Intraoperative respiratory and hemodynamic strategies for reducing nausea, vomiting, and pain after surgery: Systematic review and meta‐analysis

BACKGROUND: Despite improved medical treatment strategies, postoperative pain, nausea, and vomiting remain major challenges. This systematic review investigated the relationship between perioperative respiratory and hemodynamic interventions and postoperative pain, nausea, and vomiting. METHODS: PubMed and Embase were searched on March 8, 2021 for randomized clinical trials investigating the effect of perioperative respiratory or hemodynamic interventions in adults undergoing non‐cardiac surgery. Investigators reviewed trials for relevance, extracted data, and assessed risk of bias. Meta‐analyses were performed when feasible. GRADE was used to assess the certainty of the evidence. RESULTS: This review included 65 original trials; of these 48% had pain, nausea, and/or vomiting as the primary focus. No reduction of postoperative pain was found in meta‐analyses when comparing recruitment maneuvers with no recruitment, high (80%) to low (30%) fraction of oxygen, low (5–7 ml/kg) to high (9–12 ml/kg) tidal volume, or goal‐directed hemodynamic therapy to standard care. In the meta‐analysis comparing recruitment maneuvers with no recruitment maneuvers, patients undergoing laparoscopic gynecological surgery had less shoulder pain 24 h postoperatively (mean difference in the numeric rating scale from 0 to 10: −1.1, 95% CI: −1.7, −0.5). In meta‐analyses, comparing high to low fraction of inspired oxygen and goal‐directed hemodynamic therapy to standard care in patients undergoing abdominal surgery, the risk of postoperative nausea and vomiting was reduced (odds ratio: 0.45, 95% CI: 0.24, 0.87 and 0.48, 95% CI: 0.27, 0.85). The certainty in the evidence was mostly very low to low. The results should be considered exploratory given the lack of prespecified hypotheses and corresponding risk of Type 1 errors. CONCLUSION: There is limited evidence regarding the impact of intraoperative respiratory and hemodynamic interventions on postoperative pain or nausea and vomiting. More definitive trials are needed to guide clinical care within this area.