Effects of dexmedetomidine on emergence delirium in pediatric cardiac surgery

The present study aimed to investigate the effects of dexmedetomidine on emergence delirium (ED) in pediatric patients undergoing cardiac surgery.

Fifty children of both sexes aged 1-6 years weighing 10-25 kilograms, with American Society of Anesthesiologists (ASA) physical status grade II, undergoing sevoflurane-based general anesthesia for elective cardiac surgery, were randomly assigned to two groups. The dexmedetomidine group (group D, N.=25) received 0.5 µg/kg of dexmedetomidine over 10 minutes, followed by an infusion at 0.5 µg/kg/h until the end of the surgery, whereas the saline group (group S, N.=25) received volume-matched normal saline immediately after the induction of anesthesia. Blood samples were taken preoperatively (T0), at different time points during surgery (T1-T5), and during the postoperative period (T6-T7) to determine serum melatonin, cortisol, norepinephrine, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and blood glucose levels. In the cardiac intensive care unit (CICU), the incidence of ED was assessed with a 5-point scale, and the severity of ED was assessed with the Pediatric Anesthesia Emergence Delirium scale (PAED) every two hours for the first 24 hours after surgery. ED was considered when the 5-point scale score was ≥4 for more than 5 minutes, or the PAED score was ≥10.

Based on comparable demographic profiles, the scores of the 5-point scale and PAED Scale were significantly lower in group D compared with group S (P=0.028 and P=0.009, respectively). In addition, the fluctuation in the level of melatonin was significantly less in group D. Serum cortisol, norepinephrine, IL-6, TNF-α and glucose levels were increased in the two groups, but these increases were significantly less in group D than in group S. The consumption of sevoflurane during anesthesia was significantly less in group D (P=0.0002). The postoperative consumption of fentanyl was less in group D (P=0.04), whereas the pain scores were not significantly different (P=0.502). Extubation time was significantly delayed in group D compared with group S (P=0.032), whereas CICU and hospital stay were comparable between the two groups.

Continuous intraoperative infusions of dexmedetomidine in pediatric patients undergoing cardiac surgery reduce sevoflurane requirements and decrease the incidence of ED, which is associated with decreasing plasma melatonin levels and surgical stress.