Left ventricular function during weaning of patients with chronic obstructive pulmonary disease

Abstract

Objective: Determine the evolution of left ventricular ejection fraction during weaning. Design: Prospective study. Setting: Intensive care unit of a university teaching hospital. Patients and participants: 12 consecutive mechanically ventilated patients, without documented coronary artery disease, suffering from acute exacerbation of chronic obstructive pulmonary disease and able to be weaned. Measurements and results: Left ventricular ejection fraction was determined during mechanical ventilation, inspiratory pressure support (10 cmH2O) and spontaneous ventilation with constant inspiratory oxygen fraction using technetium99m radionuclide angiography. Spontaneous ventilation induced a significant decrease in left ventricular ejection fraction from 54.5±12.4 to 47.0±13% (p<0.01). Inspiratory pressure support induced a slight but non-significant decrease in left ventricular ejection fraction from 55.0±12.1 to 50.3±12.4%. Left ventricular ejection fraction was homogeneously reduced by spontaneous ventilation without patent regional wall motion abnormalities of the left ventricle. Myocardial201thallium imaging performed 15 min after weaning showed a normal perfusion in the left ventricle anterior and posterior free wall. Conclusion: Weaning of patients suffering from chronic obstructive pulmonary disease without coronary artery disease induced a significant reduction in left ventricular ejection fraction. The non significant decrease in left ventricular ejection fraction observed with inspiratory pressure support suggested that our results might be explained by a weaning induced increase in afterload. © 1994 Springer-Verlag.