ANZICS CTG Endorsed Study


Restrictive versus liberal fluid therapy in major abdominal surgery

Study Description

The RELIEF trial is a pragmatic international, randomized, assessor-blinded trial, of 3000 patients at increased risk of complications while undergoing major abdominal surgery.  Patients were randomised to receive a restrictive or liberal intravenous-fluid regimen during and up to 24 hours after surgery. The primary outcome was disability-free survival at 1 year. Key secondary outcomes were acute kidney injury at 30 days, renal-replacement therapy at 90 day and a composite of septic complications, surgical-site infection, or death.

During and up to 24 hours after surgery, 1490 patients in the restrictive fluid group had a median intravenous-fluid intake of 3.7 litres (interquartile range, 2.9 to 4.9), as compared with 6.1 litres (interquartile range, 5.0 to 7.4) in 1493 patients in the liberal fluid group (P<0.001). The rate of disability-free survival at 1 year was 81.9% in the restrictive fluid group and 82.3% in the liberal fluid group (hazard ratio for death or disability, 1.05; 95% confidence interval, 0.88 to 1.24; P = 0.61). The rate of acute kidney injury was 8.6% in the restrictive fluid group and 5.0% in the liberal fluid group

(P<0.001). The rate of septic complications or death was 21.8% in the restrictive fluid group and 19.8% in the liberal fluid group (P = 0.19); rates of surgical-site infection (16.5% vs. 13.6%, P = 0.02) and renal-replacement therapy (0.9% vs. 0.3%, P = 0.048) were higher in the restrictive fluid group, but the between-group difference was not significant after adjustment for multiple testing.

Among patients at increased risk for complications during major abdominal surgery, a restrictive fluid regimen was not associated with a higher rate of disability-free survival than a liberal fluid regimen and was associated with a higher rate of acute kidney injury.

Steering Committee

Steering Committee: Paul  Myles (Chair), Rinaldo Bellomo, Tomas Corcoran, Andrew Forbes, Philip Peyton,  David  Story, Christopher  Christophi, Katherine Leslie, Shay McGuinness, Rachael  Parke, Jonathan  Serpell, and Sophie  Wallace.

Administering Institution

Alfred Health and Monash University.

Sample Size

2800 patients


NHMRC Project Grant 2.38 million
Health Research Council of New Zealand NZ$770,000

Results Publication

Myles PS, Bellomo R, Corcoran T, Forbes A, Peyton P, Story D, Christophi C, Leslie K, McGuinness S, Parke R, Serpell J, Chan MTV, Painter T, McCluskey S, Minto G, Wallace S; Australian and New Zealand College of Anaesthetists Clinical Trials Network and the Australian and New Zealand Intensive Care Society Clinical Trials Group. Restrictive versus Liberal Fluid Therapy for Major Abdominal Surgery. N Engl J Med. 2018 Jun 14;378(24):2263-2274.


CTG12-02 Identifier: NCT01424150


Paul Myles (email)