Role of oxygen and continuous positive airway pressure therapy in chronic obstructive pulmonary disease patients with nocturnal oxygen desaturation

Introduction Sleep has a significant effect on respiration, even in healthy individuals. Breathing difficulties in chronic obstructive pulmonary disease (COPD) patients during sleep are one of the most common symptoms in these patients. Nocturnal desaturation may occur in COPD in the absence of severe daytime hypoxemia. Nocturnal desaturation may contribute to the development of pulmonary hypertension, nocturnal cardiac arrhythmias, and death during sleep. However, the optimal treatment for patients with isolated nocturnal hypoxemia remains uncertain. Aim of the work The aim of this study was to assess the role of oxygen and continuous positive airway pressure (CPAP) therapy in COPD patients with nocturnal oxygen desaturation (NOD). Patients and methods This study was conducted on 40 male COPD patients. The included patients were classified into two groups: group 1 included normoxic or mildly hypoxic patients with day time SpO 2 ≥91% defined as NOD by fall of greater than 4% from awake SpO 2 , and group 2 included moderate and severely hypoxic patients with daytime SpO 2 ≤90% who showed a pulse oximetric plot with at least 5 min with SpO 2 ≤90% and a peak of SpO 2 ≤85% and were considered as nocturnal desaturator. The two groups were subjected to full history taking, clinical examination, the Epworth sleepiness scale, anthropometric measurements, pulmonary function tests (spirometry), radiological examination using chest radiograph, and SpO 2 using pulse oximetry. SpO 2 evaluation using pulse oximetry was carried out for four nights: the first night while breathing room air, the second night while giving low-flow humidified oxygen (2 l/min) overnight, the third night with patients on noninvasive ventilation using autoset CPAP mask, and the fourth night with patients on noninvasive ventilation using autoset CPAP mask with low-flow humidified oxygen (2 l/min). Results The included patients had moderate, severe, and very severe COPD according to the GOLD spirometric classification. The highest mean value of oxygen saturation was seen in cases that received CPAP with oxygen, followed by cases that received low-flow humidified nasal oxygen, and the lowest mean value was on CPAP. In group 1, there was no significant difference between mean values of oxygen saturation on oxygen and CPAP, but there was a highly significant difference between mean values of oxygen saturation on oxygen and CPAP with oxygen, as well as on CPAP and CPAP with oxygen. In group 2, there