Effects of opioid-free anaesthesia compared with balanced general anaesthesia on nausea and vomiting after video-assisted thoracoscopic surgery: a single-centre randomised controlled trial

Abstract

Objectives: Opioid-free anaesthesia (OFA) has emerged as a promising approach for mitigating the adverse effects associated with opioids. The objective of this study was to evaluate the impact of OFA on postoperative nausea and vomiting (PONV) following video-assisted thoracic surgery.

Design: Single-centre randomised controlled trial.

Setting: Tertiary hospital in Shanghai, China.

Participants: Patients undergoing video-assisted thoracic surgery were recruited from September 2021 to June 2022.

Intervention: Patients were randomly allocated to OFA or traditional general anaesthesia with a 1:1 allocation ratio.

Primary and secondary outcome measures: The primary outcome measure was the incidence of PONV within 48 hours post-surgery, and the secondary outcomes included PONV severity, postoperative pain, haemodynamic changes during anaesthesia, and length of stay (LOS) in the recovery ward and hospital.

Results: A total of 86 and 88 patients were included in the OFA and control groups, respectively. Two patients were excluded because of severe adverse events including extreme bradycardia and epilepsy-like convulsion. The incidence and severity of PONV did not significantly differ between the two groups (29 patients (33.0%) in the control group and 22 patients (25.6%) in the OFA group; relative risk 0.78, 95% CI 0.49 to 1.23; p=0.285). Notably, the OFA approach used was associated with an increase in heart rate (89±17 vs 77±15 beats/min, t-test: p<0.001; U test: p<0.001) and diastolic blood pressure (87±17 vs 80±13 mm Hg, t-test: p=0.003; U test: p=0.004) after trachea intubation. Conversely, the control group exhibited more median hypotensive events per patient (mean 0.5±0.8 vs 1.0±2.0, t-test: p=0.02; median 0 (0-4) vs 0 (0-15), U test: p=0.02) during surgery. Postoperative pain scores, and LOS in the recovery ward and hospital did not significantly differ between the two groups.

Conclusions: Our study findings suggest that the implementation of OFA does not effectively reduce the incidence of PONV following thoracic surgery when compared with traditional total intravenous anaesthesia. The opioid-free strategy used in our study may be associated with severe adverse cardiovascular events.

Trial registration number: ChiCTR2100050738.

Keywords: ANAESTHETICS; Adult anaesthesia; Thoracic surgery.