were included the study. After iv ketamin (2 mg/kg) premedication, anaesthesia was maintained with sevoflurane in all children. Immediately after the surgical incision, all children received morphine, 0.1 mg/kg, intravenously for perioperative analgesia. Ketamin, 2 mg/kg,iv, was used in all children during the rewarming of bypass. Children were divided into three groups randomly. In the first group, dexmedetomidine infusion was started just before operation in a dose of 1 mcg/kg and continued with a dose of 0.3 mcg/kg/h during the operation. In the second group, same bolus dose of dexmedetomidine was infused just before the sternal closure. In Group III, only morphine was injected in a dose of 0.05 mg/kg intravenously during the sternal closure for postoperative analgesia. The children meeting the extubation criteria (effective spontaneous breathing, response to verbal orders, stable haemodynamic parameters and oropharyngeal temperature above 36.5 Co) were extubated at the operating table. In the postoperative period, children in group I and II received dexmedetomidine infusion in a dose of 0.3 mcg/kg/h for 24 hour except in group III which saline infusion was used in the same volume. Intravenous morphine (0.025 mg/kg) supplements were used in the children having pain (CHEOPS) score>7. Pain scores, morphine consumption, blood cortisol and glucose levels and hemodynamic parameters were recorded up to 24 hour. Time to awakening and time to extubation were found significantly longer in the both dexmedetomidine groups than morphine group (p<0.05). CHEOPS scores, mean blood cortisol levels and daily morphine consumption were lower in Groups I and II than Group III (p<0.05), but there was no significant difference in these parameters between group I and II. No complication related to the study drugs was observed. Conclusion, in pediatric congenital heart surgery patients extubated at the operating table, intravenous dexmedetomidine administration beginning both at preoperatively and at the closure of sternum resulted in better postoperative pain management and lower morphine consumption without prolonging the duration of extubation compared with morphine group. Key words: Congenital heart surgery, postoperative pain management, early extubation, dexmedetomidine