| How it works |
Blows slight air through a mask into the airway to maintain patency |
Alters upper airway patency. Two types – mandibular repositioning or tongue retaining devices |
Various surgical procedures either reducing or by-passing pharyngeal resistance |
| Standardisation |
Yes |
No – over 60 types of devices exist with non-standardised designs |
No – procedures vary in complexity. Uvulopatatopharyngoplasty (UPPP) & laser-assisted UPPP are most common. Tracheostomy is last resort. |
| Effect on apnea |
Normalises respiratory disturbance index (RDI) to less than 5 per hour |
Average success rate for normalization is 42%. Effect on severe OSA unpredictable |
50% chance of 50% reduction in RDI. OSA may return with time or weight gain. Exception is tracheostomy which normalises RDI. |
| Effect on daytime sleepiness |
Significant improvements in subjective and objective sleepiness |
Evidence support improvement in subjective sleepiness |
Variable |
| Effect on other conditions |
Improves 5-year survival rate, reduces incidence of stroke, myocardial infarction and recurrence risk of atrial fibrillation; improves blood pressure, glycemic control, nocturnal gastro-oesophageal reflux and cognitive function. |
Improvement in blood pressure. No evidence of other beneficial outcome. |
No evidence of other beneficial outcomes |
| Side effects |
Dry mouth, rhinitis, nasal bridge sores. All side effects are reversible and most can be overcome with heated humidification and the right mask. |
Temporomandibular joint pain, maofascial pain, tooth/gum pain, excessive salivation, dry mouth, occlusal changes. Most side effects reversible. |
Invasive procedure entailing all usual surgical risks. Surgery may irreversibly prevent subsequent use of CPAP. Tracheostormy is aesthetically undesirable and is associated with complications and significant emotional difficulties. |
