Anders Peder Højer Karlsen

Background The leading principle in peri‐operative pain management is multimodal analgesia, which reduces opioid requirements and associated adverse effects. Pragmatic pain trials should optimally test interventions in addition to multimodal non‐opioid analgesics and interventions to ensure clinical relevance and baseline levels of opioid consumption that reflect clinical settings. We aimed to investigate opioid consumption and use of non‐opioid analgesics administered adjunct to interventions in post‐operative pain trials after total hip and knee arthroplasty. Methods A systematic literature search was conducted 7 January 2020 in The Cochrane Library's CENTRAL, PubMed, and EMBASE. Trials investigating analgesic interventions for post‐operative pain in adults undergoing total hip or knee arthroplasty were included. The primary outcome was the aggregated median 0–24 h post‐operative opioid consumption. Further, we assessed the use of paracetamol, non‐steroidal anti‐inflammatory drugs, gabapentinoids, high‐dose glucocorticoids, local infiltration analgesia and nerve blocks administered as co‐interventions equally to all participants. We assessed trends over time for all outcomes. Results Of 14,200 records, 570 trials were included. Median 0–24 h opioid consumption was 21 and 22 mg iv morphine equivalents in hip and knee arthroplasty trials, respectively. Meta‐regression showed no overall linear correlation between opioid consumption and publication year. The use of multimodal non‐opioid analgesia increased over time, though only 48% of trials published from 2010 to 2020 administered two or more non‐opioid analgesics. Applying more non‐opioid analgesics was associated with lower opioid consumption in intervention groups. Conclusion Post‐operative 0–24 h morphine consumption was median 21–22 mg. The demonstrated differences in non‐opioid multimodal analgesic regimens between research and clinical settings, can potentially diminish the demonstrated opioid‐sparing effects of trial interventions when such are implemented in a clinical context.