Hypertonic saline (7.5%) decreases perioperative weight gain following cardiac surgery

Objective: To compare the effects of 7.5% hypertonic saline (HS) and 0.9% normal saline (NS) on perioperative weight gain in cardiac surgical patients. Design: Prospective, randomized study. Setting: University teaching hospital. Participants: Patients (n = 72) scheduled for elective coronary artery bypass graft surgery. Interventions: Patients were randomly assigned to receive either 7.5% HS (36 patients) or 0.9% NS (36 patients) as a single dose of 4 mL/kg over 30 minutes during the postoperative rewarming phase in the intensive care unit. Measurements and Main Results: Weight gain until the first postoperative morning was significantly greater in the NS group than in the HS group (1.9 +/- 1.4 kg, median, 2.1 kg; 0.8 +/- 1.5 kg, median, 0.8 kg; p = 0.005). One-hour diuresis after the fluid infusion was significantly greater in the HS group compared with the NS group (501 +/- 282 mL and 237 +/- 173 mL; p < 0.001). In the linear regression model, the 2 most important factors affecting the perioperative weight gain were the volume of fluid infused postoperatively in the intensive care unit (4,098 +/- 916 mL in the HS group and 4,589 +/- 1,344 mL in the NS group) and the total diuresis after surgery (3,351 1,035 mL in the HS group and 2,942 846 mL in the NS group). Conclusion: HS had an intense diuretic effect, which reduced intraoperative fluid retention. This effect was confirmed by the lesser increase in body weight measured on the first postoperative morning. Copyright 2002, Elsevier Science (USA). All rights reserved.