Effectiveness of remifentanil in reducing blood loss in orthognathic surgery: a systematic review

Introduction Remifentanil is widely used in orthognathic surgery for intra-operative pain management, inducing hypotension, and controlling intra-operative blood loss (IBL).Aim To evaluate the effectiveness of remifentanil in reducing IBL during orthognathic surgery compared with other hypotensive agents.Methods A systematic review was conducted across seven databases and grey literature up to May 2024, restricted to randomised controlled trials (RCTs). Risk of bias was assessed with RoB 2.0, and certainty of evidence with GRADE.Results From 3,883 articles, eight studies were included (388 participants, aged 22-29 years), and four contributed to meta-analysis. Qualitative synthesis showed greater IBL reduction with remifentanil within balanced anaesthesia protocols, especially when combined with sevoflurane. The meta-analysis found no significant difference between remifentanil and nitroglycerin (RR = 13.37; 95% CI: -84.18 to -110.72; very low certainty). When combined with sevoflurane, compared with desflurane and isoflurane, no significant effect was observed, though a trend favoured sevoflurane (RR = -0.26; 95% CI: -0.59 to -0.07; low certainty).Discussion Although remifentanil may reduce IBL, conflicting results and low certainty limit conclusions. Cardiovascular risks and delayed bleeding require attention. Evidence gaps include pseudoaneurysm incidence, osteotomy-specific outcomes, and transfusion needs.Conclusion Remifentanil may contribute to IBL reduction, particularly with sevoflurane, but evidence remains low certainty. Further high-quality RCTs are needed.