From the Guidelines
Sleep-related hypoventilation requires immediate attention and treatment to prevent severe complications, including pulmonary hypertension, right heart failure, and increased mortality, and the primary recommendation is to address the underlying cause, with positive airway pressure therapy being the mainstay of treatment, as stated in the 2019 American Thoracic Society clinical practice guideline 1.
Overview of Sleep-Related Hypoventilation
Sleep-related hypoventilation is a breathing disorder characterized by decreased ventilation during sleep, leading to elevated carbon dioxide levels in the blood. The condition can be caused by various factors, including obesity, neuromuscular disorders, chest wall abnormalities, or COPD.
Treatment Approaches
Treatment typically involves addressing the underlying cause, and for obesity-related hypoventilation, weight loss is the primary recommendation, with a goal of 5-10% reduction in body weight through diet and exercise.
- Positive airway pressure therapy is the mainstay of treatment, with CPAP (starting at 8-12 cmH2O) used for concurrent obstructive sleep apnea, or BiPAP (inspiratory pressure 12-20 cmH2O, expiratory pressure 4-6 cmH2O) for more severe cases, as recommended by the American Academy of Sleep Medicine 1.
- Supplemental oxygen may be added if hypoxemia persists.
- For patients with neuromuscular disorders, non-invasive ventilation is essential, typically BiPAP with backup rate.
- Medications like respiratory stimulants (acetazolamide 125-250mg twice daily) may be considered in select cases.
Monitoring and Follow-up
Regular follow-up with sleep studies and arterial blood gas measurements is necessary to monitor treatment effectiveness, as stated in the 2010 Journal of Clinical Sleep Medicine guideline 1. This condition requires treatment because chronic hypoventilation leads to hypercapnia, respiratory acidosis, and can cause pulmonary hypertension, right heart failure, and increased mortality if left untreated.
Key Considerations
- Attended NPPV titration with polysomnography is the standard method to determine an effective level of NPPV support when the treatment goal(s) is (are) to reduce sleep fragmentation and improve sleep quality, decrease the work of breathing and provide respiratory muscle rest, normalize or improve gas exchange, and relieve or improve nocturnal symptoms in patients with nocturnal hypoventilation, as recommended by the NPPV titration task force 1.
- The goals of NPPV titration and treatment should be individualized, and different levels of NPPV support may be needed depending on the specific goals in an individual patient, as stated in the 2010 Journal of Clinical Sleep Medicine guideline 1.
From the Research
Definition and Causes of Sleep-Related Hypoventilation
- Sleep-related hypoventilation is a condition characterized by a reduction of the minute ventilation with an increase of daytime hypercapnia, which manifests firstly during sleep 2.
- It can be caused by various factors, including congenital disorders, neurological diseases, thoraco-skeletal or muscular diseases, and obesity hypoventilation syndrome.
Treatment of Sleep-Related Hypoventilation
- Non-invasive ventilation (NIV) is a common treatment for sleep-related hypoventilation, which can help improve ventilation, reduce hypercapnia, and increase oxygenation 2, 3, 4.
- The adaptation of NIV treatment should be performed under close medical supervision, and pressure support algorithms have become most frequently used 2.
- Bi-level positive airway pressure (BiPAP) and continuous positive airways pressure (CPAP) are two common modes of NIV, which have been shown to be effective in treating sleep-related hypoventilation 3, 5.
Comparison of Different NIV Modes
- A study compared the efficacy of auto-trilevel PAP and BiPAP ventilation in patients with concurrent obesity hypoventilation syndrome and obstructive sleep apnea syndrome, and found that auto-trilevel PAP ventilation was more effective in correcting hypercapnia and improving sleep quality 5.
- Another study compared Bi-level PAP and CPAP for initial treatment of obesity hypoventilation syndrome, and found that both modes resulted in similar improvements in ventilatory failure, health-related quality of life, and adherence 3.
Barriers to NIV Access and Proposed Solutions
- The existing coverage criteria for home NIV do not recognize the diversity of hypoventilation syndromes and advances in technologies, which can create barriers to access 6.
- A technical expert panel proposed several key suggestions to improve access to NIV, including acceptance of surrogate noninvasive end-tidal and transcutaneous Pco2 and venous blood gases, and removal of spirometry as a requirement 6.