NCT01424150: RELIEF

Restrictive Versus Liberal Fluid Therapy in Major Abdominal Surgery

Completed NA Results posted Last updated 29 December 2025

What this trial tests

NA trial testing Liberal fluid therapy in Abdominal Surgery in 3,000 participants. Completed in 22 October 2017.

Timeline

1 July 2013

Primary endpoint
1 September 2017

22 October 2017

Quick facts

Lead sponsor	Bayside Health
Phase	NA
Status	Completed
Study type	INTERVENTIONAL
Allocation	randomized
Design	parallel
Masking	single
Primary purpose	supportive care
Enrollment	3,000
Start date	1 July 2013
Primary completion	1 September 2017
Estimated completion	22 October 2017
Sites	1 location across Australia

Drugs / interventions tested

• Liberal fluid therapy — full drug profile →
• Restrictive fluid therapy — full drug profile →

Conditions studied

• Abdominal Surgery — all drugs for Abdominal Surgery →

Sponsor

Bayside Health — full company profile →

Who can join

18 and older, any sex, with Abdominal Surgery. Patients with the condition only — healthy volunteers not accepted.

What's being measured

Primary outcomes are the specific endpoints the trial is designed to prove or disprove.

• Disability-free Survival
  Time frame: 1 year postoperative
  Disability-free survival up to 1 year: survival and freedom from disability. The latter is defined as a persistent (≥6 months) reduction in health status as measured by a 12-item version (12-60 points) of World Health Organisation Disability Assessment Schedule score (WHODAS) of 24 points, reflecting a disability level of at least 25% and being the threshold point between "disabled" and "not disab

Sponsor's own description

The optimal fluid regimen, haemodynamic (or other) targets and fluid choice (colloid or crystalloid) for patients undergoing major surgery are based on rationales that are not supported by strong evidence. Practices vary substantially, guidelines are vague, small trials and meta-analyses are contradictory. The strongest and most consistent evidence, and biological plausibility because of tissue edema, supports a restrictive fluid strategy. But other evidence supports goal-directed therapy, requiring additional IV fluid. There is no good evidence that use and choice of colloids improves outcome. RELIEF will study the effects of fluid restriction, and the possible effect-modification of goal-directed therapy and colloids. The first will be randomly assigned; the latter will be measured covariates dictated by local practices and beliefs.

Study Hypotheses A restrictive fluid regimen for adults undergoing major abdominal surgery leads to reduced complications and improved disability-free survival when compared with a liberal fluid regimen.

Secondary hypothesis: The effects of fluid restriction are similar whether or not goal-directed therapy is used (assessed as a statistical test of interaction). A restrictive fluid regimen will reduce a composite of 30-day septic complications and mortality.

Publications & conference data

6 peer-reviewed publications reference this trial (live from Europe PMC):

1. Restrictive versus Liberal Fluid Therapy for Major Abdominal Surgery.
   Myles PS, Bellomo R, Corcoran T, Forbes A, et al · · 2018 · cited 557× · PMID 29742967 · DOI 10.1056/nejmoa1801601
2. American Society for Enhanced Recovery (ASER) and Perioperative Quality Initiative  (POQI) joint consensus statement on perioperative fluid management within an enhanced recovery pathway for colorectal surgery.
   Thiele RH, Raghunathan K, Brudney CS, Lobo DN, et al · · 2016 · cited 112× · PMID 27660701 · DOI 10.1186/s13741-016-0049-9
3. Importance of intraoperative oliguria during major abdominal surgery: findings of the Restrictive versus Liberal Fluid Therapy in Major Abdominal Surgery trial.
   Myles PS, McIlroy DR, Bellomo R, Wallace S. · · 2019 · cited 37× · PMID 30916001 · DOI 10.1016/j.bja.2019.01.010
4. Restrictive versus liberal fluid therapy in major abdominal surgery (RELIEF): rationale and design for a multicentre randomised trial.
   Myles P, Bellomo R, Corcoran T, Forbes A, et al · · 2017 · cited 36× · PMID 28259855 · DOI 10.1136/bmjopen-2016-015358
5. Association of Obesity With Septic Complications After Major Abdominal Surgery: A Secondary Analysis of the RELIEF Randomized Clinical Trial.
   Gurunathan U, Rapchuk IL, Dickfos M, Larsen P, et al · · 2019 · cited 19× · PMID 31774526 · DOI 10.1001/jamanetworkopen.2019.16345
6. Understanding Restrictive Versus Liberal Fluid Therapy for Major Abdominal Surgery Trial Results: Did Liberal Fluids Associate With Increased Endothelial Injury Markers?
   Bihari S, Dixon DL, Painter T, Myles P, et al · · 2021 · cited 4× · PMID 33521643 · DOI 10.1097/cce.0000000000000316