Curated — reviewed periodically
Key papers
Primary literature, systematic reviews and commentary on sip til send and perioperative clear fluid fasting. Correspondence and methodological critique are listed alongside primary reports; inclusion is not endorsement. For recently indexed publications not yet reviewed here, see Latest research.
Ongoing studies
Recruiting / in progress
Comparison of sip til send with restrictive clear fluid fasting for pulmonary aspiration
Prospective multicentre observational cohort · Adult and paediatric · 45 Australian and New Zealand hospitals (protocol v2.0, September 2025)
Target cohort 250,000+ anaesthetics, designed to address the statistical power limitations of prior studies in detecting a rare outcome. As of April 2026 data from approximately 100,000 anaesthetics had been collected; no interim or final results published. A separate, smaller single-site pre/post audit from Cairns Hospital (14,197 anaesthetics) was presented as a conference abstract at the ANZCA Annual Scientific Meeting, May 2025 — a local proof-of-concept dataset, not the multicentre MARS result.
Primary studies
Published cohorts and trials
Impact of liberal preoperative clear fluid fasting regimens on the risk of pulmonary aspiration in children (EUROFAST)
Multicentre cohort · 31 European centres · 306,900 paediatric anaesthetics
Confirmed pulmonary aspiration: 1.18 per 10,000 (sip til send), 0.96 (≥1 h fasting), 1.83 (≥2 h fasting). Statistical non-inferiority reported for both liberalised regimens against the 2-hour control. Non-randomised design; authors note between-centre heterogeneity.
Association of a liberal clear fluid fasting policy with fasting duration, patient well-being and safety
Before-and-after cohort · Adult · Dutch academic centre, UMC Utrecht
Institutional policy change to allow clear fluids until transfer to theatre. Reduced fasting duration and improved patient-reported outcomes; no increase in aspiration reported. Observational design.
Effect of a liberal fluid fasting policy before surgery on the incidence of aspiration: a single-centre retrospective observational study
Retrospective cohort · Adult · 56,995 patients, same Dutch centre as above, longer follow-up
Aspiration in 21/56,995 patients (3.7 per 10,000, 95% CI 2.4–5.6); regurgitation in 73 patients; aspiration pneumonia in 7. More than 75% of patients fasted under 2 hours for clear fluids; median fast in the elective general anaesthesia subgroup was 1 hour. Reported incidence is higher than some historical series under 2-hour policies; retrospective design, single centre.
Unrestricted drinking before surgery: an iterative quality-improvement study
Iterative QI · German single centre, Bremen
Stepwise implementation of unrestricted clear fluid intake. Reports feasibility and no aspiration signal across implementation cycles.
'Sip 'til Send' at elective caesarean delivery: patient-reported and haemodynamic variables
Prospective observational · Obstetric · Single centre
Reports reduced thirst and altered pre-induction haemodynamic parameters under sip til send in an obstetric population.
Systematic reviews and meta-analyses
Synthesis across studies
Impact of preoperative fasting duration on perioperative complications in elective paediatric procedures: a systematic review and meta-analysis
Systematic review and meta-analysis · 8 studies, 1,234 children
No significant difference in gastric residual volume or gastric pH between shorter and longer clear fluid fasting groups. No increased pulmonary aspiration risk identified with clear fluid fasting ≤1 hour. PROSPERO CRD42024577954.
No association between preprocedural fasting and witnessed pulmonary aspiration: a systematic review and meta-analysis
Systematic review and meta-analysis · General preprocedural fasting, not sip til send-specific
Reports odds ratio 1.17 (95% CI 0.32–4.23) for aspiration between fasting durations compared, finding no association. Scope covers fasting duration broadly rather than sip til send specifically.
Commentary and correspondence
Editorial and methodological discussion
Comment on EUROFAST: methodology and non-inferiority interpretation
Correspondence
Raises questions on non-inferiority margins, cohort heterogeneity and residual confounding in EUROFAST. Companion reading alongside the primary report. Multiple further exchanges published through 2025–2026; no correction or retraction identified.
Preoperative fasting in paediatric anaesthesia: a movie with a predictable ending
Editorial, accompanying EUROFAST
Places EUROFAST within the longer trajectory of paediatric fasting guideline liberalisation.
Sip, don't skip: implementing 1-hour fasting in paediatric anaesthesia
Editorial
Editorial accompanying the 2026 paediatric fasting meta-analysis, addressing practical implementation considerations.
Fluid fasting before surgery: the ultimate example of medical sophistry?
Editorial
Reviews the evidentiary basis for historical fixed clear-fluid fasting intervals.
Sip Til Send: commentary from a national perspective
Commentary
Account from SipTilSend Network ANZ on the rationale for the network and practical considerations for departments considering adoption.
To drink or not to drink: a discussion paper on traditional versus newer fasting guidelines
Discussion paper, nursing perspective
Nursing-practice discussion of the transition between fixed-fasting and liberalised clear fluid protocols.
Disclaimer
Summaries on this page are abridged and may not reflect the full content, limitations or conclusions of the source publication. Readers should consult the primary source before relying on any finding. This content does not constitute medical or clinical advice and is provided for education at the reader's own risk; see the full disclaimer.