Sufficient indication of nocturnal oxygen saturation and breathing pattern in COPD patients, from a single night's study

摘要

Overnight studies in patients with chronic obstructive pulmonary disease (COPD) and daytime hypoxia are performed to record the degree of nocturnal hypoxaemia and to prescribe the proper flow of oxygen supplementation needed for maintaining normoxia (0.5-5.0 1 min~(-1)). Nocturnal studies are also performed in COPD patients with daytime normoxia who are suspected to have nocturnal hypoxaemia, e.g. because of the presence of secondary polycythaemia or pulmonary hypertension. It is quite common to perform duplicate studies since a first-night effect in EEG variables has been shown in normal subjects. However, little is known about the impact of this first-night effect on nocturnal oxygen saturation (SaO_2) and breathing in COPD patients. The aim of the present study is to determine if the study of a single night is representative and sufficient for clinical purposes.