Decreased exercise hyperpnea in patients with bilateral carotid chemoreceptor resection

Exercise hyperpnea was compared in 5 asthmatics 25 yr after bilateral carotid body resection (BR), 4 others 19 yr after unilateral resection (UR), and 12 controls (C) matched for age and pulmonary flow limitation. In the BR group, ventilation rose less with exercise, mostly because BR experienced less tachypnea. End-tidal PCO2 rose 5.8 +/- 3.2 (P less than 0.05) to 46 Torr at 50 W. In UR and C the same load did not increase PETCO2 significantly (+2.1 and +1.4 Torr, respectively). Arterial-end-tidal PCO2 differences before and 15--45 s postexercise were insignificant in all three groups. Heart rate and blood pressure rose equally in the three groups, suggesting that the ventilatory effects were not secondary to blood flow differences and disclosing no evidence of baroreceptor denervation during glomectomy.