Types of sleep disordered breathing (SDB)
There are three main types of sleep-disordered breathing which are manifested in sleep apnoea. Discovering the specific differences between them can help you recognise how best to treat your patients.
- Obstructive sleep apnoea (OSA)
- Central sleep apnoea (CSA)
- Complex sleep apnoea
OSA is a common disorder characterised by repetitive upper airway collapse during sleep resulting in apnoeas (cessation of airflow) and hypoapnoeas (reduced airflow)1.
The primary indications of upper airway obstruction are:
- lack of muscle tone during sleep
- excess tissue in the upper airway
- the structure of the upper airway and jaw
OSA determined by polysomnography is highly prevalent, affecting 25% of men and 10% of women in the United States although most are asymptomatic.2
Central sleep apnoea (CSA)
CSA is clinically defined by a lack of drive to breathe during sleep, resulting in repetitive periods of insufficient ventilation leading to compromised gas exchange, in contrast to OSA where there is an ongoing respiratory effort.3 These nocturnal breathing disturbances can lead to various comorbidities and can increase the risk of cardiovascular events.3 There are several known variations of CSA, including high altitude-induced periodic breathing, idiopathic CSA, narcotic-induced CSA, and Cheyne-Stokes respiration (CSR). While unstable ventilatory control during sleep is an indication of CSA, the pathophysiology and the prevalence of the various forms can vary greatly.
Patients with CSA don't often snore, so the condition sometimes goes unnoticed.
Complex sleep apnoea
Complex sleep apnoea (CompSA) can be clinically defined as a combination of obstructive sleep apnoea with central sleep apnoea or Cheyne-Stokes breathing pattern.4 Patients who have CompSA present with both a reduced upper airway tone, resulting in an obstruction during sleep, and unstable ventilatory control, resulting in a cessation of respiratory effort leading to a central apnoea.4