Effect of propranolol on respiratory function and exercise tolerance in patients with chronic obstructive lung...

Ten patients with chronic obstructive lung disease (COLD) (group 1) and five patients with combined COLD and cardiac disease (group 2) were studied at rest and during exercise after an intravenous (IV) slaine control followed by IV propranolol (0.2 mg/kg). During rest propranolol did not alter significantly measurements of lung volume in groups 1 or 2. Following propranolol the mean airway resistance (AR) in group 1 increased from 4.49 to 5.2 cm H2O/L/sec (P smaller than 0.02) and airway conductance (Gaw) decreased from 0.28 to 0.24 L/sec-1 cm. H2O1 (P smaller than 0.02). In group 2 following propranolol, the mean AR increased from 3.60 to 4.67 cm H2O1 (P smaller than 0.05), and Gaw decreased from 0.30 to 0.23 L/sec-1/cm H2O1 (P smaller than 0.05). During exercise, from control to propranolol, the heart rate (HR), blood pressure (BP), and heart rate blood pressure (HR x BP) decreased significantly for both groups 1 and 2 except for the systolic pressure in group 2. The duration of exercise and exercising PO2 were not significantly altered from control to propranolol in groups 1 and 2, indicating that the small but statistically significant changes in AR and Gaw did not interfere with symptom tolerated maximal exercise in these patients and were therefore not clinically important.