Effects of Liberal Versus Restrictive Fluid Therapy on Renal Function Indices in Laparoscopic Bariatric Surgery

BACKGROUND: Earlier studies have suggested the liberal administration of fluids in favor of reducing the risk of rhabdomyolysis in obese patients, but the results are conflicting. OBJECTIVES: The present study aimed at comparing the effects of liberal and restrictive fluid therapy on renal indices in laparoscopic gastric bypass surgery. METHODS: In a double-blinded randomized clinical trial, 72 candidates of bariatric surgery were randomly assigned into two groups of restrictive and liberal fluid therapy. Indices, including BUN, creatinine, creatine kinase, GFR, and urine output were measured before and 24 hours after the surgery. The clinical trial was registered at IRCT.ir under code IRCT20170109031852N3. RESULTS: There was no significant difference in BUN, creatinine, creatinine kinase, and GFR indices between the two groups of liberal and restrictive fluid therapy both before and 24 hours after surgery (P > 0.05). Intragroup comparisons before and after surgery revealed that BUN decreased in both groups after the surgery (P < 0.05). Also, creatinine and GFR values improved in patients who received a liberal fluid regimen, whereas these indices remained statistically unchanged in the restrictive group before and 24 hours after the surgery (P > 0.05). CONCLUSIONS: Two methods of liberal and restrictive fluid therapy have comparable effects on traditional renal functional indices in laparoscopic bariatric surgery. The clinical significance of observed differences in outcomes should be investigated in further studies. The use of early biomarkers of acute kidney injury is warranted.