Ventilation Perfusion Ratio
Mostrando 13-22 de 22 artigos, teses e dissertações.
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13. Perfusion/ventilation mismatch during exercise in chronic heart failure: an investigation of circulatory determinants.
BACKGROUND--The ventilatory cost of carbon dioxide (CO2) elimination on exercise (VE/VCO2) is increased in chronic heart failure (CHF). This reflects increased physiological dead space ventilation secondary to mismatching between perfusion and ventilation during exercise. The objectives of this study were to investigate the relation of this increased VE/VCO2
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14. Hypertensive pulmonary vascular disease in children. Detection by radioactive nitrogen (13N) inhalation and injection.
Regional lung function has been studied in 16 children with intracardiac shunts and a variety of associated cardiac anomalies using radioactive nitrogen (13N) and a gamma camera-computer system. The distribution and washout of inhaled 13N were usually normal. The distribution of intravenously injected 13N was often abnormal and could be related to local anat
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15. Comparison of cardiorespiratory effects of terbutaline and salbutamol aerosols in patients with reversible airways obstruction
Harris, L. (1973).Thorax, 28, 592-595. Comparison of cardiorespiratory effects of terbutaline and salbutamol aerosols in patients with reversible airways obstruction. The effects of pressurized aerosol administration of terbutaline were compared with those of salbutamol in 14 patients with at least 20% reversibility of airways obstruction. The two drugs were
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16. Continuous dual oximetry in surgical critical care. Indications and limitations.
Continuous dual oximetry combines pulse and venous oximetry to provide real-time information about oxygen utilization and pulmonary function. The authors undertook this study to examine the accuracy, utility, and limitations of the technique in surgical critical care. Twelve critically ill patients underwent placement of a modified pulmonary artery catheter
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17. Physiological effect of endobronchial radiotherapy in patients with major airway occlusion by carcinoma.
BACKGROUND: Endobronchial radiotherapy by a high dose rate remote after-loading technique (high dose rate brachytherapy) has become an established treatment for major airway occlusion by inoperable carcinoma of the bronchus. Only limited objective data on its effect on pulmonary physiology and on radiographic and bronchoscopic appearances are available. The
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18. Regional lung function in patients with hepatic cirrhosis
The lung volume at which the dependent lung zones begin to trap gas as a result of airway closure (i.e., the “closing volume”) was measured with 133Xe in 10 seated patients with hepatic cirrhosis. In all of them the closing volume was increased above normal, and in eight it was greater than the functional residual capacity, indicating the presence of air
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19. Effect of thoracentesis on pulmonary gas exchange.
The effect of thoracentesis on pulmonary gas exchange was studied in 33 patients with unilateral pleural effusions of various causes. Arterial blood gases were measured before thoracentesis and at 20 minutes, two hours, and 24 hours after the procedure. In 13 patients alveolar arterial oxygen gradient (PA-ao2), physiological dead space:tidal volume ratio (VD
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20. Determinants of Chronic Carbon Dioxide Retention and Its Correction in Humans
17 patients with chronic ventilatory failure (including 14 with chronic obstructive pulmonary disease) were studied to determine the causes of carbon dioxide retention and the chronic effect of medroxyprogesterone acetate on ventilatory drive and acid-base status. Carbon dioxide retention in patients with high mechanical loads occurred concomitantly with a h
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21. A critical threshold of exercise capacity in the ventilatory response to exercise in heart failure.
During exercise patients with chronic left heart failure ventilate more than normal individuals at the same workload; the ratio of minute ventilation to minute production of carbon dioxide (VE/VCO2) is increased. The relation between increased VE/VCO2, severity of heart failure, and exercise capacity has not been defined. VE/VCO2 was measured in 47 patients
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22. Bronchodilator aerosol administered by metered dose inhaler and spacer in subacute neonatal respiratory distress syndrome.
There is increasing evidence that bronchodilators are effective in ventilator dependent preterm infants. The effects of single doses of salbutamol (400 micrograms), ipratropium bromide (72 micrograms), and placebo (four puffs) given by metered dose inhaler and spacer (MDIS) were examined in 10 ventilated preterm infants, with a mean birth weight of 800 g at