From the Guidelines
The most likely cause of central sleep apnea is heart failure, particularly heart failure with reduced ejection fraction (HFrEF), as it is closely linked to central sleep apnea (CSA) and is the most common cause of CSA. Central sleep apnea occurs when the brain temporarily fails to send proper signals to the breathing muscles, unlike obstructive sleep apnea which involves physical blockage of the airway. According to the 2016 ESC guidelines for the diagnosis and treatment of acute and chronic heart failure 1, CSA is the most common form of sleep-disordered breathing in HFrEF, and HFrEF is the most common cause of CSA. Other causes of central sleep apnea include stroke, brain tumors, brainstem lesions, and certain medications like opioids, as discussed in the British Journal of Pharmacology study on the impact of concomitant medications on obstructive sleep apnea 1. High altitude exposure can also trigger central sleep apnea due to changes in oxygen levels. Medical conditions that affect the brainstem, such as encephalitis or Parkinson's disease, may contribute as well. Treatment depends on identifying and addressing the underlying cause, which might include optimizing heart failure management, adjusting medications, using adaptive servo-ventilation devices, or supplemental oxygen therapy. For opioid-induced central sleep apnea, dose reduction may be necessary, as opioids can cause relaxation of the tongue and upper airway muscles, leading to airway obstruction and exacerbating obstructive sleep apnea 1.
Some key points to consider in the diagnosis and treatment of central sleep apnea include:
- Screening for sleep apnea is an important part of the holistic care of patients with heart failure, as it can have a significant impact on morbidity and mortality 1
- The apnea/hypopnea index (AHI) can be used to diagnose and monitor sleep apnea, with an AHI of above 30 per hour indicating severe sleep apnea 1
- Treatment options for central sleep apnea include continuous positive airway pressure (CPAP), bi-level positive airway pressure (BiPAP), and adaptive servo-ventilation (ASV), although the use of ASV in patients with HFrEF and predominantly CSA is not recommended due to the increased risk of mortality 1
- Identifying and addressing the underlying cause of central sleep apnea is crucial in developing an effective treatment plan, and may involve optimizing heart failure management, adjusting medications, or using supplemental oxygen therapy.
From the Research
Central Sleep Apnea Causes
- The most likely cause of central sleep apnea is associated with chronic opioid use 2, 3, 4.
- Studies have shown that chronic opioid use can lead to the development of central sleep apnea, with a prevalence of 24% in patients taking chronic opioids 3.
- The mechanisms behind opioid-induced central sleep apnea are not fully understood, but it is thought to be related to the effects of opioids on the brain's respiratory centers 3.
Risk Factors
- High morphine equivalent daily dose (MEDD) is a significant risk factor for the severity of central sleep apnea, with an MEDD of >200 mg being a threshold of particular concern 3.
- Concurrent use of benzodiazepines or hypnotics may also contribute to the severity of central sleep apnea 3.
- Low or normal body mass index is inversely related to the severity of sleep-disordered breathing, including central sleep apnea 3.
Treatment Options
- Adaptive servoventilation is considered an effective treatment option for central sleep apnea, particularly in patients with chronic opioid use 2, 5, 4.
- Continuous positive airway pressure (CPAP) may be ineffective in eliminating central sleep apnea and may even increase its severity in some cases 2, 3, 4.
- Bilevel positive airway pressure ventilation and supplemental oxygen therapy may also be used to treat central sleep apnea, but their effectiveness is not well established 5, 3.