Effect of Different Doses of Dexmedetomidine on Atrial Fibrillation in Adults After Cardiac Surgery.

Abstract: In this study, we compared the effects of various doses of dexmedetomidine on the incidence of atrial fibrillation (AF) after cardiac surgery in adults. A total of 224 adult patients who underwent elective cardiac surgery were randomly assigned to two groups. The DEX0.5 group received a continuous infusion of dexmedetomidine at a rate of 0.5 μg·kg⁻ 1 ·h⁻ 1 , while the DEX1 group received it at a rate of 1 μg·kg⁻ 1 ·h⁻ 1 during the induction of anesthesia, which was maintained for 24 hours. The primary outcome was the incidence of AF, while the secondary outcomes included other tachyarrhythmias, bradycardia, hypotension, duration of mechanical ventilation, time spent in the cardiac care unit, and length of hospitalization. A total of 101 patients were included in the DEX0.5 group, while 104 patients were included in the DEX1 group. The incidence of AF was significantly lower in the DEX1 group compared with the DEX0.5 group (10.6% vs. 21.8%, P = 0.029). In addition, the duration of mechanical ventilation was shorter in the DEX1 group than in the DEX0.5 group (8.9 vs. 15.2 hours, P = 0.018). Logistic regression analyses were conducted to investigate the factors influencing AF. The results indicated that the dose of dexmedetomidine was the only independent predictor (odds ratio = 0.394, 95% confidence interval 0.172 to 0.903, P = 0.028). Compared with a continuous infusion of 0.5 μg·kg⁻ 1 ·h⁻ 1 , this study suggested that administering dexmedetomidine at a dose of 1 μg·kg⁻ 1 ·h⁻ 1 for 24 hours is effective in reducing the incidence of AF after cardiac surgery.