Effects of Intrathecal vs. oral Multimodal analgesia on pain scores following total knee and hip arthroscopy procedures

Abstract

Background Postoperative pain management practices vary widely among anesthetists in hospitals despite evidence-based pain management guidelines. This study explores a specific practice in managing acute post-operative pain by comparing the use of intrathecal bupivacaine (ITB) and morphine (ITBM) combined with oral multi-modal analgesia (MMA) versus ITB and oral MMA in patients who have undergone total knee arthroscopy (TKA) and total hip arthroscopy (THA) and the effect on pain scores. This study seeks to determine whether the practice of using ITBM is beneficial to patients during the post-operative phase. A total of 153 patients undergoing TKA and THA orthopedic surgery were randomly assigned to one of the two pain management techniques: (1) 3.5ml of 0.5% isobaric bupivacaine injected intrathecally and MMA (500mg of acetaminophen, 200mg gabapentin, 200mg of celecoxib, 10mg of controlled release oxycodone, and 5-15mg of immediate release oxycodone) was initiated on postop day 0; and (2) 3.5ml of 0.5% isobaric bupivacaine and 0.1mg of morphine was injected intrathecally and MMA (500mg of acetaminophen, 200mg gabapentin, 200mg of celecoxib, 10mg of controlled release oxycodone, 5-15mg of immediate release oxycodone). Verbal pain scores were monitored for the first 24 hours post-operatively using the Visual Analog Scale (VAS). Side effects of nausea and vomiting were also monitored for each patient for the first 24 hours post operatively. Results The VAS were similar in the ITBM group and the ITB group during the first 24 hours post-operative. The mean VAS 24 hours post-operative for TKA patients who received ITBM was 4.98, and 5.45 for patients who received ITB. Post-operative nausea and vomiting (PONV) in the TKA group varied according to the treatment group, 12.7% of patients in the ITBM group reported nausea or vomiting, compared to 13.2% in the group of patients who received ITB. The significance is set at P value < 0.05, based off this set value, the significance is shown to be P=0.629 (N.S.). There was no significance in VAS when treated with ITB or ITBM. The mean pain score 24-hour post-operative for THA patients who received ITBM was 3.63 and 4.04 for patients who received ITB. In the THA group, 9.1% of patients in the ITBM group reported PONV, whereas no one experienced PONV in the ITB group. The significance is set at P value < 0.05, based off this set value, the significance is shown to be 0.708 (N.S.). There is no significance in pain scores when treated with ITB or ITBM in patients who have undergone a total hip arthroplasty. In Conclusion, the use of ITBM fails to show superior analgesic effect on patients undergoing TKA and THA compared to ITB combined with MMA. Without superior pain control benefits and mild increase risk of causing nausea and vomiting post operatively in the TKA group, intrathecal morphine shows to provide no additional superior benefits to patients in managing their pain or significantly decreasing severity of onset of pain post operatively.