N/A
N=3,000
REstrictive Versus LIbEral Fluid Therapy in Major Abdominal Surgery: RELIEF Study
Abdominal Surgery
Bottom Line
View on ClinicalTrials.gov: NCT01424150 ↗Enrolled (actual)
3,000
Serious AEs
20.7%
Results posted
Jan 2025
Primary outcome: Primary: Disability-free Survival — 165; 172 Participants
Study Design & Population
- Study type
- Interventional
- Phase
- N/A
- Interventions
- Liberal fluid therapy (Other); Restrictive fluid therapy (Other)
- Age
- Adult, Older Adult · 18+ yrs
- Sex
- All
- Sponsor
- Bayside Health
- Primary completion
- Sep 2017
Outcome Measures
| Outcome | Result | p-value |
|---|---|---|
| PRIMARY Disability-free Survival |
165; 172 | — |
| SECONDARY Death |
96; 95 | — |
| SECONDARY Composite Septic Outcome or Death |
295; 323 | — |
| SECONDARY Sepsis |
129; 157 | — |
| SECONDARY Surgical Site Infection |
245; 202 | — |
| SECONDARY Pneumonia |
54; 57 | — |
| SECONDARY Acute Kidney Injury |
72; 124 | — |
| SECONDARY Pulmonary Oedema |
32; 20 | — |
| SECONDARY Total Duration of Time Spend in the ICU or HDU (in Days) |
1.8; 1.4 | — |
| SECONDARY Hospital Stay |
5.6; 6.4 | — |
| SECONDARY Quality of Recovery |
107; 106 | — |
| SECONDARY Anastomotic Leak |
35; 49 | — |
| SECONDARY C-reactive Protein |
133; 136 | — |
| SECONDARY mmol/L |
1.6; 1.6 | — |
| SECONDARY Total ICU Stay and Unplanned ICU Admission to ICU |
1.4; 1.8 | — |
Summary
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.
Eligibility Criteria
Inclusion criteria
- Adults (≥18 years) undergoing elective major surgery and providing informed consent
- All types of open or lap-assisted abdominal or pelvic surgery with an expected duration of at least 2 hours, and an expected hospital stay of at least 3 days (for example, oesophagectomy, gastrectomy, pancreatectomy, colectomy, aortic or aorto-femoral vascular surgery, nephrectomy, cystectomy, open prostatectomy, radical hysterectomy, and abdominal incisional hernia repair)
- At increased risk of postoperative complications, defined as at least one of the following criteria:
- age ≥70 years
- known or documented history of coronary artery disease
- known or documented history of heart failure
- diabetes currently treated with an oral hypoglycaemic agent and/or insulin
- preoperative serum creatinine >200 µmol/L (>2.8 mg/dl)
- morbid obesity (BMI ≥35 kg/m²)
- preoperative serum albumin 1.7 mg/dl)
- anaerobic threshold (if done) 12-14 mL/kg/min
Exclusion Criteria
- Urgent or time-critical surgery
- ASA physical status 5 - such patients are not expected to survive with or without surgery, and their underlying illness is expected to have an overwhelming effect on outcome (irrespective of fluid therapy)
- Chronic renal failure requiring dialysis
- Pulmonary or cardiac surgery - different pathophysiology, and thoracic surgery typically have strict fluid restrictions
- Liver resection - most units have strict fluid/CVP limits in place and won't allow randomisation
- Minor or intermediate surgery, such as laparoscopic cholecystectomy, transurethral resection of the prostate, inguinal hernia repair, splenectomy, closure of colostomy - each of these are typically "minor" surgery with minimal IV fluid requirements, generally low rates of complications and mostly very good survival.
Data sourced from ClinicalTrials.gov (NCT01424150). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication.