The linear and nonlinear regression techniques have been used to generate equations to predict “normal values” since Hutchinson first provided a quantitative index of pulmonary function based on measurements of vital capacity in more than 2,000 healthy men in 1846. The increasing importance of pulmonary function testing in diagnosing and managing lung disease and assessing [...]
Role of HPV During Exercise At rest, nifedipine diverted blood flow to poorly ventilated lung units (Fig 1 and 3). This observation strongly suggests release of HPV and is in keeping with previous reports in COPD. After releasing HPV, the increase in Ppa seen during exercise was blunted and the severity of pulmonary hypertension was [...]
Our study documents that exercise can improve Va/Q mismatching in COPD. In addition, it confirms that nifedipine releases HPV in these patients and lowers right ventricular afterload during exercise. To our knowledge, however, no previous information regarding the role of HPV in modulating gas exchange during exercise in COPD has yet been raised. Our results [...]
Exercise Before Nifedipine (vs Rest Before Nifedipine) Exercise Vo2 (872 ml/min) averaged 53 ±5 percent of maximal predicted. This represented a substantial level of exercise for these patients, as it is shown by the significant decrease in arterial pH and base excess (BE) (Table 2). During exercise, pulmonary hypertension became severe and both TPVR (Table [...]
Airflow obstruction was severe in all but patient 8, and all but one subject (patient 2) showed marked air trapping (Table 1). Hyperinflation was noticed only in patient 5. The Deo was reduced in four subjects (patients 2, 3, 5, and 6) (Table 1). Table 2 provides the metabolic, hemodynamic, and gas exchange data at [...]
Protocol The protocol was approved by the Hospital Clinic-Facultat de Medicina Research Committee on Human Investigations. Patients were allowed to continue taking their usual steroid regimen (if any), but treatment with all oral or inhaled bronchodilators was withdrawn 24 hours before the study. Specifically, patients were not receiving additional medication that could have either vasoactive [...]
Patients Eight male patients (x ± SEM, 62 ±1 year) with the standard clinical criteria of COPD and with previous functional confirmation of nonreversible chronic airflow limitation (FEV„ 1.15 ±0.12 L [36 ±3 percent predicted]) were selected from the outpatient clinic of our institution. None of them had clinical evidence of overt right heart failure. [...]
