PAIN RELIEF AFTER KNEE ARTHROSCOPY - INTRAARTICULAR MORPHINE, INTRAARTICULAR BUPIVACAINE, OR SUBCUTANEOUS MORPHINE

Background and Objectives. This investigation was undertaken to compar e analgesic effects, side effects, and requirements for supplemental a nalgesic therapy after knee arthroscopy in patients given intra-articu lar (IA) or subcutaneous (SC) morphine, intra-articular bupivacaine, o r placebo. Methods. In a randomized, double-blind controlled trial, 11 2 patients, 14-65 years old each received two solutions, one SC and th e other IA. Group IAM (n = 30) received 10 mg IA morphine in 20 mL, no rmal saline plus 1 mt of SC normal saline Group IAB (n = 27) received 20 mt IA bupivacaine 0.5% with IA epinephrine plus 1 mt SC normal sali ne Group SCM (n = 26) received 20 mt IA normal saline plus 10 mg SC mo rphine in 1 mt. Group P (n = 29) received 20 mt IA normal saline plus 1 mt SC normal saline. Pain was evaluated on arrival in the postanesth esia care unit (PACU), and 30, 45, 60, 90, and 120 minutes afterwards. If pain exceeded 4/10 on a visual analog pain scale in the PACU, 30 m g intravenous ketorolac was given, and if pain persisted, 0.4 mg hydro morphone was added every 7 minutes. After PACU discharge, patients who se pain exceeded 4/10 received oral ketorolac 10 mg every 6 hours; ora l acetaminophen plus codeine was added every 4 hours if pain still exc eeded 4/10. Analgesic requirements, along with visual analog pain scor e, sedation, and nausea were recorded every 6 hours for 72 hours. Resu lts. All three active (nonplacebo) pain treatments provided good pain control in the PACU. Side effects were similar in all groups. The plac ebo group had higher pain scores at 120 minutes (R = .02), higher supp lemental analgesic requirements at 60 minutes (P = .04) and 90 minutes (P = .02) and the highest amount of total opioid rescue dose (P = .04 ). Patients in groups LAB and P had higher visual analog pain scores a t 6 hours (P = .04) and 30 hours (P = .049) than those in Groups IAM a nd SCM. Conclusion. A single 10-mg dose of morphine given either IA or SC provides better and longer-lasting postoperative pain relief after knee arthroscopy than 20 mt IA bupivacaine 0.5% with epinephrine.