Presurgical fentanyl vs caudal block and the incidence of adverse respiratory events in children after orchidopexy.

Background: There is controversy about the etiology of early postoperative hypoxemia. Age, weight, intubation, surgical procedure, use of muscle relaxants, and/or administration of opioids may affect the incidence of early postoperative hypoxemia. In this prospective, randomized, and single-blinded study, we evaluated whether the administration of caudal analgesia vs i.v. fentanyl affected the number of children who develop postextubation adverse upper airway respiratory events, (upper airway obstruction, laryngospasm) and/or early postoperative hypoxemia.

Methods/materials: Institutional approval and written parental informed consents were obtained. Thirty-eight healthy outpatient boys, aged 1-6 years, scheduled for elective orchidopexy were randomized to receive pain relief either with a presurgical caudal block or by i.v. fentanyl. The primary outcome of the study was the number of children who developed postextubation adverse upper airway respiratory events and/or early postoperative hypoxemia.

Results: The number of boys who developed postextubation adverse upper airway respiratory events and/or early postoperative hypoxemia in the caudal group was less compared with those in the fentanyl group (P = 0.04).

Conclusions: Compared to fentanyl, placement of a presurgical caudal block in boys scheduled for orchidopexy was associated with a lower incidence of postextubation adverse upper airway respiratory events and/or early postoperative hypoxemia.