Preventive Effect of Tolvaptan on Pleural Effusion after Cardiac Valvular Surgery / 日本心臓血管外科学会雑誌

ABSTRACT

Background: Post-operative fluid management after cardiac valvular surgery is very important. In our institute, carperitide 0.0125 γ was started during surgery and oral furosemide 20-40 mg/day and spironolactone 25 mg/day were started at post-operative day (POD) 1 as the standard therapy. Tolvaptan, vasopressin V2 receptor antagonist, was started when fluid retention such as pleural effusion occurred. With this strategy, the frequency of pleural drainage was more than 40%. Therefore we changed our standard therapy in February 2018. In this new standard therapy, carperitide (0.0125 γ) was started and maintained until oral intake became possible and tolvaptan 7.5 mg was started with furosemide 20 mg and spironolactone 25 mg as oral medicine usually at POD 1. In this study, whether tolvaptan prevents pleural effusion or not after cardiac surgery was examined. Subjects and Methods: Sixty-four patients were operated during February 2017 and December 2018 were included in this study. Thirty-two patients operated in the period until January 2018 served as control group and were compared with 32 patients for whom tolvaptan was started on POD 1 (tolvaptan group). Results: There was no significant difference between two groups for background, operative procedure, operation time, cardiopulmonary bypass time, aortic cross clamp time and fluid balance during procedure. Tolvaptan was given to all patients in the tolvaptan group and in 22% of patients in the control group. Oral furosemide dose (tolvaptan group 21±5 mg/day, control group 31±20 mg/day, p＝0.0112), and the frequency of patients with intravenous furosemide administration (tolvaptan group 9%, control group 44%, p＝0.0038) were significantly less in tolvaptan group. In the tolvaptan group, intravenous furosemide administrated only once in all patients, whereas the frequency of intravenous furosemide administration was 1-32 times, average 6.6 times in control group. Tolvaptan was stopped within 1 week because of too much urination in two patients and the elevation of liver enzyme in two patients without any adverse effects. Post-operative urination volume until POD 5 did not differ. In both groups, body weight increased at POD 1 and 2 and returned to pre-operative weight at POD 3. Pleural effusion was significantly less in the tolvaptan group at POD 3 (tolvaptan group none 66%, small amount 22%, moderate amount 3%, drain tube inserted 9%, control group none 16%, small amount 34%, moderate amount 13%, drain tube inserted 38%, p＝0.0003), at POD 7 (tolvaptan group none 72%, small amount 28%, vs., control group none 47%, small amount 19%, moderate amount 22%, drain tube inserted 13%, p＝0.0041) and at discharge (tolvaptan group none 94%, small amount 6%, vs., control group none 69%, small amount 22%, moderate amount 9%, p＝0.0301). The frequency of pleural drainage was also less in the tolvaptan group (tolvaptan group 9.4%, control group 44%, p＝0.0038). Conclusion: After cardiac valvular surgery, tolvaptan started at POD 1 is very effective to reduce the frequency of pleural effusion and pleural drainage, and careful checking for too much urination and the elevation of liver enzymes is mandatory.