The aim of this study was to investigate the haemodynamic and endocrinological effects of noninvasive positive pressure ventilation (NIPPV).Eleven patients with oedema and recent hypercapnic and hypoxaemic worsening of a chronic respiratory insufficiency were included. Echocardiography, cardiac radionuclide assessment, blood catecholamines, salt and water handling hormones were measured at admission and discharge (long study (LS)). To discriminate between the action of NIPPV and other treatments, measurements were performed on the fourth day, for 4 h without NIPPV and 4 h with NIPPV (short study (SS)).NIPPV entailed a correction of Pa,CO 2 and an increase of Pa,O 2 in LS and SS. Oedema disappeared. Body weight decreased (from 85±42 to 81±40 kg) during LS. Systolic and mean pulmonary arterial pressure decreased in LS and SS. Right ventricular ejection fraction increased in LS. Left ventricular ejection fraction did not change. Cardiac index was normal on admission and then decreased. Natriuretic peptides and catecholamines were increased on admission, whereas plasma renin activity, aldosterone and vasopressin were normal.We suggest that in these patients, oedema can occur independently of reninangiotensin-aldosterone-vasopressin and with a normal cardiac output. Noninvasive positive pressure ventilation allowed a correction of blood gases, associated with the resolution of oedema, a decrease in pulmonary arterial pressures and an increase in right ventricular ejection fraction. Eur Respir J 1997; 10: 2553-2559 Severe chronic respiratory insufficiency often leads to pulmonary arterial hypertension and cor pulmonale, which are associated with increased mortality [1]. Peripheral oedema is often witnessed in these patients, and the traditional view has been to assume that this results from right ventricular failure and/or the increased secretion of salt and water-handling hormone [2,3]. Longterm noninvasive positive pressure ventilation (NIPPV) is effective in improving blood gases and thereby decreasing pulmonary hypertension, clearing oedema, and reducing morbidity and mortality associated with this condition [4]. Its beneficial effects on oedema could result from improved right ventricular function and cardiac output as well as a lowering of salt and water-handling hormone levels, as demonstrated during invasive mechanical ventilation [5]. However, there is a scarcity of published data on the consequences of NIPPV on pulmonary haemodynamics, ventricular function and hormonal patterns in oedematous patients with chronic respiratory insufficiency in which long-term ventilatory support is initiated.The aims of this study were, therefore: 1) to measure the haemodynamic effects of NIPPV, which would be expected to reduce pulmonary arterial pressure and improve right ventricular ejection fraction because of the correction of Pa,CO 2 and Pa,O 2 ; 2) to explore the haemodynamic and endocrine profiles of patients during a recent worsening of chronic hypercapnic respiratory insufficiency, in particular the major h...

Liver cirrhosis is sometimes associated with very severe hypoxaemia, which is thought to be the result of intrapulmonary vascular dilatations (IPVDs). These vascular abnormalities, although close to the gas exchange units, are so dilated that diffusion of oxygen molecules to their centre is impaired, causing an increase in alveolar-arterial oxygen tension difference (P(A-a)O2). On the other hand, administration of 100% oxygen provides enough driving pressure to overcome this relative diffusion defect and rules out a true intrapulmonary shunt. We report a case in which, in spite of a normal increase in arterial oxygen tension (PaO2) under 100% oxygen, exercising results in a marked impairment of oxygen exchange and a large intrapulmonary shunt. This is probably due to the increased cardiac output and preferential blood flow through these low resistance IPVDs.