Sugammadex, neostigmine, and postoperative pulmonary complications: protocol of the SNaPP multicentre randomised controlled trial

Background: Sugammadex, a novel cyclodextrin reversal agent, reduces the incidence of residual neuromuscular block compared with neostigmine and was associated with fewer postoperative pulmonary complications in a systematic review of small randomised trials. However, evidence from a large RCT is required. Methods: We designed an international, multicentre RCT (the SNaPP study). A total of 3500 patients, aged ≥40 yr and undergoing abdominal or thoracic surgery, will be enrolled and randomly allocated in a 1:1 ratio to receive sugammadex or neostigmine for reversal of neuromuscular block, stratified by centre. The primary outcome is a composite of postoperative pulmonary complications (atelectasis, pneumonia, acute respiratory distress syndrome, aspiration pneumonitis, or a combination of these) or death until hospital discharge (or postoperative day 7 if still in hospital). Secondary outcomes are components of the primary outcome, postoperative nausea and vomiting, unplanned ICU/high-dependency unit admission, days alive and at home at 30 days, and health-related quality of life at 3 months. The trial aims to determine whether sugammadex compared with neostigmine reduces the incidence of postoperative pulmonary complications or death. Data will be analysed on an intention-to-treat basis. Ethics and dissemination: The SNaPP study is approved by the ethics committees at participating sites in Australia, Aotearoa New Zealand, and Hong Kong and is endorsed by the Australian and New Zealand College of Anaesthetists Clinical Trials Network. Participant recruitment began on 20 July 2023 and was completed on 3 July 2025. Publication of the SNaPP study results is anticipated in 2026. Clinical trial registration: ACTRN 12623000394640.