System-related events and analgesic gaps during postoperative pain management with the fentanyl iontophoretic transdermal system and morphine intravenous patient-controlled analgesia.

BACKGROUND

Analgesic gaps (interruptions in analgesic delivery) contribute to ineffective postoperative pain management. In this analysis, we evaluated the incidence of analgesic gaps resulting from system-related events (SREs) for patients using the fentanyl iontophoretic transdermal system (ITS), a noninvasive patient-controlled analgesia (PCA) system, or morphine IV PCA for postoperative pain management.

METHODS

Data were pooled from two open-label, randomized, active-controlled trials that evaluated the efficacy and safety of fentanyl ITS and morphine IV PCA after total hip replacement, abdominal, or pelvic surgery. The incidence and duration of analgesic gaps resulting from SREs were assessed, along with SRE resolution times.

RESULTS

A total of 1305 patients received fentanyl ITS (n = 647) or morphine IV PCA (n = 658). Fentanyl ITS was associated with a significantly lower incidence of analgesic gaps per 100 patients compared with morphine IV PCA (5.87 vs 12.01, respectively; P < 0.001). Compared with patients receiving morphine IV PCA, patients receiving fentanyl ITS had both a numerically lower median total analgesic gap time (15.0 min vs 20.0 min) and a numerically lower median total SRE resolution time (11.0 min vs 20.0 min). Most fentanyl ITS SREs were resolved by applying a new system, whereas many different SRE resolution methods were used for morphine IV PCA.

CONCLUSIONS

Fentanyl ITS was associated with a significantly lower incidence of analgesic gaps relative to morphine IV PCA. Fentanyl ITS may provide patients with fewer interruptions and more continuous analgesic delivery.