CPAP for Central Sleep Apnea: Clinical Recommendation
CPAP can be used for central sleep apnea and is conditionally recommended as a treatment option, though it is not the optimal first-line therapy for most CSA patients. 1
Primary Treatment Recommendation
The American Academy of Sleep Medicine suggests using CPAP over no CPAP in adults with CSA across multiple etiologies, including primary CSA, CSA due to heart failure, medication-induced CSA, treatment-emergent CSA, and CSA due to medical conditions. 1 However, this is a conditional recommendation based on low certainty evidence, meaning the benefits may not apply uniformly to all patients. 1
Critical Clinical Context: Heart Failure Patients
In patients with heart failure and reduced ejection fraction (HFrEF), CPAP is acceptable but adaptive servo-ventilation should be avoided due to demonstrated harm. 2 The ACC/AHA/HFSA guidelines explicitly state that adaptive servo-ventilation causes harm in NYHA class II-IV HFrEF patients with central sleep apnea, with increased all-cause and cardiovascular mortality. 2
Treatment Algorithm for Central Sleep Apnea
First-Line Considerations:
- Optimize underlying conditions first - Address heart failure management, discontinue or reduce opioids if possible, and treat other contributing medical conditions before initiating positive airway pressure therapy. 1
- CPAP trial - Start with CPAP as it has demonstrated efficacy in reducing central apneas in some patients, with historical case reports showing dramatic improvement (reduction from 281 to 32 central apneas per night at 7.5 cm H₂O). 3
When CPAP Fails or Is Suboptimal:
BiPAP with backup rate - The AASM suggests using BiPAP with a backup rate (not without backup rate) for primary CSA, medication-induced CSA, treatment-emergent CSA, and CSA due to medical conditions. 1 This is critical because BiPAP without a backup rate can worsen central apneas, with studies showing worsening of CSR and non-CSR central apneas in 24% and 23% of patients respectively. 4
Adaptive servo-ventilation (ASV) - ASV is conditionally recommended and appears highly effective (reducing AHI to mean of 5 events/hour), but requires careful patient selection and shared decision-making. 5, 1 ASV must be avoided in HFrEF patients and should only be used in experienced centers with close monitoring. 1
Alternative Therapies:
- Low-flow oxygen - Conditionally recommended for CSA due to heart failure and high-altitude CSA. 1
- Oral acetazolamide - Conditionally recommended across multiple CSA etiologies. 1
Critical Pitfalls to Avoid
Do not use BiPAP without a backup rate - This can significantly worsen central apneas, particularly in patients with baseline Cheyne-Stokes respiration or periodic breathing (worsening in 62% and 48% respectively). 4 The AASM specifically suggests against BiPAP without backup rate. 1
Do not use ASV in HFrEF - This is a Class III: Harm recommendation with strong evidence of increased mortality. 2
Higher pressure differentials worsen outcomes - In BiPAP therapy, higher pressure differences between inspiratory and expiratory pressures worsened central events in 28% of patients. 4
Practical Implementation
When initiating CPAP for CSA:
- Start with standard CPAP pressures (typically 4-7.5 cm H₂O initially). 3
- Monitor for persistence or worsening of central events, which should prompt re-evaluation and consideration of alternative treatments. 1
- Prioritize patient-reported outcomes and quality of life improvement over simply eliminating respiratory events. 1
- If CPAP is ineffective, escalate to BiPAP with backup rate or consider ASV (if not contraindicated), rather than BiPAP without backup rate. 1, 4
Evidence Quality Considerations
The evidence supporting CPAP for CSA is of low certainty, with most recommendations being conditional rather than strong. 1 Real-world data shows variable response rates: in one study of 64 CSA patients, 42.2% responded to CPAP, 20.3% to CPAP plus oxygen, and 28.1% to BiPAP. 6 CPAP showed particularly appropriate results in patients with congestive heart failure and ischemic heart disease. 6