Opioid and nerve block administration in knee arthroplasty: An observational retrospective evaluation

Aims Increasing opioid-related adverse events and deaths have amplified interest in non-opioid analgesic options. Peripheral nerve blocks (PNBs) are useful in pain management, especially in minimally invasive day surgeries. This evaluation sought to examine patterns of opioid use among adult patients undergoing total knee arthroplasty, stratified by use of PNBs. Design A retrospective, observational design. Settings A large tertiary medical center and community hospital in the Inland Northwest. Participants/Subjects A dataset of 8,493 adult patients undergoing elective total knee arthroplasty, 3,432 of which received a PNB while 5,061 did not. Methods A deidentified dataset was obtained to evaluate: (a) opioid use frequency, (b) average morphine milligram equivalents (MMEs) administered, (c) independent factors associated with opioid administration, and (d) time to first opioid administered in adults undergoing total knee arthroplasty while in the recovery room, stratified by use of PNBs. Results When controlling for general anesthesia, opioid use frequency was reduced when PNBs were administered (p \u3c .05). The amount of MMEs consumed was 15 mg less in the group receiving a PNB (p \u3c .001). In a linear regression model, PNBs reduced the MMEs consumed by 5 mg (p = .014). Time-to-first opioid was increased in patients receiving general anesthesia and PNBs with a hazards ratio of 0.70 (p \u3c .001). Conclusions Peripheral nerve blocks are an opioid-sparing technique in adult patients undergoing total knee arthroplasty. Clinical Implications The results confirm best practices regarding opioid-sparing PNBs. Postoperative opioids are appropriate, but regimens incorporating PNB administration for total knee arthroplasty help reduce opioid use