Neural Respiratory Drive and Ventilation in Patients with Chronic Obstructive Pulmonary Disease during Sleep

摘要

Patients with chronic obstructive pulmonary disease (COPD) experience sleep-related hypoventilation . However, there is controversy as to whether this occurs due to an increase in upper airway resistance or a reduction in neural respiratory drive. Elevated neural respiratory drive in wakefulness is well documented in COPD. O'Donoghue and coworkers reported in patients with COPD that a sleep-related hypoventilation was due to increased upper airway resistance, and Ballard and coworkers reported an increase in upper airway resistance moving from wakefulness to sleep, although upper airway resistance was not consistently greater during sleep (see Figure 3 of their article ). Moreover, in healthy young adults, a poor correlation was observed between changes in ventilation and upper airway resistance. Morrell and coworkers addressed the question directly in tracheotomized subjects, confirming hypoventilation during sleep, thus excluding an obligate contribution from upper airway resistance. To further address the question, we performed diaphragm electromyography (EMG_(di)) using a multipair esophageal electrode as an index of neural respiratory drive (8-11). Some of the data have been previously reported in abstract form.