Effect of Bilateral Carotid-Body Resection on Ventilatory Control at Rest and during Exercise in Man

Abstract

To investigate the role of the carotid bodies in the control of ventilation during rest and moderate exercise, seven asthmatic subjects who had undergone bilateral carotid-body resection (the barostatic reflexes remained intact) were studied while they were breathing air and hypoxic, hypercapnic, and hyperoxic gas. During breathing of air and 25 per cent oxygen, ventilation was not different between this group and control subjects either at rest or during exercise. The hyperpnea of hypoxia was absent, and the ventilatory response to increased arterial carbon dioxide tension was reduced 30 per cent after carotid-body resection. These studies indicate that ventilation with the subject breathing air during rest and steady-state exercise is not affected by the operation, the carotid bodies appear to be responsible for the hyperpnea of hypoxia, and this response is not enhanced by moderate exercise, and the ventilatory response to increased arterial carbon dioxide tension is reduced after bilateral carotid-body resection, despite lack of evidence of hypoventilation during breathing of air.