Effect of opioid-free anaesthesia on post-operative period in cardiac surgery: a case-control study

Abstract

Background No study has demonstrated feasibility and improvement of opioid free anaesthesia in cardiac surgery. The objective of the present study was to evaluate the effect of opioid-free anaesthesia (OFA) on post-operative morphine consumption and the post-operative course. Methods We performed a retrospective matched cohort study (1:1) in cardiac surgery with cardiopulmonary bypass. Patients were divided into two groups: OFA or opioid anaesthesia (OA). The main outcome was the cumulated total morphine consumption during the 48 post-operative hours. The secondary outcomes included rescue analgesics, a major adverse event composite endpoint, and the length of stay (LOS) in the ICU and in hospital. Results 110 were matched (OFA: n=55; OA: n=55). On inclusion, OFA and OA groups did not differ significantly in terms of demographic and surgical data. The total morphine consumption was higher in the OA group than in the OFA group (15 (6-34) mg vs 5 (2-18) mg, p=0.001). Analgesic rescue did not differ between the two groups. The pain score during the first 48 post-operative hours did not differ between the two groups. Incidence of the composite endpoint was lower in the OFA group (25 patients (43%) vs 38 patients (68%), p=0.021) in relation to lower use of non-invasive ventilation (15% vs 49%, p=0.032). The time to extubation and the ICU stays were shorter in the OFA group (3 (1-5) vs 5 (3-6) hours, p=0.001 and 2 (1-3) vs 3 (2-5) days, p=0.037). Conclusion The use of an OFA was associated with a decreased consumption of morphine and shorter ICU stays. Further randomized studies are needed to confirm these results.