Intra-articular morphine or neostigmine does not assure better pain relief

Background and Objectives: Choice of optimal postoperative analgesia technique remains challenging. Our double - blind randomized prospective clinical study compares efficacy of end-of- surgery intra-articular application of morphine or neostigmine after anterior crutiate ligament repair. Methods: 60 adult ASA I - II patients were randomized into 3 groups: intra-articular morphine 6 mg, neostigmine 0.5 mg, placebo. All received femoral nerve block and spinal anesthesia. Numeric rating scale used for pain assessment at rest and motion during 48 postoperative hours, and 0-10 scale for evaluation of overall patient satisfaction. Adjunct analgesics were recorded. Results: The only significant difference between protocol groups was better pain relief at motion at the end of trial in neostigmine 0.5 mg group than in placebo (p=0.018). Consumption of adjuncts wasn’t different on day of surgery, postoperative Day 1 and Day 2 respectively - diclofenac (p=0.85, p=0.41, p=0.9) and tramadol (p=0.62, p=0.72, p=1). Patient satisfaction was similar (p=0.59) among groups. Conclusions: Intra-articular neostigmine provided similar pain control at motion as morphine during the trial, but it was better than placebo on the 2nd postoperative day. Similar pain control at rest, adjunct consumption and patient satisfaction recorded throughout the whole observation period in all groups