Effects of mannitol on cardiac function and postoperative arrhythmias after coronary artery bypass grafting: a randomized controlled trial.

Objective: Postoperative cardiac dysfunction and arrhythmias are significant complications following cardiac surgery, frequently resulting in increased mortality, longer hospital stays, higher healthcare costs, and diminished patient quality of life. This study investigates the effects of mannitol on cardiac function and the incidence of postoperative arrhythmias after coronary artery bypass grafting (CABG).

Methods: In a single-center, double-blind, randomized controlled trial, ninety patients undergoing elective on-pump CABG were randomly assigned (1:1) to receive either 200 mL of mannitol 20% (n = 45) or 200 mL of lactated Ringer's solution (n = 45) during cardiopulmonary bypass priming. Postoperative assessments included cardiac enzyme levels (creatine phosphokinase, creatine kinase-MB isoenzyme, and cardiac troponin I), incidence of arrhythmias (atrial fibrillation, ventricular fibrillation, ventricular tachycardia), and left ventricular ejection fraction. Statistical significance was defined as a p-value < 0.05.

Results: No significant differences were observed between the mannitol and control groups in baseline demographics or clinical risk factors (p > 0.05). Left ventricular ejection fraction was similar between the groups (45.22 ± 9.82 in the mannitol group vs. 42.66 ± 7.94 in the control group; p = 0.178). Atrial fibrillation occurred in 9 of 45 patients (20%) in the mannitol group and 12 of 45 (26.7%) in the control group (p = 0.309). Ventricular tachycardia was observed in 2 of 45 (4.4%) vs. 4 of 45 (8.9%) patients, respectively (p = 0.338). Thirty-day mortality was 2 of 45 (4.4%) in the mannitol group and 1 of 45 (2.2%) in the control group (p = 0.50). Cardiac enzyme levels (CPK, CK-MB, and cTnI) showed no significant differences between groups (p > 0.05). However, ventricular fibrillation occurred in 2 of 45 patients (4.4%) in the mannitol group versus 8 of 45 (17.8%) in the control group, a statistically significant difference (p = 0.045).

Conclusions: In conclusion, while mannitol was associated with a lower incidence of ventricular fibrillation, this is a single-center study with limited power to detect differences in other outcomes. Further studies with larger sample sizes are needed to confirm these findings.