Articles: respiratory-distress-syndrome.
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Acta Anaesthesiol Scand · Nov 1994
Respiratory and haemodynamic effects of conventional volume controlled PEEP ventilation, pressure regulated volume controlled ventilation and low frequency positive pressure ventilation with extracorporeal carbon dioxide removal in pigs with acute ARDS.
The purpose of this study was to evaluate whether any benefit of low frequency positive pressure ventilation with extracorporeal carbon dioxide removal (LFPPV-ECCO2R) existed over either volume controlled ventilation (VCV) with measured best-PEEP or pressure regulated volume controlled ventilation (PRVCV) with an inspiration/expiration (I/E) ratio of 4:1, with respect to arterial oxygenation, lung mechanics and haemodynamics, in acute respiratory failure. Fifteen adult pigs were used for the study. Respiratory failure was induced by surfactant depletion by repeated lung lavage. ⋯ There was no significant difference between the modes concerning cardiocirculatory parameters. PRVCV with I/E ratio of 4:1 and LFPPV-ECCO2R proved to be better modes to achieve better gas exchange and lower PIP at lower intrapulmonary pressure amplitudes. It is concluded that PRVCV is an adequate form of treatment under these experimental conditions imitating acute respiratory failure, without necessitating other invasive measures.
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Case Reports
Prone position for ventilation in patients with severe adult respiratory distress syndrome.
We report 3 cases of severe adult respiratory distress syndrome. The patients were very difficult to oxygenate, even with the most advanced conventional mechanical ventilation techniques. ⋯ Reports of the use of the prone position for ventilation are scanty, and this is the first time it has been reported in this country. The proposed mechanisms for its effectiveness are reviewed.
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Randomized Controlled Trial Comparative Study Clinical Trial
Effect of bronchodilators on lung mechanics in the acute respiratory distress syndrome (ARDS).
The acute respiratory distress syndrome (ARDS) is a disorder of diffuse lung injury secondary to a wide variety of clinical insults (eg, sepsis) and is manifested by impaired oxygenation, pulmonary edema, and decreased static and dynamic compliance. More recently, airflow resistance has been shown to be increased in humans with ARDS. We designed a prospective, randomized, placebo-controlled, crossover trial to determine the presence and reversibility of increased airflow resistance in ARDS. ⋯ Metaproterenol tended to increase PaO2/PAO2, but had no effect on pulmonary shunt or dead space ventilation. We conclude that the increase in airflow resistance of ARDS is substantially reversed by aerosolized metaproterenol without affecting dead space. These data suggest that abnormalities of RL are at lest partially due to bronchospasm.
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Randomized Controlled Trial Clinical Trial
Influence of positioning on ventilation-perfusion relationships in severe adult respiratory distress syndrome.
In 12 patients with severe adult respiratory distress syndrome (ARDS), pulmonary gas exchange and hemodynamics were evaluated before, during, and after a 2-h period of pressure-controlled mechanical ventilation with the patient in the prone position. Ventilation-perfusion relationships (VA/Q) were assessed by a multiple inert gas elimination technique. Pressure-controlled mechanical ventilation in the prone position resulted in an overall increase (p < or = 0.05) of arterial oxygenation after 120 min (98.4 +/- 50.3 to 146.2 +/- 94.9 mm Hg). ⋯ The nonresponder group did not show any significant alteration in the distribution of VA/Q during the study. We concluded that improvement of oxygenation during pressure-controlled mechanical ventilation in the prone position is due to a shift of blood flow away from shunt regions, thus increasing areas with normal VA/Q. This redistribution of blood flow is most likely caused by a recruitment of previously ateletatic but nondiseased areas induced by altered gravitational forces.
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Comparative Study Clinical Trial
Permissive hypercapnia and intravascular oxygenator in the treatment of patients with ARDS.
This open clinical study was aimed at testing the hypothesis that an intravascular oxygenator (IVOX) may help to perform permissive hypoventilation in 10 patients with severe ARDS. After initial evaluation, we tried to reduce ventilator settings before and after IVOX implantation. Before IVOX, poor clinical tolerance and worsening oxygenation did not allow for a significant decrease in ventilator settings. ⋯ Tolerance of the IVOX device was good, but insertion of the device was followed by a significant decrease in both cardiac index and pulmonary wedge pressure. In conclusion, IVOX improves tolerance of hypoventilation by limiting hypercapnia in ARDS patients. These preliminary results must be confirmed by a randomized controlled study.