Feasibility and safety of intravenous tolvaptan administration immediately upon ICU admission after cardiac surgery with cardiopulmonary bypass

Purpose Tolvaptan sodium phosphate (TSP; Samtas ® , Otsuka Pharmaceutical, Tokyo, Japan) is a novel intravenous aquaretic diuretic; however, evidence for its use in patients after cardiac surgery is limited. We evaluated the early postoperative administration of TSP in patients who underwent cardiac surgery. Methods We enrolled 91 patients who underwent cardiac surgery with cardiopulmonary bypass at our institution. Of these, 46 received TSP immediately after intensive care unit admission, and 45 served as controls. After propensity score matching, 20 matched pairs were analyzed. A subgroup analysis was performed according to the renal function in TSP-treated patients. Results In the propensity score-matched cohort, the TSP group showed a trend toward adequate early postoperative urine output and a gradual negative fluid balance. Regarding safety, electrolyte abnormalities did not increase in the TSP group. No patient in either group developed significant acute kidney injury. Similar trends were observed in patients with a reduced renal function. Conclusions In this selected cohort, intravenous TSP administration immediately upon ICU admission after cardiac surgery with cardiopulmonary bypass was feasible and not associated with any major safety concerns, including in patients with a reduced renal function. TSP also tended to reduce day-to-day fluid balance fluctuations with an adequate urine output.