Background and objectives: Methods to promote knee pain analgesia without impairing motor function have been widely researched. This study aimed at comparing intra-articular morphine, bupivacaine, and fentanyl analgesic effects (as compared to saline solution), after knee video-arthroscopy.
Methods: Participated in this study 60 patients who were randomly distributed in four groups: GI (n = 15) 10 ml saline solution; GII (n = 15) 2 mg morphine diluted in 10 ml saline solution; GIII (n = 15) 10 ml of 0.25% bupivacaine; GIV (n = 15) 100 microg fentanyl diluted in 10 ml saline solution, injected at surgery completion. All patients received spinal anesthesia with 15 mg hyperbaric bupivacaine. Pain intensity was evaluated by a visual analog scale (VAS) (at surgery completion, and 6, 12, 18 and 24 hours later). The need for analgesic complementation (1 g intravenous dipirone) was also evaluated. Side effects were recorded.
Results: There were no statistical differences in pain intensity among groups in almost all moments studied. There was a statistic difference up to 6 hours, when the fentanyl group had significantly lower pain. The morphine group needed more dipirone complementation. Side effects were minor, without statistical significance.
Conclusions: There were no statistical differences among solutions analgesic effects in almost all moments studied.