Acute respiratory failure and obesity with normal ventilatory response to carbon dioxide and absent hypoxic ventilatory drive.

We measured hypoxic and hypercapnic ventilatory drive in a 64 year old woman with acute respiratory failure, congestive heart failure and obesity when she was in remission. She had a ventilatory response to carbon dioxide (CO2) comparable to that in six obese women without hypoventilation but no ventilatory response to hypoxia or to vital capacity breaths of 15 per cent CO2 in N2. Following weight loss, her ventilatory response to CO2 increased but hypoxic ventilatory response to CO2 increased but hypoxic ventilatory drive remained absent. These findings indicate that attenuation of hypoxic ventilatory drive caused by loss of peripheral chemoreceptor function can be a predisposing factor in the development of acute respiratory failure associated with obesity.