What are the best practices for treating patients with coexisting obstructive sleep apnea (OSA) and central apneas at baseline?

Treatment of Coexisting OSA with Central Apneas at Baseline

For patients with coexisting obstructive sleep apnea (OSA) and central apneas at baseline, initiate treatment with attended polysomnography-guided NPPV titration (bilevel PAP or adaptive servo-ventilation) rather than CPAP alone, as CPAP frequently fails to adequately suppress central events in this mixed population. 1

Initial Diagnostic Approach

When baseline polysomnography reveals both obstructive and central respiratory events:

• Quantify the proportion of central versus obstructive events to guide therapy selection—patients with >50% central events or central apnea index exceeding obstructive apnea index require specialized ventilatory support beyond standard CPAP 1
• Assess for underlying cardiac disease, particularly heart failure, as this significantly influences treatment choice and prognosis 1, 2
• Evaluate for opioid use, as opioid-induced central apneas may respond to ASV 3

Treatment Algorithm

Step 1: Attended In-Laboratory Titration (Standard Recommendation)

Attended NPPV titration with polysomnography is the standard method to determine effective pressure settings when OSA coexists with central apneas 1. Home auto-titration is inappropriate for this complex population 1.

Step 2: Initial Pressure Mode Selection

Start with bilevel PAP (BPAP) with backup rate as the first-line approach:

• Begin with IPAP 8 cm H₂O and EPAP 4 cm H₂O (minimum starting pressures) 1
• Minimum pressure support of 4 cm H₂O (IPAP minus EPAP) 1
• First eliminate obstructive events by increasing IPAP and EPAP per standard OSA titration protocols 1
• Then address central events and hypoventilation by adjusting pressure support to achieve tidal volumes of 6-8 mL/kg ideal body weight 1
• Increase pressure support by 1-2 cm H₂O increments every 5 minutes if tidal volume remains below target 1
• Maximum IPAP should not exceed 30 cm H₂O in adults (20 cm H₂O in children <12 years) 1

Step 3: Consider Adaptive Servo-Ventilation (ASV) for Refractory Cases

If BPAP with backup rate fails to adequately suppress central events (residual AHI >10), transition to ASV 4, 5:

• ASV is significantly more effective than BPAP in reducing central apnea-hypopnea index (mean reduction to 0.8-6.1 events/hour vs 15 events/hour with BPAP) 4, 5, 2
• ASV dynamically adjusts inspiratory pressure support based on 90% of recent minute ventilation, preventing both under- and over-ventilation 1
• ASV normalizes both obstructive and central events in mixed populations more effectively than any other modality 6, 4, 5

Critical Contraindication

Do NOT use ASV in patients with heart failure and reduced ejection fraction (LVEF ≤45%) unless specifically indicated by updated guidelines, as the 2016 AASM updated recommendations addressed safety concerns in this population 1. For heart failure patients with coexisting OSA and central apneas, BPAP with backup rate remains the safer option 2.

Monitoring Parameters During Titration

Track these specific metrics during attended titration 1:

• Tidal volume (target 6-8 mL/kg ideal body weight)
• Respiratory rate (should decrease with adequate support)
• Oxygen saturation via pulse oximetry
• PCO₂ via transcutaneous or end-tidal monitoring
• Elimination of obstructive apneas, hypopneas, RERAs, and snoring
• Suppression of central apneas (goal: central AHI <5 events/hour)
• Reduction in respiratory-related arousals

Follow-Up and Adherence Support

• Provide educational interventions at PAP initiation (strong recommendation for all PAP therapy) 1
• Implement behavioral and troubleshooting interventions during the initial treatment period 1
• Use objective monitoring of efficacy and adherence data to ensure adequate treatment 1
• Schedule early follow-up (within 2-4 weeks) to address mask fit issues, pressure intolerance, or persistent symptoms 1

Common Pitfalls to Avoid

• Never use standard CPAP or auto-CPAP alone in patients with significant baseline central apneas—this frequently worsens central events or fails to suppress them adequately 4, 5
• Do not attempt home auto-titration in this population, as it cannot differentiate or appropriately treat mixed events 1
• Avoid under-titrating pressure support—inadequate support leaves residual hypoventilation and central events 1
• Do not ignore underlying cardiac disease—heart failure with reduced ejection fraction changes the risk-benefit profile of ASV 1, 2