The effect of mannitol on postoperative renal function in patients undergoing coronary artery bypass surgery: A double-blinded randomized controlled trial.

Introduction: Mannitol, an osmotic diuretic solution, is commonly utilized in priming cardiopulmonary bypass (CPB) and can impact kidney function. This study was conducted to investigate the impact of mannitol use during CPB on kidney function in patients undergoing coronary artery bypass surgery.

Methods: This randomized, double-blind clinical trial studied 90 patients undergoing coronary artery bypass surgery. In the control group (n=45), the prime solution included Ringer's lactate, and in the intervention group (n=45), the prime solution had 200 ml of mannitol 20% and Ringer's lactate. A P-value<0.05 was considered significant. The primary endpoint of this study is renal function.

Results: Demographic characteristics and risk factors were not significantly different between the two groups (P>0.05). Additionally, there was no statistically significant difference between two groups in terms of CPB time, aortic cross-clamp time, length of time connected to mechanical ventilation, 30-day mortality, ICU, and hospital stay time (P>0.05). Furthermore, no statistically significant difference was observed between the two groups in serum creatinine levels (P=0.53) or BUN levels (P=0.13). The study also found no statistically significant difference in the diuresis rate between the two groups (P=0.10).

Conclusion: The present study has shown that adding mannitol to the prime has no effect on kidney function, length of time connected to mechanical ventilation, length of stay in the ICU, or 30-day mortality. Therefore, it suggests that mannitol cannot be used as a preventative strategy for acute kidney injury after cardiac surgery.