Association between furosemide administration and outcomes in patients undergoing cardiac surgery

Abstract Background: Furosemide is widely used during the perioperative period of cardiac surgery. But the influence of furosemide on outcomes after cardiac surgery remains uncertain. We aim to investigate the relationship between furosemide usage and clinical outcomes among cardiac surgery patients.Methods: Patients who underwent cardiac surgery were identified from MIMIC‑III database. In order to fully and comprehensively assess the influence of furosemide, we transform the total dosage of furosemide into four new variables (total dose of furosemide≥200mg, total dose of furosemide/weight, average daily dose of furosemide, and average daily dose of furosemide≥20mg/d) for further analysis. Cox and logistic regression analysis were used to evaluate the associations between five furosemide related variables and clinical outcomes of cardiac surgery accordingly. Results: A total of 6,752 cardiac surgery patients were included in this analysis. 84.0% patients have used furosemide after cardiac surgery. In the cox regression after adjusted all confounding factors, average daily dose of furosemide (HR 1.07; 95% CI 1.003-1.011; P=0.001), average daily dose of furosemide≥20mg/d (HR 2.099; 95% CI 1.221-3.606; P=0.007) and total dose of furosemide≥200mg (HR1.975; 95% CI 1.095-3.562; P=0.024) were associated with increased risk of in-hospital mortality. Total dose of furosemide (HR 1.00; 95% CI 1.000-1.001; P=0.023) and average daily dose of furosemide (HR 1.003; 95% CI 1.001-1.006; P=0.016) were associated with increased risk of one-year mortality. In the logistic regression after adjusted all confounding factors, all five variables of furosemide usage were significantly increased the risk of length of ICU stay≥3d and mechanical ventilation≥48h; total dosage of furosemide, total dose of furosemide ≥200mg, total dose of furosemide/weight were associated with a higher risk of length of hospital stay≥14d.Conclusions: We demonstrated that high dose of furosemide was associated with increased mortality and adverse outcomes among cardiac surgery patients. It suggests that high-dose furosemide should be cautiously used in cardiac surgery patients.