Diagnosis and management of central sleep apnea syndrome

ABSTRACT

Introduction: Central sleep apnea (CSA) syndrome has gained a considerable interest in the sleep field within the last 10 years. It is overrepresented in particular subpopulations such as patients with stroke or heart failure. Early detection and diagnosis, as well as appropriate treatment of central breathing disturbances during sleep remain challenging.

Areas covered: Based on a systematic review of CSA in adults the clinical evidence and polysomnographic patterns useful for discerning central from obstructive events are discussed. Current therapeutic indications of CSA and perspectives are presented, according to the type of respiratory disturbances during sleep, alterations in blood gases and ventilatory control.

Expert opinion: The precise identification of central events during polysomnographic recording is mandatory. Therapeutic choices for CSA depend on the typology of respiratory disturbances observed by polysomnography, changes in blood gases and ventilatory control. In CSA with normocapnia and ventilatory instability, adaptive servo-ventilation is recommended. In CSA with hypercapnia and/or rapid-eye movement sleep hypoventilation, non-invasive ventilation is required. Further studies are required as strong evidence is lacking regarding the long-term consequences of CSA and the long-term impact of current treatment strategies.

Trial registration: ClinicalTrials.gov identifier: NCT02835638.

Trial registration: ClinicalTrials.gov identifier: NCT03032029.

Trial registration: ClinicalTrials.gov identifier: NCT03745898.

KEYWORDS:

• Central sleep apnea
• intermittent hypoxia
• heart failure
• stroke
• polysomnography
• adaptive servo-ventilation
• ventilatory control
• prognosis

Article highlights

• Central sleep apnea (CSA) syndrome encompasses a group of sleep-related breathing disorders often associated with various other medical conditions.

• Robust evidence is currently lacking regarding the long-term consequences of CSA and data are relatively scarce on the long-term impact of current treatment strategies. This should be taken into consideration when evaluating the need for early assessment and appropriate treatment.

• Differentiating central versus obstructive hypopneas during polysomnographic scoring is strongly recommended in order to properly diagnose CSA.

• The distinction between hypercapnic vs. eucapnic/hypocapnic (non-hypercapnic) CSA is valuable both for identification of the underlying disease/context and deciding on the appropriate ventilatory support.

• Congestive heart failure (CHF) is the most common condition associated with CSA. Cheyne-Stokes breathing (CSB) is a stereotypical breathing pattern of CSA in CHF, characterized by repetitive, cyclic, waxing and waning changes in tidal volume interspersed by central apnea with a prolonged cycle time.

• In CSA related to heart failure with reduced ejection fraction, Adaptive Servo-Ventilation (ASV) is associated with an increase in all-cause and cardiovascular mortality and is currently contraindicated in this specific population (SERVE-HF study). ASV remains indicated in CHF with preserved ejection fraction.

• Treatment-emergent CSA patients were at higher risk of therapy termination versus those who did not develop CSA and should be shifted from CPAP to ASV.

• Therapeutic choices for CSA are dependent on the type of respiratory disturbances during sleep documented by PSG and on the nature of modifications in blood gases and ventilatory control. In CSA with normocapnia and ventilatory instability, ASV is the appropriate ventilatory support. In hypercapnia and/or REM sleep hypoventilation, non-invasive ventilation is required.

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Acknowledgments

We thank Alison Foote, PhD (Grenoble Alpes University Hospital) for critical reading and substantial language editing of the revised manuscript.

Reviewers disclosure

Professor Jean-Louis Pepin declares grants and research funds from Air Liquide Foundation, Agiradom, AstraZeneca, Fisher and Paykel, Mutualia, Philips, Resmed and Vitalaire and receiving fees from Agiradom, AstraZeneca, Boehringer Ingelheim, Jazz pharmaceutical, Night Balance, Philips, Resmed and Sefam. Professor Renaud Tamisier declares receiving grants and research funds from Resmed, Vitalaire and Philips and travel grants from Agiradom. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Declaration of interest

No potential conflict of interest was reported by the authors.

Additional information

Funding

Funding from French National Research Agency (Agence Nationale de la Recherche) in the framework of the ‘Investissements d’avenir’ program (ANR-15-IDEX-02).