The European respiratory journal : official journal of the European Society for Clinical Respiratory Physiology
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Inhaled nitric oxide (NO) causes selective pulmonary vasodilation and improves gas exchange in acute lung failure. In experimental pulmonary hypertension, we compared the influence of the aerosolized vasodilatory prostaglandins (PG) PGI2 and PGE1 on vascular tone and gas exchange to that of infused prostanoids (PGI2, PGE1) and inhaled NO. An increase of pulmonary artery pressure (Ppa) from 8 to approximately 34 mmHg was provoked by continuous infusion of U-46619 (thromboxane A2 (TxA2) analogue) in blood-free perfused rabbit lungs. ⋯ In contrast, lowering of Ppa by intravascular administration of PGI2 and PGE1 did not improve gas exchange. "Supratherapeutic" doses of inhaled vasodilators in control lungs (400 ppm NO, 30 ng x kg(-1) x min(-1) of PGI2 or PGE1) did not provoke vascular leakage or affect the physiological V'/Q' matching. We conclude that aerosolization of prostaglandins I2 and E1 is as effective as inhalation of nitric oxide in relieving pulmonary hypertension. When administered via this route instead of being infused intravascularly, the prostanoids are capable of improving ventilation-perfusion matching, suggesting selective vasodilation in well-ventilated lung areas.
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Randomized Controlled Trial Clinical Trial
Disabling dyspnoea in patients with advanced disease: lack of effect of nebulized morphine.
The purpose of this placebo-controlled, double-blind, randomized study was to assess the effect of nebulized morphine on dyspnoea perceived at rest by patients with advanced disease. Seventeen hospital in-patients with disabling dyspnoea received isotonic saline or morphine via nebulization for 10 min through a mouthpiece, combined with oxygen via nasal prongs. On four consecutive days, they were given one of the four following treatments in random order: saline with 2 L x min(-1) oxygen; 10 mg morphine with 2 L x min(-1) oxygen; 20 mg morphine with 2 L x min(-1) oxygen; and 10 mg morphine without oxygen (prongs fixed, no flow). ⋯ Sa,O2 significantly increased on the 3 days with supplemental oxygen, and remained stable on the zero flow day. Respiratory frequency significantly decreased on the 4 days, with a trend to correlation between VAS rating and parallel change in respiratory frequency (Spearman's rank correlation coefficient (r(s))=0.46; p=0.09). We conclude that the subjects benefited from saline or morphine via a placebo effect and/or a nonspecific effect, and that nebulized morphine had no specific effect on dyspnoea.
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Parapneumonic effusions account for about one third of all pleural effusions. Approximately 40% of patients with pneumonia develop a concomitant effusion, which is associated with an increased morbidity and mortality. ⋯ There is a considerable variation in the aggressiveness and course of parapneumonic effusions, and, therefore, the spectrum of the appropriate therapy may vary from a conservative approach in uncomplicated effusions to aggressive surgical intervention in advanced multiloculated empyemas. This review discusses current diagnostic and therapeutic options and offers guidelines for treating the various stages of parapneumonic effusions and empyemas.
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This study was designed to investigate the pathogenesis of chlorine gas (Cl2) induced acute lung injury and oedema. Isolated blood-perfused rabbit lungs were ventilated either with air (n=7) or air plus 500 parts per million (ppm) of Cl2 (n=7) for 10 min. Capillary pressure, measured by analysing the pressure/time transients of pulmonary arterial, venous and double (both arterial and venous) occlusions, was unchanged in both groups. ⋯ No changes were observed in the control lungs. The extravascular lung water/blood-free dry weight ratio was 8.6+/-1.6 in the Cl2 group and 4.0+/-0.5 in the control group (p<0.001), confirming that the increase in lung weight was related to accumulation of extravascular fluid. Although the alveolar flooding by oedema is explained, in part, by the Cl2-induced epithelial injury, our results suggest that Cl2 exposure induces acute lung injury and oedema due to an increased microvascular permeability.