Effect of Continuous Positive Airway Pressure Therapy in Patient with Obstructive Sleep Apnea and Pulmonary Hypertension: A literature review.

Patients with obstructive sleep apnea (OSA) and pulmonary hypertension (PH) have a reduced functional capacity and potential survival. Continuous positive airway pressure (CPAP) is the primary treatment for OSA, and this improves sleep parameters, functional activity, and possibly pulmonary artery pressures (PAPs). This literature review summarizes the available studies that have measured changes in PAPs in patients with sleep apnea following the institution of CPAP. The PubMed.gov database was searched with a combination of keywords including: "Pulmonary Hypertension," "Obstructive Sleep Apnea," and "Continuous Positive Airway Pressure." Specific inclusion and exclusion criteria were applied to select prospective studies, and data were carefully extracted from each study. Seven unique studies were identified from a list of 272 search results. The studies included a range of CPAP treatments; all showed significant improvement in PAP. The average improvement in PAP across all studies when weighted for a number of participants was 9.33 ± 7.71 mm Hg. This systematic literature review demonstrates that CPAP treatment reduces PAPs in patients with OSA. The study intervals ranged from 48 hours to 6 months to determine the effects of CPAP on PH in these patients. The literature review undertaken during the analysis of these original studies on OSA and PH provides information about vascular remodeling during OSA and the effect of apnea on O2 saturation, intrathoracic pressure swings, and sympathetic surges post apnea. Patients with OSA frequently have significant comorbidity, including hypertension, obesity, and overlap syndromes with other pulmonary disorders and/or cardiac disorders. This comorbidity increases the complexity of management and likely contributes to poor outcomes. The gold standard for making a diagnosis of PH requires right heart catheterization, but practical issues dictate the need for frequent echocardiograms to evaluate right ventricular systolic pressures and right atrial and ventricle chamber sizes. A better understanding of the association between OSA and PH and its treatment with CPAP will require long-term perspective studies.