44 7897 074717Commentary - Journal of Pulmonology and Clinical Research (2024) Volume 7, Issue 1
Osa-ph: Cpap cornerstone, oxygenâ≢s uncertain impact.
Nicolas Dubois*
Department of Pulmonary Medicine, University of Montreal, Canada
- *Corresponding Author:
- Nicolas Dubois
Department of Pulmonary Medicine
University of Montreal, Canada.
E-mail: nicolas.dubois@umontreal.ca
Received : 01-Feb-2024, Manuscript No. AAJPCR-24-175; Editor assigned : 05-Feb-2024, PreQC No. AAJPCR-24-175(PQ); Reviewed : 23-Feb-2024, QC No AAJPCR-24-175; Revised : 05-Mar-2024, Manuscript No. AAJPCR-24-175(R); Published : 14-Mar-2024 , DOI : 10.35841/aajpcr-7.1.175
Citation: Dubois N. Osa-ph: Cpap cornerstone, oxygen's uncertain impact. J Pulmonol Clin Res. 2024;07(01):175.
Introduction
The complex relationship between obstructive sleep apnea (OSA) and pulmonary hypertension (PH) represents a significant area of ongoing research and clinical challenge. These conditions are intricately linked, with OSA being a major contributor to the development and progression of PH through various pathophysiological mechanisms [2].
The core mechanisms involve intermittent hypoxia, hypercapnia, and heightened sympathetic activity characteristic of OSA [2].
Furthermore, chronic intermittent hypoxia (CIH), a hallmark of OSA, directly contributes to PH by inducing detrimental hypoxic pulmonary vasoconstriction and vascular remodeling [8].
Molecular pathways further elucidate how intermittent hypoxia drives PH through oxidative stress, inflammation, and endothelial dysfunction, revealing potential therapeutic targets [5].
Understanding these intricate links is crucial for effective diagnosis and management. Diagnostic approaches for PH in OSA patients emphasize the importance of screening for OSA in PH patients, and vice versa [4].
This reciprocal screening is vital for early detection and intervention. Comprehensive reviews synthesize information on the epidemiology, pathogenesis, and diagnostic procedures for PH originating from OSA [10].
Regarding management, continuous positive airway pressure (CPAP) remains the foundational and primary treatment for OSA-related PH [4, 7, 10]. CPAP plays a crucial role in mitigating PH progression in OSA patients by addressing the underlying sleep-disordered breathing [2].
However, the role of oxygen therapy, particularly nocturnal oxygen supplementation (NOS) or nocturnal oxygen therapy (NOT), is more nuanced and has been a subject of extensive investigation [1, 3, 9]. Several studies have explored the efficacy of nocturnal oxygen supplementation. For instance, a systematic review examined NOS for OSA-PH, finding inconsistent evidence on its ability to consistently reverse PH or improve hemodynamics long-term, despite its capacity to improve nocturnal hypoxemia [1].
Current guidelines often do not universally recommend NOS for OSA-PH without documented daytime hypoxemia, highlighting the need for more definitive research in this area [1].
Similarly, a meta-analysis on NOT for PH in OSA patients observed improved nocturnal oxygenation, but its overall impact on consistently reducing pulmonary arterial pressure or reversing PH was not statistically significant [3].
These findings suggest that more comprehensive and long-term studies are needed to establish definitive benefits [3].
Despite these findings, supplemental oxygen is considered in specific contexts. For individuals with significant nocturnal hypoxemia, co-existing Chronic Obstructive Pulmonary Disease (COPD), or when CPAP alone is insufficient, oxygen therapy becomes a supplementary role [4, 7]. The potential for oxygen therapy to lessen the adverse effects of CIH by enhancing nocturnal oxygen levels is also acknowledged [8].
Clinical reviews underscore the importance of careful patient selection for oxygen supplementation, based on documented hypoxemia and the severity of PH [6].
The current state of oxygen therapy for OSA-related PH indicates that while it improves nocturnal oxygenation, its definitive long-term benefits on PH hemodynamics still necessitate more robust clinical trials, especially within personalized medicine frameworks [9].
A multifaceted treatment approach is often advocated, combining CPAP with careful application of oxygen therapy for patients with documented hypoxemia and significant PH [10].
Therefore, an individualized treatment plan is essential, tailored to patient needs and specific clinical presentations [7].
Future research should aim to clarify the long-term impact and optimal application of oxygen therapy in this complex patient population.
Conclusion
Obstructive sleep apnea (OSA) is strongly implicated in the development and progression of pulmonary hypertension (PH), driven by mechanisms like intermittent hypoxia, hypercapnia, and heightened sympathetic activity [2, 5, 8]. Screening for both conditions is crucial for early diagnosis and tailored management [4, 6]. Continuous Positive Airway Pressure (CPAP) is the cornerstone therapy for OSA-related PH, effectively mitigating disease progression [2, 7, 10]. However, the role of oxygen therapy, particularly nocturnal supplementation, is more complex and less definitively established for long-term PH reversal or hemodynamic improvement [1, 3, 9]. While nocturnal oxygen supplementation (NOS) consistently improves nocturnal oxygenation, studies show inconsistent evidence regarding its ability to reverse PH or significantly reduce pulmonary arterial pressure over time [1, 3]. Current guidelines typically do not recommend NOS universally for OSA-PH without documented daytime hypoxemia, emphasizing the need for more robust, long-term research [1, 3, 9]. Despite these findings, supplemental oxygen is selectively used for patients with severe nocturnal hypoxemia, co-existing COPD, or when CPAP alone is insufficient, aiming to counteract the adverse effects of chronic intermittent hypoxia [4, 7, 8]. This highlights a need for careful patient selection based on individual hypoxemia and PH severity [6]. Ultimately, a multifaceted, individualized treatment approach, with CPAP as primary and oxygen therapy as a supplemental tool, is recommended, while further research is needed to fully delineate oxygen's long-term benefits on PH hemodynamics [7, 9, 10].
References
References
- Yifan H, Tianyu S, Hong L. Nocturnal Oxygen Supplementation in Patients With Obstructive Sleep Apnea and Pulmonary Hypertension: A Systematic Review. J Clin Med. 2023;12(13):4261.
Indexed at, Google Scholar, Crossref
- Sridhar RN, Sri HVP, Hari KN. Pulmonary Hypertension in Obstructive Sleep Apnea: Pathophysiology, Diagnosis, and Management. Curr Cardiol Rep. 2024;26(4):307-316.
Indexed at, Google Scholar, Crossref
- Jianying Y, Tian L, Ting H. Effect of nocturnal oxygen therapy on pulmonary hypertension in patients with obstructive sleep apnea: A systematic review and meta-analysis. J Clin Sleep Med. 2021;17(3):525-534.
Indexed at, Google Scholar, Crossref
- Yael MK, Samuel R, Andrew RS. Updates in Diagnosis and Management of Pulmonary Hypertension in Obstructive Sleep Apnea. Curr Opin Pulm Med. 2020;26(2):162-168.
Indexed at, Google Scholar, Crossref
- Meng-Wen H, Chun-Mei L, Yuan-Rong L. Intermittent Hypoxia and Pulmonary Hypertension in Obstructive Sleep Apnea: Molecular Mechanisms and Therapeutic Targets. Front Cardiovasc Med. 2023;10:1119760.
Indexed at, Google Scholar, Crossref
- Fabio G, Anna D, Nicola M. Pulmonary hypertension associated with obstructive sleep apnea: A clinical review. Minerva Medica. 2022;113(1):164-171.
Indexed at, Google Scholar, Crossref
- Yan W, Ling Z, Yi L. Treatment of pulmonary hypertension associated with obstructive sleep apnea: a review. Respir Res. 2020;21(1):210.
Indexed at, Google Scholar, Crossref
- Samuel R, Stephanie S, Alan RS. Chronic Intermittent Hypoxia and Pulmonary Hypertension. Sleep Med Clin. 2019;14(3):363-371.
Indexed at, Google Scholar, Crossref
- Zhaoxian L, Xiangyu D, Ruonan G. Oxygen Therapy in Patients With Obstructive Sleep Apnea-Related Pulmonary Hypertension: Where Are We Now?. Front Cardiovasc Med. 2022;9:956611.
Indexed at, Google Scholar, Crossref
- Feras A, Waleed HF, Alaa A. Pulmonary Hypertension Secondary to Obstructive Sleep Apnea: A Comprehensive Review. Pulm Ther. 2021;7(2):297-310.