Comparison of the acute hemodynamic effects of hypertonic or colloid infusions immediately after mitral valve repair

Objective: To determine the acute hemodynamic effect of hypertonic saline a nd/or colloid solutions as volume resuscitation in postoperative mitral val ve repair patients. Design: Prospective, randomized trial. Setting: Postoperative cardiac intensive care unit of Broussais Hospital. Patients: Twenty-six patients who underwent mitral valve repair were prospe ctively studied. Two patients were excluded during the study. Interventions: During the immediate postoperative period, when wedge pressu re decreases to <8 mm Hg, patients were randomly assigned to receive 250 mt of either hypertonic saline 7.2%-hydroxyethyl starch 6% (molecular weight, 200,000; hydroxyethylation ratio, 0.5) solution (HS-HES group), hypertonic saline 7.2% solution (HS group), or hydroxyethyl starch 6% solution (HES g roup). The infusion was completed within 15 mins. No additional volume was infused throughout the study. Measurements and Main Results: Standard hemodynamic measurements and echoca rdiographic data demonstrated that HS-HES and HS induced a higher increase in left ventricular end-diastolic area than HES. In the HS-HES and HS group s, systemic vascular resistances decreased significantly and end-systolic a rea tended to decrease. In the HES group, systemic vascular resistances did not change and end-systolic area tended to increase. Accordingly, ejection fraction increased significantly by 21% and 18% with HS-HES (from 50.5 +/- 5.5 to 61.2 +/- 4.8) and HS (from 49.7 +/- 3.6 to 58.8 +/- 3.3), respectiv ely, and did not change with HES. A major increase in cardiac index was obs erved after hypertonic solutions infusion, from 2.9 +/- 0.3 to 4.1 +/- 0.4 L/min/m(2) in the HS-HES group and from 2.7 +/- 0.3 to 3.8 +/- 0.4 L/min/m( 2) in the HS group. Then, cardiac index progressively returned to baseline values within the 3 hrs after the infusion. No significant difference was o bserved between HS-HES and HS. in these groups, plasma sodium increased sig nificantly after the infusion and remained higher than baseline values thro ughout the study. Adverse events were observed only with hypertonic solutio n administration: hypotensive episodes, sudden increases in pulmonary capil lary wedge pressure, and ventricular arrhythmias. These side effects are li kely attributable to a too-high dose and/or rate of infusion. All patients included in the study were discharged from the hospital before the 10th pos toperative day. Conclusion: We conclude that in patients who have undergone mitral valve re pair, postoperative infusion of hypertonic saline solutions increases left ventricular preload and left ventricular ejection fraction. The use of thes e hypertonic solutions may be of interest in patients with valvular cardiom yopathy. A titrated dose and a low rate of infusion may substantially impro ve the safety.