Which diagnostic tests are recommended for confirming a diagnosis of central sleep apnea in primary care settings?

In primary care settings, confirming a diagnosis of central sleep apnea (CSA) requires referral for specialist sleep assessment, as the initial diagnostic tools commonly used for obstructive sleep apnea (OSA) are not sufficient to definitively diagnose CSA. The recommended diagnostic approach begins with clinical assessment and screening tools such as the Epworth Sleepiness Scale and STOP-Bang questionnaire to identify patients with suspected sleep-disordered breathing, but these do not differentiate CSA from OSA NICE NG202.

For diagnostic confirmation, home respiratory polygraphy is generally offered for suspected obstructive sleep apnea; however, it primarily detects obstructive events and may not reliably distinguish central apneas NICE NG202. If home respiratory polygraphy or oximetry results are inconclusive or symptoms persist, referral for polysomnography (PSG) in a specialist sleep laboratory is advised. PSG is the gold standard diagnostic test that records multiple physiological parameters during sleep, including airflow, respiratory effort, oxygen saturation, and brain activity, enabling differentiation between central and obstructive apneas NICE NG202,NICE CKS.

In cases where central sleep apnea is suspected—such as in patients with heart failure, neurological disorders, or opioid use—PSG is essential to confirm the diagnosis and guide management NICE NG202. Additionally, transcutaneous carbon dioxide monitoring during sleep may be considered to provide further information on hypoventilation and central respiratory control, especially in complex cases or overlap syndromes NICE NG202.

Overall, primary care clinicians should focus on identifying patients at risk and promptly referring them for specialist assessment and polysomnography to confirm central sleep apnea, as no standalone diagnostic test in primary care can definitively diagnose CSA NICE NG202. Recent population-based studies highlight the importance of comprehensive sleep studies for accurate diagnosis and outcome assessment of primary central sleep apnea Kouri et al. 2020, reinforcing the guideline recommendations for specialist evaluation.