ENOXIMONE AND ACUTE LEFT-VENTRICULAR FAILURE DURING WEANING FROM MECHANICAL VENTILATION AFTER CARDIAC-SURGERY

Objective: To evaluate enoximone, a phosphodiesterase III inhibitor, i n the treatment of left ventricular failure during the weaning of pati ents from mechanical ventilation after heart surgery. Design: Open lab el, prospective, weaning trial. Setting: Cardiothoracic surgical inten sive care unit (ICU) in a university hospital. Patients: Nine patients were studied after one or more unsuccessful attempts at weaning from mechanical ventilation due to left ventricular dysfunction. Interventi on: For each patient, two respiratory weaning attempts were studied: t he first one as a control and the second one with enoximone infused at a rate of 30 mu g/kg/min for 30 mim, then at a rate of 10 mu g/kg/min . Measurements and Main Results: Hemodynamic measurements were perform ed at the following interval times: baseline during mechanical ventila tion; during spontaneous ventilation with a T-piece for a minimum of 1 0 mine; during mechanical ventilation after the enoximone infusion for 30 mins; during spontaneous ventilation for a minimum of 10 mim with an enoximone infusion running. During spontaneous ventilation, enoximo ne increased cardiac index by 34% but mean artery, right atrial, and p ulmonary artery occlusion pressures did not change. Despite an increas e in venous admixture due to augmented cardiac index and inhibition of hypoxic vasoconstriction, no oxygen debt occurred because oxygen deli very increased. Seven of nine patients were weaned successfully from m echanical ventilation. Conclusion: Because of its positive inotropic a nd vasodilatory properties, enoximone is helpful for respiratory weani ng of patients with left ventricular failure after cardiac surgery.