Objective: Perioperative opioid consumption is one important factor that can lead to postoperative complications following surgery in pediatric patients. Our hypothesis is the techniques of anesthesia are predictive factors for intraoperative fentanyl consumption. We have also tried to explore which of the existing factors might be associated with intraoperative and the post-anesthetic care unit (PACU) fentanyl consumption in children who undergo elective, urologic surgery.

Material and methods: After approval from the Ethics Committee of Songklanagarind Hospital, the anesthetic charts were retrospectively reviewed in 147 children, aged 0-9 years, from January, 2005 to December, 2007. The variables considered were age, weight, sex, technique of anesthesia, type of surgery, duration of surgery and type of anesthetic agent. Perioperative fentanyl consumption was analyzed by univariate and multivariate logistic regression analysis.

Results: Intraoperative fentanyl consumption was associated with the anesthetic technique and type of surgery (p=0.013). General anesthesia combined with caudal or ilioinguinal nerve block decreased the probability of fentanyl required > 1 mcg/kg compared to general anesthesia alone with adjusted odd ratios (95% confidence interval) of 0.02 (0.01-0.09) and 0.06 (0.02-0.22) respectively (p < 0.001). PACU fentanyl consumption was significantly more likely to require in female cases (p = 0.04), in cases induced with propofol and sevoflurane (p=0.002) and in cases with sevoflurane anesthesia (p=0.04).

Conclusions: The predictive factors of intraoperative fentanyl consumption were the anesthetic technique and type of surgery. The predictive factors of PACU fentanyl consumption were sex and anesthetic agent.