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The aim of this study was to compare the haemodynamic effects of a 45-min session of two modalities of non-invasive positive pressure ventilation (nPPV), by means of cardiac echo-Doppler and right heart catheterization, in chronic obstructive lung disease (COPD) patients with chronic respiratory insufficiency. Fourteen patients with stable COPD (11 males, mean age 62.9 ± 9.8 years) underwent right heart catheterization using a floating Grandjean catheter and simultaneous echo-Doppler measurements before and during two randomly applied 45-min ventilatory sessions, consisting of nasal intermittent positive pressure ventilation in assist/control mode (nIPPV) and nasal pressure support ventilation (nPSV). Blood gases improved significantly during both modalities of ventilation. A significant increase during ventilatory sessions was found in invasive pulmonary right atrial pressure and cardiac output. A statistically significant decrease was found in the flow velocity peak of the superior vena cava and hepatic vein, and in systodiastolic flow velocity integral of the superior vena cava and hepatic vein. The inferior vena cava collapsibility index also decreased significantly during both ventilations. Right atrium diameter and area significantly decreased while right ventricular diameter significantly increased. The echo-Doppler cardiac output decreased significantly while systolic pulmonary artery pressure increased. A short session of both nIPPV and nPSV even without PEEP can induce significant haemodynamic changes in patients with stable COPD. Two-dimensional Doppler echocardiography is a non-invasive device with sufficient reliability to monitor the haemodynamic effects of nPPV. Further studies are needed to assess the effects of nPPV on vascular peripheral flows.

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Thirty patients with stable chronic obstructive lung disease (COLD) underwent an echo-Doppler examination before and during right heart catheterization. No statistically significant differences between observations for any of two-dimensional echo-Doppler parameters were found. The measurement of all parameters taken during the catheterization correlated better with mean pulmonary artery pressure (mPAP) than those taken before. This difference was most evident for the isovolumetric acceleration time (r = 0.71 before versus r = 0.85 during the catheterization) and relaxation time (r = -0.75 before versus r = -0.87 during the catheterization). The multiple correlation coefficient for all measured parameters and mPAP was 0.83 before and 0.92 during the catheterization. In conclusion, in patients with COLD, it appears possible to get reliable information about PAP using noninvasive techniques.