A meta-analysis evaluates the efficacy of intravenous acetaminophen for pain management in knee or hip arthroplasty

Background: The objective of this study was to assess whether intravenous acetaminophen for patients undergoing knee or hip arthroplasty could reduce the opioid consumption and improve pain management. Method: Eligible studies were searched from electronic databases including PubMed, Web of Science, Embase (Ovid interface) and Cochrane Library (Ovid interface). The quality assessments were performed according to the Cochrane systematic review method. The assessed outcomes were including opioid consumption, pain scores, length of hospital stays and total occurrence of adverse events. Results: Among 832 records identified, six randomized controlled trials (RCTs) and five non-RCTs were eligible for data extraction and meta-analysis. According to the outcomes, the patients receive intravenous acetaminophen had less total opioid consumption after knee or hip artroplasty (SMD = -0.66; 95%CI, -1.13 to -0.20), but they did not obtain statistical improvement of postoperative pain control at postoperative day 0 (POD0, SMD = -0,15; 95%CI, -0.36 to 0.07), POD1(SMD = 0,12; 95%CI, -0.13 to 0.36), POD2 (SMD = -0,29; 95%CI, -0.70 to 0.12) and POD3 (SMD = -0,04; 95%CI, -0.49 to 0.41). Meanwhile, there were similar outcomes about the length of hospital stays in patients whether or not receiving intravenous acetaminophen (SMD = -0,05; 95%CI, -0.26 to 0.15). And, the total adverse effects occurrence also didn't show any significant difference between the acetaminophen group and control group (OR = 0.87; 95%CI, 0.57 to 1.33). Conclusions: Perioperative intravenous acetaminophen use in multimodal analgesia could significantly reduce of total opioid consumption, but it did not contribute to decrease the average pain scores and shorten the length of hospital stays in total hip or knee arthroplasty. (C) 2018 Published by Elsevier B.V. on behalf of The Japanese Orthopaedic Association.