No abstract

Study Objectives: We hypothesized that positional therapy would be equivalent to continuous positive airway pressure (CPAP) at normalizing the apnea-hypopnea index (AHI) in patients with positional obstructive sleep apnea (OSA). Methods: Thirty-eight patients (25 men, 49 ± 12 years of age, body mass index 31 ± 5 kg/m 2 ) with positional OSA (nonsupine AHI < 5 events/h) identified on a baseline polysomnogram were studied. Patients were randomly assigned to a night with a positional device (PD) and a night on CPAP (10 ± 3 cm h 2 o). Results: Positional therapy was equivalent to CPAP at normalizing the AHI to less than 5 events per hour (92% and 97%, respectively [p = 0.16]). The AHI decreased from a median of 11 events per hour (interquartile range 9-15, range 6-26) to 2 (1-4, 0-8) and 0 events per hour (0-2, 0-7) with the PD and CPAP, respectively; the difference between treatments was significant (p < 0.001). The percentage of total sleep time in the supine position decreased from 40% (23%-67%, 7%-82%) to 0% (0%-0%, 0%-27%) with the PD (p < 0.001) but was unchanged with CPAP (51% [36%-69%, 0%-100%]). The lowest Sao 2 increased with the PD and CPAP therapy, from 85% (83%-89%, 76%-93%) to 89% (86%-9%1, 78%-95%) and 89% (87%-91%, 81%-95%), respectively (p < 0.001). The total sleep time was unchanged with the PD, but decreased with CPAP, from 338 (303-374, 159-449) minutes to 334 (287-366, 194-397) and 319 (266-343, 170-386) minutes, respectively (p = 0.02). Sleep efficiency, spontaneous arousal index, and sleep architecture were unchanged with both therapies. Conclusion: Positional therapy is equivalent to CPAP at normalizing the AHI in patients with positional OSA, with similar effects on sleep quality and nocturnal oxygenation.

No abstract

Use of supplemental long-term oxygen therapy (LTOT) by patients with COPD is common, with more than 1 million Medicare recipients using oxygen at an annual cost of more than $2 billion. 1,2 Although current indications for LTOT are based on the results of older randomized trials, 3,4 a recent conference identifi ed uncertainties regarding LTOT in COPD, including its effi cacy in patients with more moderate hypoxemia. 1 This article reviews the available evidence regarding the effi cacy of LTOT for individuals with COPD Long-term use of supplemental oxygen improves survival in patients with COPD and severe resting hypoxemia. However, the role of oxygen in symptomatic patients with COPD and more moderate hypoxemia at rest and desaturation with activity is unclear. The few long-term reports of supplemental oxygen in this group have been of small size and insuffi cient to demonstrate a survival benefi t. Short-term trials have suggested benefi cial effects other than survival in patients with COPD and moderate hypoxemia at rest. In addition, supplemental oxygen appeared to improve exercise performance in small short-term investigations of patients with COPD and moderate hypoxemia at rest and desaturation with exercise, but long-term trials evaluating patient-reported outcomes are lacking. This article reviews the evidence for long-term use of supplemental oxygen therapy and provides a rationale for the National Heart, Lung, and Blood Institute Long-term Oxygen Treatment Trial. The trial plans to enroll subjects with COPD with moderate hypoxemia at rest or desaturation with exercise and compare tailored oxygen therapy to no oxygen therapy.

Sleep abnormalities are common in severe emphysema, and include poor sleep quality, the development of nocturnal oxygen desaturation, and the presence of coexistent obstructive sleep apnea. With lower baseline oxygenation and abnormal respiratory mechanics in patients with severe emphysema, alterations in ventilatory control and respiratory muscle function that normally occur during sleep can have profound effects, and contribute to the development of sleep abnormalities. The impact on quality of life, cardiopulmonary hemodynamics, and overall survival remains uncertain. In addition, treatment for chronic obstructive pulmonary disease and its effect on sleep abnormalities have demonstrated conflicting results. More recently, as part of the National Emphysema Treatment Trial, lung volume reduction surgery has been shown to improve both sleep quality and nocturnal oxygenation in emphysema. Although indications for performing an overnight polysomnogram in patients with emphysema have been debated, recommendations have been presented. Future studies investigating disease mechanism and response to therapy in patients with sleep abnormalities and severe emphysema are warranted.Keywords: emphysema; sleep; hypoventilation; apnea; oxygenation Patients with severe emphysema commonly have distinct abnormalities related to sleep that include poor sleep quality (1-4) and the development of nocturnal oxygen desaturation (NOD) (1,(3)(4)(5)(6)(7)(8). Patients with emphysema often complain of difficulty with initiating and maintaining sleep (3), and objective measurements have demonstrated increased sleep latency, decreased total sleep time, and an increased number of nocturnal arousals (1-4). These findings contribute to the excessive daytime sleepiness and early morning awakenings reported in these patients (9-11). As part of the National Emphysema Treatment Trial (NETT), sleep quality and nocturnal oxygenation have been examined in patients with severe emphysema who were being evaluated for lung volume reduction surgery (LVRS) (4, 12).Episodes of NOD are more pronounced during REM sleep (2, 5-7), and can develop despite an awake Pa O 2 . 60 mm Hg. Although predictors for the development of NOD have been identified (3,7,8,(13)(14)(15)(16)(17)(18), its effect on pulmonary hemodynamics and overall survival are still uncertain. In addition, patients with emphysema with coexistent obstructive sleep apnea (OSA), often referred to as the ''overlap syndrome,'' also demonstrate NOD. This review examines the physiological variables that affect sleep quality and nocturnal oxygenation in severe emphysema. In addition, therapeutic interventions, including LVRS, and their impact on sleep quality and overall survival are reviewed. Finally, limitations in the current literature and open questions that remain to be answered are discussed. PHYSIOLOGICAL ALTERATIONS DURING SLEEPVentilation is normally controlled by a combination of two systems: a metabolic system responsible for the automatic changes directly related to gas exchange, and a beha...

In smokers with OSA, increased gas trapping and emphysema as assessed by CT are associated with a decreased AHI. Along with sex and BMI, these measurements may be important in determining the severity of OSA in patients with COPD and may offer a protective mechanism in patients with more advanced disease.

No abstract

No abstract