The American review of respiratory disease
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Am. Rev. Respir. Dis. · Oct 1985
Comparative StudyComparative effects of aminophylline on diaphragm and cardiac contractility.
The mechanisms by which aminophylline increases inspiratory muscle contractility are unclear. The present study compared the effects of aminophylline on cardiac as well as on diaphragm contractility and examined the interaction of aminophylline with verapamil, a calcium channel-blocking agent, on both types of muscle. Experiments were performed in mongrel dogs anesthetized with pentobarbitone. ⋯ Aminophylline increased both peak LV pressure and dPv/dt. The magnitude of the cardiac response was greater than the diaphragmatic response. Subsequent verapamil infusion completely reversed the effects of aminophylline on LV contractility but had only a small effect on diaphragm contractility.(ABSTRACT TRUNCATED AT 250 WORDS)
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Am. Rev. Respir. Dis. · Oct 1985
Intermittent positive-pressure hyperventilation with high inflation pressures produces pulmonary microvascular injury in rats.
The mechanisms by which intermittent positive-pressure ventilation with high inflation pressure (HIPPV) induces pulmonary edema remain uncertain. In this study we investigated the physiologic and anatomic changes related to HIPPV at 45 cmH2O peak inspiratory pressure in rats. Edema was quantified by the extravascular lung water obtained from postmortem weighing and by 22Na distribution space. ⋯ Additional anatomic damage appeared including epithelial lesions and hyaline membranes. Thus, HIPPV edema presents all the features of high permeability edema. These results may be of concern in the ventilatory management of patients with acute respiratory failure in order to avoid additional damages induced by local overinflation.