What are the best practices for managing Obstructive Sleep Apnea (OSA) with central apneas?

Managing OSA with Central Apneas

For patients with obstructive sleep apnea (OSA) who develop central apneas, adaptive servo-ventilation (ASV) is the most effective treatment modality, normalizing both obstructive and central respiratory events while improving sleep quality and patient-reported outcomes. 1, 2, 3

Initial Assessment and Diagnosis

When central apneas emerge in OSA patients, determine the clinical context:

• Complex Sleep Apnea Syndrome (CompSAS): Central apneas that emerge or predominate when CPAP is applied to treat OSA, affecting approximately 63% of patients requiring advanced ventilation 4
• Coexisting CSA/OSA: Central apneas present at baseline alongside obstructive events 1, 2
• Treatment-emergent central apneas: Central events appearing during CPAP titration that maintain elevated AHI despite resolution of obstructive events 4

Establish severity through polysomnography showing the apnea-hypopnea index (AHI) and the proportion of central versus obstructive events 5, 4

Treatment Algorithm

First-Line Approach: Trial of Standard PAP

Attempt CPAP optimization first, as some central apneas may resolve with adequate treatment of the obstructive component 5, 4:

• Titrate CPAP to eliminate obstructive events using attended polysomnography 5
• If central AHI remains elevated (>5 events/hour) or total AHI >10 events/hour despite adequate CPAP pressure, proceed to advanced ventilation 4

Critical pitfall: Standard CPAP worsens central apneas in CompSAS, and bilevel PAP in spontaneous mode (without backup rate) can dramatically worsen the AHI to 75 events/hour versus baseline 4

Second-Line: Adaptive Servo-Ventilation

ASV should be initiated when CPAP fails to control central apneas or when CompSAS is identified 1, 2, 4:

• ASV combines automatic CPAP adjustment for obstructive events with anticyclic pressure support that suppresses central apneas and Cheyne-Stokes breathing 1, 6
• The device measures minute ventilation or airflow continuously, calculates a target ventilation, and adjusts inspiratory pressure support on a breath-by-breath basis 6
• ASV provides a backup respiratory rate to prevent central apneas 6, 4

Efficacy data: ASV reduces total AHI from 43.8/hour to 2.1/hour, obstructive AHI from 12.8/hour to 0.3/hour, and central AHI from 31.0/hour to 1.7/hour 1. In a large series, 64% of patients achieved AHI <10 events/hour with ASV versus persistent elevation with CPAP 4

Alternative: Bilevel PAP with Backup Rate

If ASV is unavailable or not tolerated, bilevel PAP with a backup respiratory rate can be considered 5, 4:

• This modality improved AHI to 15 events/hour in one series, though less effectively than ASV (5 events/hour) 4
• Noninvasive positive pressure ventilation (NPPV) titration should follow AASM guidelines for chronic alveolar hypoventilation when this approach is used 5

Critical contraindication: Never use bilevel PAP in spontaneous mode (without backup rate) for central apneas, as this can worsen respiratory events 4

Special Populations and Contraindications

Heart Failure Patients

Exercise extreme caution in patients with systolic heart failure and reduced ejection fraction:

• Absolute contraindication: Do not use ASV in patients with left ventricular ejection fraction (LVEF) <30% and predominant central sleep apnea, based on the SERVE-HF trial showing increased mortality 2
• Relative contraindication: In patients with LVEF 30-45%, ASV initiation should only occur in expert sleep centers after optimal heart failure treatment and failed CPAP trial 2
• Safe populations: Current ASV devices show no negative cardiovascular outcomes in heart failure with preserved ejection fraction (HFpEF) or in patients without heart failure 2

Patients Without Heart Failure

ASV is safe and effective for CompSAS and CSA in patients without systolic heart failure 2, 3:

• Improvements in quality of life (FOSQ score increase of +0.8) and sleepiness (ESS score decrease of -2.0) occur after 12 months 3
• Symptomatic patients (baseline FOSQ <17.9 or ESS >10) show the greatest benefit, with FOSQ improvement of +1.69 points 3

Monitoring and Follow-Up

After ASV initiation:

• Perform follow-up polysomnography with the device in place after final adjustments to confirm adequate control of both obstructive and central events 5
• Monitor for resolution of clinical symptoms including witnessed apneas, nocturnal dyspnea, morning headaches, and excessive daytime sleepiness 5
• Assess device adherence through telemonitoring, as adherence is critical for cardiovascular risk reduction 7
• Evaluate improvements in sleep architecture, particularly REM sleep percentage, which increases from 10-12% to 18% with effective ASV 4

Adjunctive Therapies

Regardless of ventilation mode selected, address modifiable risk factors:

• Weight loss: Strongly counsel all overweight/obese patients on weight loss as first-line therapy, as this improves AHI independent of PAP therapy 8, 7
• Positional therapy: Consider for patients with positional OSA component, though compliance is poor long-term 7
• Optimize underlying conditions: Treat heart failure, hypertension, and atrial fibrillation aggressively, as these represent high-risk phenotypes requiring particularly aggressive OSA management 8