From the Guidelines
Central sleep apnea evaluation should prioritize a comprehensive approach, including a detailed sleep history and physical examination, followed by an overnight polysomnography (sleep study) as the primary diagnostic test. This approach is crucial in identifying the underlying cause of central sleep apnea, which can be closely linked to heart failure, particularly in patients with HFrEF, as noted in the 2016 ESC guidelines for the diagnosis and treatment of acute and chronic heart failure 1.
The evaluation process should consider the following key points:
- A detailed sleep history, including asking a partner, is essential in assessing sleep disturbances and sleep-disordered breathing patterns.
- Overnight polysomnography can distinguish between central sleep apnea (CSA) and obstructive sleep apnea (OSA), which is vital for guiding treatment decisions.
- Additional testing, such as arterial blood gas analysis, echocardiography, and brain imaging, may be necessary to assess carbon dioxide levels, heart function, and potential neurological causes.
- Screening for risk factors, including heart failure, stroke, opioid use, and high altitude exposure, is critical in identifying potential underlying causes of central sleep apnea.
- Assessment of daytime sleepiness using tools like the Epworth Sleepiness Scale can provide valuable insights into the impact of central sleep apnea on the patient's quality of life.
Treatment should target the underlying cause, and given the recent findings from the SERVE-HF trial, adaptive servo-ventilation (ASV) is not recommended in patients with HFrEF and predominantly CSA due to its association with increased mortality 1. Instead, positive airway pressure therapy (CPAP or BiPAP), supplemental oxygen, medication adjustments, or treatment of heart failure may be considered, depending on the specific cause and severity of central sleep apnea.
From the Research
Central Sleep Apnea Evaluation
Central sleep apnea (CSA) is a condition characterized by pauses in breathing during sleep due to a lack of effort to breathe. The evaluation of CSA involves several steps, including:
- Identifying the underlying cause of CSA, such as heart failure, stroke, or opioid use 2
- Assessing the severity of CSA using polysomnography (PSG) or other diagnostic tools 3
- Evaluating the patient's medical history, including any underlying medical conditions that may be contributing to CSA 2
Treatment Options
Treatment options for CSA depend on the underlying cause and severity of the condition. Some common treatment options include:
- Positive airway pressure (PAP) therapy, such as continuous positive airway pressure (CPAP) or adaptive servo-ventilation (ASV) 3, 2
- Acetazolamide, a medication that can help reduce the frequency of central apneas 4, 5, 6
- Oxygen therapy, which can help improve oxygen saturation during sleep 3
- Pharmacologic therapy, such as theophylline or zolpidem, which can help improve sleep quality and reduce the frequency of central apneas 3
Specific Treatment Recommendations
Specific treatment recommendations for CSA depend on the underlying cause and severity of the condition. For example:
- For primary CSA, a trial of PAP, acetazolamide, or zolpidem may be recommended 3
- For CSA due to Cheyne-Stokes breathing pattern in congestive heart failure, PAP devices such as CPAP or ASV may be recommended, as well as oxygen therapy 3
- For CSA due to high-altitude periodic breathing, descent from altitude or supplemental oxygen may be recommended, as well as acetazolamide if necessary 3
- For CSA due to drug or substance use, a trial of CPAP or ASV may be recommended, as well as treatment with bilevel positive airway pressure-spontaneous timed mode (BPAP-ST) if necessary 3
Acetazolamide as a Treatment Option
Acetazolamide has been shown to be effective in reducing the frequency of central apneas in patients with CSA. Studies have demonstrated that acetazolamide can: