Methods: Sixty-three healthy patients undergoing knee arthroscopy under local anesthesia (LA) were randomized to receive 1 of the following substances intra-articularly postoperatively: group B: 30 mL of bupivacaine (150 mg); group R: 30 mL of ropivacaine (150 mg); and group RMK: ropivacaine 150 mg, morphine 4 mg, and ketorolac 30 mg in normal saline (total volume 30 mL). Oral paracetamol 1g and tramadol 50 mg were used as rescue drugs. Postoperatively, pain was assessed at rest and movement, and side effects were recorded. The patients were asked to self-assess pain for 7 days and record analgesic consumption as well as activities of daily living (ADLs). Plasma concentration of LA was measured in another 8 patients.

Results: All groups had excellent analgesia at 0 and 4 hours postoperatively. Group RMK had significantly lower visual analog pain score at rest at 8 hours and during movement at 8 and 24 hours compared with the other groups (P < .05). Group RMK required less paracetamol and tramadol on day 1 (P < .05), had less sleep disturbances because of pain, more patients were ready to work on days 1 and 2 (P < .05), and were more satisfied on days 1 and 4 to 7. Postoperatively, plasma concentrations of ropivacaine and lidocaine were far below known systemic toxic concentrations in all patients.

Conclusion: Addition of morphine and ketolorac to ropivacaine intra-articularly enhances analgesic efficacy of LA, reduces postdischarge analgesic consumption, and improves ADLs without increasing side effects after ambulatory arthroscopic knee surgery.