COMPARISON OF CONTINUOUS-INFUSION OF FENTANYL TO BOLUS DOSING IN NEONATES AFTER SURGERY

Objective: Concern about respiratory depression may lead to underuse o f postoperative narcotic analgesia in neonates. The authors compared c ontinuous infusion of fentanyl with bolus dosing in infants after surg ery to determine whether continuous infusion is associated with less r espiratory depression. Study Design: In the first phase of the study, 16 patients were randomly assigned to receive fentanyl by continuous i nfusion (C) or bolus dosing every 2 hours (B) in a double-blinded tria l. Respiratory events were recorded. An observational pain score and s aliva for cortisol concentration were obtained 2, 8, and 24 hours afte r beginning treatment to compare efficacy of pain control, In the seco nd phase, 20 additional patients received fentanyl by continuous infus ion in an unblinded fashion, with the same data collection, to more ac curately determine the incidence of respiratory events. Results: In ph ase 1, apnea occurred in eight of nine B patients (89%) compared with one of seven C patients (14%; P < .009), prompting termination of the randomized trial. The incidence of apnea or significant respiratory de pression in the next 20 patients (phase 2) who received fentanyl by co ntinuous infusion was 25% (5 of 20; P < .01 v B). Episodes of apnea in B patients required significantly more intervention than episodes in C patients (P < .01). However, in phase 2, more patients remained intu bated and ventilated than in phase 1. pain scores and salivary cortiso l concentrations decreased over the 24-hour study period and were simi lar in B and C patients during both phases of the study. Conclusion: C ontinuous infusion of fentanyl at the doses studied is associated with pain control similar to that with bolus dosing at regular intervals. Although episodes of respiratory depression were less severe and less frequent for C patients, there may be an increased need for ventilator support with continuous infusion of fentanyl to achieve acceptable pa in control. Providing adequate pain control to neonates in the immedia te postoperative period remains a challenge. Copyright (C) 1996 by W.B . Saunders Company.