Mismatching of ventilation and blood flow (ventilation perfusion inequality [Va/Q]) within diseased lungs is the most common cause of hypoxemia. Although it is not clear from our data which of pentoxifyllines numerous attributes is responsible for the observed improvement, they are consistent with several of the reported effects on the circulation, described below.
The action of pentoxifylline on the rheologic properties of blood and its use in the treatment of peripheral vascular disease have been reviewed by Muller. Pentoxifylline appears to improve peripheral circulation, and thereby peripheral gas exchange, by several mechanisms that reduce blood viscosity. This includes (1) increasing red blood cell deformability, (2) inhibiting platelet aggregation, […]
There was a significant increase in the healthy groups exercise Deo (Fig 3), increasing from an average baseline of 36.3 ±3.1 to a maximum of 41.8 ±3.5 ml/min/mm Hg (p<0.001). It then returned toward baseline over the following six weeks. The healthy groups stress test duration, exercise ventilation, heart rate, and peak oxygen consumption were […]
The patients with COPD ranged from moderately impaired (FEV, = 50 percent predicted, Deo = 17 ml/ min/mm Hg) to severely impaired (FEV\<50 percent predicted, Dco<12 ml/min/mm Hg). There were no significant differences between the treatment and control groups with respect to MEFV parameters, residual volume, heart rate, oxygen saturation, or diffusing capacity (Table 1). […]
The patients with COPD underwent individualized stress test protocols because they were unable to perform the standard Bruce protocol in which belt speed and inclination are both incremented by a specified amount every three minutes. The individualized protocols began with three minutes of walking at a pace evaluated by the subject as slow. (This speed […]
Informed consent was obtained from 14 patients with COPD who were referred to this study by their physician and from six healthy nonsmoking volunteers obtained from laboratory personel. All patients with COPD had been heavy smokers but all had stopped a minimum of five years earlier; none of the healthy group was a smoker. Each […]
Pentoxifylline is a trisubstituted xanthine derivative designated chemically as l-(5-oxohexyl)-3, 7-di- methylxanthine with rheologic and vasomotor effects. It has been shown to decrease blood viscosity by increasing erythrocyte deformability, reducing platelet aggregation, and promoting thrombolysis. It also causes vasodilation. The drug is currently used in patients with peripheral vascular disease to increase blood perfusion and […]