Cardiopulmonary effects of 7.2% saline solution compared with gelatin infusion in the early postoperative period after coronary artery bypass grafting

Objective: We report a clinical study on the use of 7.2%, 2400 mOsm/L, hypertonic saline solution compared with gelatin in early postoperative period after coronary artery bypass surgery. Methods: Two groups (n = 10 each) received 5 ml/kg of either saline solution or gelatin over 1 hour. Cardiac index, central venous pressure, pulmonary capillary wedge pressure, systemic and pulmonary vascular resistance indices, arterial oxygen tension, plasma osmolarity, electrolytes, and urinary output were recorded before starting the infusion and subsequently at 10, 30, 60, 90, 120, 240 and 600 minutes. Plasma creatinine, urea, electrolytes, urinary volume, and sodium excretion were measured at 12 and 24 hours. Results: There were no significant demographic or operative differences between the groups. Patients receiving saline solution had a larger diuresis at 12 (p = 0.0008) and 24 hours (p = 0.002), with less positive balance at 12 hours (p = 0.0008), The group receiving saline solution had better cardiorespiratory recovery with shorter extubation time (p = 0.033), and earlier increase in cardiac index,vith a positive correlation between plasma sodium content and cardiac index. Maximum increase in cardiac index (+31%) occurred at 60 minutes (p = 0.025) associated with 8% increase in plasma sodium content (r = 0.51, p = 0.01), without a concomitant rise in pulmonary capillary wedge pressure. The group receiving gelatin had a linear increase in cardiac index with increasing pulmonary capillary wedge pressure, reaching +16% from baseline by 90 minutes. Compared with the gelatin-treated group, patients receiving saline solution had unchanged systemic vascular resistance index hut a significantly lower pulmonary vascular resistance index with a negative correlation to plasma sodium content, There was no difference in levels of urea and creatinine. No side-effect attributable to the use of saline solution was observed.