Efficacy and Safety Evaluation of Tolvaptan on Management of Fluid Balance after Cardiovascular Surgery Using Cardiopulmonary Bypass.

Background: Tolvaptan is an orally administered selective vasopressin 2 receptor antagonist that promotes aquaresis. This study aimed to evaluate the efficacy and safety of tolvaptan on management of systemic fluid balance after cardiovascular surgery using cardiopulmonary bypass. .

Methods: Sixty-four patients who underwent cardiovascular surgery using cardiopulmonary bypass in our hospital were enrolled for this prospective, randomized study. These patients were divided into three groups: tolvaptan 15 mg+furosemide 20 mg (TH group), tolvaptan 7.5 mg+furosemide 20 mg (TI group), and furosemide 40 mg+spironolactone 50 mg (C group). The endpoint was safety management of systemic fluid balance using tolvaptan without renal dysfunction and electrolyte imbalance.

Results: The mean daily urine output in the TH and TL groups (2656±767 and 2505 ±684 mL) was significantly higher than that in the C group (1956±494 mL, TH vs C: p<0.01 and TL vs C: p=0.03). The lowest serum sodium level during medication in the TH group (139.3 ±2.3 mEq/L) was significantly higher than that in the C group (137.1±2.9 mEq/L, p=0.03) The lowest serum osmolality during medication in the TH group was significantly higher than that in the C group (284.8 ±4.3 vs 279.5± 6.3 mOsm/kg, p<0.01). None had critical hypernatremia, hyperosm6lality, or renal dysfunction in any. of the groups.

Conclusions: Tolvaptan exerts, a strong diuretic effect compared with conventional diuretics (furosemide and spironolactone) during the postoperative period after an operation using cardiopulmonary bypass without adverse effects on electrolyte balance and renal function.