Perioperative intravenous fluid and chronic kidney disease: long-term follow-up of the Restrictive versus Liberal Fluid Therapy in Major Abdominal Surgery (RELIEF) randomised trial.

Abstract

The Restrictive versus Liberal Fluid Therapy in Major Abdominal Surgery (RELIEF) randomised trial found that a restrictive intravenous fluid regimen increased the risk of acute kidney injury (AKI) after major abdominal surgery. We examined whether AKI after restrictive fluid therapy increased the risk for chronic kidney disease (CKD). We conducted long-term follow-up between 90 days and 48 months after surgery in RELIEF participants randomly assigned to a restrictive vs liberal fluid regimen, from May 2013 through September 2016. The primary outcome was incident or progressive CKD (stage ≥3), including worsening by ≥1 CKD stage in participants with preoperative CKD stage ≥3. Secondary outcomes included lowest recorded estimated glomerular filtration rate (eGFR) and maximal change in eGFR from baseline. Long-term follow-up data were obtained for 1670/2983 participants (mean age 69 (range: 58-75)yr; 47% females) included in the modified intention-to-treat analysis of the original RELIEF trial. The primary analysis was performed for 754 (49.6%) assigned to a restrictive fluid regimen and 766 (50.4%) assigned to a liberal fluid regimen. The incidence of new or worse CKD ≥ stage 3 did not differ between 422/754 (56%) participants assigned to restrictive fluid therapy, compared with 409/766 (53.4%) participants who received liberal fluid therapy (adjusted odds ratio 1.13 [95% CI 0.91-1.41]). These findings remained unaltered in sensitivity analyses. There were also no differences for eGFR secondary outcomes. Within the limits of this post hoc analysis, no difference was found in the incidence of new or progressive CKD was not related to a restrictive perioperative fluid regimen. ClinicalTrials.gov (NCT01424150).