Arterial Blood Gases and Pulmonary and Systemic Arterial Pressure During Sleep in Chronic Obstructive Pulmonary Disease

Abstract

In order to determine the effects of sleep on arterial blood gas tensions, as well as pulmonary and systemic hemodynamics in patients with chronic obstructive pulmonary disease (COPD), blood gases and pulmonary and systemic arterial pressures were measured during monitored sleep in 12 patients suffering from COPD. Alveolar hypoventilation and pulmonary hypertension progressively worsened from wakefulness through the successive stages of slow-wave sleep and were significantly aggravated during REM sleep. The mean pulmonary arterial pressure increased from an average value of 37 mm Hg in wakefulness to 55 mm Hg during REM sleep. The Paco₂ values increased from 49.7 to 57.4 mm Hg, and Pao₂ decreased from 56.2 to 42.8 mm Hg. Maximum increase of Paco₂ and maximum decrease of Pao₂ during sleep were significantly greater in COPD patients than in a control group of normal subjects. Systemic arterial pressure decreased during sleep, but not significantly. In patients with COPD, sleep-and particularly REM sleep-negatively affects alveolar ventilation and pulmonary pressure. These patients may therefore be predisposed to attacks of right ventricular cardiac failure during sleep.