Chest
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The cardiopulmonary effects of conventional controlled mechanical ventilation (CMV), high frequency controlled mechanical ventilation (HFV), and intermittent mandatory ventilation (IMV) were compared in nine patients with ischemic left ventricular dysfunction and pulmonary edema. Ventilatory support during IMV and CMV was adjusted by changing the ventilator rate while tidal volume was maintained at 12 ml/kg. HFV was produced at a frequency of 100 cycles/min and an I/E ratio of 1:2. ⋯ Arterial blood oxygenation, heart rate, vascular pressures, cardiac output, and myocardial ischemia were unaffected by the changes in ventilation. Decreased arteriovenous oxygen content difference (p less than 0.05) and increased mixed venous oxygen content (p less than 0.05) suggested improved systemic blood flow during IMV. Controlled ventilation by conventional means or with a high frequency technique had no detectable advantage over partial ventilatory support with IMV during cardiopulmonary failure stabilized with vasoactive therapy and continuous positive airway pressure.
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Twenty-one patients on mechanical ventilators for greater than 48 hours who had new localized infiltrates were evaluated using a quantitative culture technique of the involved lung compared to the non-involved lung. Based on the clinical course, response to antibiotics, or subsequent analysis of pathologic specimens, eight patients were felt to have acute bacterial pneumonia, while the remaining 13 were felt to have an alternative cause of their infiltrate. Cultures of the protected brush specimen of the involved lung in all eight cases of bacterial pneumonia had one or more organisms grown at a greater than 100 colony forming units (cfu) per ml while only one of the 13 cases of non-pneumonia had a culture from the involved area having greater than 100 cfu per ml (p less than 0.001). The non-involved area always grew fewer organisms than the involved area, and in 16 cases, there was no growth from the specimen obtained from the non-involved area.
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Retracted Publication
Age and cardiac surgery. Influence on extravascular lung water.
This study was designed in order to evaluate the influence of advanced age on extravascular lung water (EVLW) content. Forty patients undergoing aortocoronary bypass grafting were prospectively divided into two groups according to age below 45 years (group 1; n = 20) and above 65 years (group 2; n = 20). The EVLW was measured using the double indicator dilution technique with indocyanine green as the nondiffusible indicator. ⋯ Simultaneously, PaO2 was decreased (-114 mm Hg) and intrapulmonary shunt fraction (Qs/Qt) was increased only in this group. Within the next five hours after ECC, lung water returned nearly to baseline values and pulmonary function was normalized. It is concluded that increasing age was associated with a transient increase in EVLW after ECC due to a more pronounced fragility of the pulmonary endothelial membrane or/and to depressed left ventricular performance.