The influence of lockout intervals and drug selection on patient-controlled analgesia following gynecological surgery.

Abstract

This study systematically compared 2 opioids, morphine (MOR) and fentanyl (FEN), and 2 lockout intervals, long (L) and short (S) in patients utilizing patient-controlled analgesia (PCA). Seventy-eight women undergoing gynecological surgery were randomly assigned to 1 of 4 groups: MOR-S (7 min), MOR-L (11 min), FEN-S (5 min), FEN-L (8 min). PCA measures obtained during the first 24 h after surgery included: number of demands/h, number of completed deliveries/h, dose/h, and demand/delivery ratio. Visual analog scales of pain and anxiety were also obtained. Results indicated that pain relief was equivalent with minimal side effects for both opioids. The selection of opioid, however, influenced the pattern of PCA use, with an improved demand/delivery ratio initially for FEN. The lockout intervals chosen for this study did not influence pain or anxiety levels.