Between April 1984 and June 1990, 1,410 men reported for at least one examination. Two hundred fifteen subjects were lifetime nonsmokers and denied any history of respiratory illness or symptoms. Regression analysis restricted to these 215 subjects yielded the following equations: Predicted FVC (L) = -4.46 + 0.155 height (in) – 0.0324 age (yrs) Predicted […]
Methacholine inhalation challenge testing was performed as previously described. Solutions were aerosolized by a nebulizer (DeVilbiss 646) powered by an air compressor (DeVilbiss). All inhalations were 6-s vital capacity inhalations followed by 2 s of breathholding. Seconds were counted aloud from a digital stopwatch after careful instruction and practice. Inhalations were done seated and wearing […]
Sample The Normative Aging Study is a longitudinal cohort study of health and aging established at the Veterans Administration’s Outpatient Clinic in Boston in 1963. Volunteers were recruited by advertisement and accepted into the study only if initial health screening revealed no evidence of chronic diseases including asthma, sinusitis, hypertension, or heart disease. The initial […]
Methacholine challenge testing is currently being used as a diagnostic test for a variety of clinical indications. In patients presenting with chronic cough of uncertain cause, challenge testing has been advocated as a means to determine whether the cough is associated with airway hyperresponsiveness (“cough variant asthma”) and likely to respond to bronchodilator therapy. Methacholine […]
Respiratory system resistance, as it was measured in the present study, represented total airflow resistance of the respiratory system, also including the resistance of the endotracheal tube and ventilator equipment. At given values of lung and airways resistance, total Rrs may considerably vary breathing through different sized endotracheal tubes.- Moreover, Wright and coworkers have demonstrated […]
Precise knowledge of Rrs in patients receiving mechanical ventilation is needed for adequate clinical management. In intubated patients with normal lungs, the value of Rrs is usually less dian 4 cm H20/L/s, excluding the flow-resistive properties of the endotracheal tube and equipment. The contribution of these later components to the Rrs could be as high […]
Our general population of patients had a variable degree of airflow obstruction, the Rrs ranging between 8.96 cm H20/L/s and 44.28 cm HzO/L/s (19.66 ± 1.07 cm H20/L/s) and the expired C02 slope ranging between 0.69 mm Hg/s and 12.3 mm Hg/s (3.61 ± 0.40 mm Hg/ s). The time set for expiration in the […]