SNaPP Study

Progress

We completed recruitment of 3,500 patients on 3 July 2025 (23 months and 14 days) at 44 sites in Australia, Aotearoa New Zealand and Hong Kong. This is nearly a year ahead of schedule. Three-month follow-up will be completed on 3 October 2025. We anticipate publication of the main results in a general medical journal in 2026. 

We designed a large simple trial investigating an interesting and important research question. Our trial had broad eligibility criteria, simple trial processes and a user-friendly database. We credit the rapid completion of the trial to the experience and expertise of our trial coordination team at the University of Melbourne; the extensive networks of sites and investigators created and supported by the ANZCA Clinical Trials Network; the dedication and hard work of our site investigators and trial coordinators, and the willingness of our patients to participate in the trial. 

Summary 

Study summary
The SNaPP Study is a multicentre, double-blind, randomised clinical trial examining the effect of reversal of neuromuscular blockade on postoperative outcomes. Adult patients having abdominal or thoracic surgery under general anaesthesia will be randomised to sugammadex or neostigmine for reversal of neuromuscular blockade. The primary outcome is a composite of death or postoperative pulmonary complications up to hospital discharge (or postoperative day 7 if still in hospital).

Eligibility
Patients aged 40 years and over, scheduled for abdominal or thoracic surgery under relaxant general anaesthesia with an endotracheal tube, with expected operative time of ≥2 hours and hospital stay ≥1 postoperative night.

Study intervention
Sugammadex or neostigmine for reversal of neuromuscular blockade.

Primary endpoint
A composite of death or postoperative pulmonary complications up to hospital discharge (or postoperative day 7 if still in hospital).

Secondary endpoints
Secondary endpoints include components of the composite primary outcome, postoperative nausea and vomiting, unplanned ICU/HDU admission, days alive and at home, and change in health-related quality of life. Exploratory endpoints include duration of post anaesthesia care unit stay, airway instrumentation in the post anaesthesia care unit, change in quality of recovery score, change in frailty and severity of postoperative pulmonary complications. A health economic analysis is also planned.

Safety endpoints
A comprehensive set of events will be recorded as trial safety endpoints.

Sample size
3,500 patients.

Study duration
Four years.

Funding 

Medical Research Future Fund grant $2,948,208.65 (2023-2027)
The Australian and New Zealand College of Anaesthetists Foundation (2020) (CTN pilot study) $10000

Operations committee

Professor Kate Leslie AO FAHMS
Professor David Story
A/Professor Jai Darvall
Professor Philip Peyton
Ms Sofia Sidiropoulos

Collaborators

The University of Melbourne (Administering institution)
Australian and New Zealand College of Anaesthetists Clinical Trials Network (ANZCA CTN)

Endorsements

Australian and New Zealand College of Anaesthetists Clinical Trials Network (2020).

Trial registration

ANZCTR identifier: 12623000394640

Participating hospitals

Get in contact

Please email Sofia Sidiropoulos for any further information about the SNaPP Study.

Publications

Leslie K, Chan MTV, Darvall JN, et al. Sugammadex, neostigmine and postoperative pulmonary complications: an international randomised feasibility and pilot trial. Pilot Feasibility Stud 2021; 7: 200.