Table 2. Consequences of nocturnal hypoxaemia and hypercapnia in chronic obstructive pulmonary disease (COPD)
Parameter/outcomeAcute consequencesChronic consequences
Sleep structureAltered in severe COPD, but inconsistent improvement of sleep with oxygen administrationWorse sleep among pink puffers (mild desaturators) than blue bloaters (severe desaturators)
ArrhythmiasObserved during severe sleep desaturations; prevented by oxygen administrationRisk not directly documented
Pulmonary artery pressureIncreasedInconsistent finding with regard to differences between desaturators and nondesaturators
Diurnal blood gasesSimilar wake blood gas evolution among desaturators and nondesaturators; possible worsening of blood gases in severe COPD suggested by beneficial effects of ventilatory treatment
MortalitySome suggestion that death may preferentially occur at night among patients with exacerbations (not systematically evaluated)Prognosis independent of nocturnal hypoxaemia measured in stable conditions
Cardiovascular and cerebrovascular riskIncreased ventricular ectopic events during periods of hypoxaemiaIncreased, possibly as a result of increased sympathetic activity and altered peripheral vascular tone due to recurrent nocturnal hypoxia
Inflammatory mechanismsPronounced activation among desaturators
  • Data are taken from [34, 4144].