Treatment Options - Continuous Positive Airway Pressure (CPAP)
Treatment options depend on the severity of OSA.
The level of evidence for treatment options on this page is based on GRADE ratings.1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31
Treatment options should be considered, depending on the apnoea-hypopnoea index (AHI), body mass index (BMI), symptoms (See Assessment – History), comorbidities (See Comorbidities & Complications), possible pathophysiological background and preference of the patient (CPAP clinical pathway - HealthPathways).
The continuous positive airway pressure (CPAP) device delivers pressurised air to a patient’s airway via a pump and mask which is worn during sleep to create a positive pharyngeal transmural pressure so that the intraluminal pressure exceeds the surrounding pressure and prevents collapse (i.e. apnoeas, hypopnoeas), also through increased end-expiratory lung volume. CPAP has been the standard treatment for OSA since 1981. CPAP machines vary in prices from ~$750 to ~$2,000 with Australian Health Fund Rebates of ~$500-$1,000.
There are a variety of CPAP interfaces/masks available, including:
- Nasal mask which covers the nose but not mouth
- Full face (oronasal) mask which covers the nose and mouth, allowing mouth breathing during therapy (eg patients with nasal obstruction
- Nasal pillows which consist of prongs that insert directly into the nostrils, so no components are pressing on the nasal bridge
Table. The most common modes of positive airway pressure
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It has been reported that APAP 32, 33 and BiPAP 34 are comparable to CPAP for the management of OSA. However, BiPAP is less commonly used and tends to be reserved for patients requiring very high CPAP pressures, who have obesity-hypoventilation syndrome, neuromuscular disorders or other conditions causing type 2 respiratory failure.
With CPAP titration, an in-laboratory CPAP sleep study is used to determine the optimal pressure required to control the obstructive events. Whilst the patient is undergoing PSG monitoring, CPAP is commenced at a low pressure and the pressure level is progressively increased over the course of the night to determine the lowest pressure that successfully abolishes the obstructive respiratory events, restores normal oxygen saturations, and improves sleep quality. A fixed pressure CPAP device can then be set to the appropriate setting and trialled at home by the patient. The optimal pressure will generally be between 5 and 20 centimetre of water (cmH2O).
Alternatively, APAP devices can be trialled at home to determine the optimal pressure. The machine has a built-in algorithm to automatically adjust the pressure according to detected obstructive events, within a set pressure range (e.g. minimum 5, maximum 20 cmH2O).
APAP devices can be either set in a fixed pressure mode or run in an automatically titrating mode for long term therapy. However, these devices may be more expensive than standard fixed pressure machines. Furthermore, there is no evidence to suggest that automatically titrating CPAP is superior to fixed pressure CPAP when used in the long term.
A humidification system is available built into or can be added on to CPAP or APAP devices to moisturise the air and reduce nasal discomfort and dryness. Nasal discomfort can also be temporarily managed by using non-medicated nasal moisturizing products available over the counter.
Efficacy of CPAP
The American Academy of Sleep Medicine performed a meta-analysis and GRADE assessment on the effectiveness of CPAP which was published in the Journal of Clinical Sleep Medicine in 2019 and concluded that CPAP compared to no treatment results in a clinically significant reduction in disease severity, sleepiness, blood pressure, and motor vehicle accidents, and improvement in sleep-related quality of life in adults with OSA. 23
An improvement in sleepiness symptoms, including a reduction in related traffic accidents 35 can be achieved following therapy with continuous positive airway pressure (CPAP).36, 37
Table. CPAP vs. control
| Apnoea-hypopnoea index (AHI)
High GRADE | CPAP, when compared to control, reduces AHI (associated with higher baseline AHI) 23,26,24 |
The meta-analyses of Patil 23, Sharples 26 and Qaseem 24 reported a significant improvement in AHI following treatment with CPAP when compared to control / sham CPAP.
Patil 23 reported, based on 11 included RCTs, a clinically significant pooled reduction in AHI of −29 events per hour (95% CI -37, -20) an AHI reduction of 86% (mean pre treatment AHI was 32.7 ± 12.6 events per hour and posttreatment AHI was 4.1 ± 5.6 events per hour).
Sharples 26 reported, based on 25 included studies, a pooled reduction in AHI of -25.4 events per hour (95% CI -30.67, -20.07) of CPAP compared to control, with a greater effect in patients with a higher baseline AHI; a decrease of -39.8 vs. -13.7 in patients with a AHI baseline of > 30 compared to 5 – 14.
Qaseem 24 reported, based on 7 included studies, a pooled reduction in AHI of -19.9 events per hour (95% CI -26.1, -13.7; baseline AHI 10 – 65 ) of CPAP compared to control, and, based on 8 included studies, a pooled reduction in AHI of -46.6 events per hour (95% CI -57.0, -35.8; baseline AHI 22 – 68 ) of compared to sham CPAP, with a greater effect in patients with a higher baseline AHI in both analyses.
Clinically relevant decrease in AHI is ≥15 events per hour. 23
| Sleepiness (Epworth sleepiness scale (ESS))
High GRADE |
The meta-analyses of Patil 23; Campos-Rodriguez 3; Sharples 26; Bratton 38 Qaseem 24 reported a significant improvement in sleepiness, as measured with the Epworth Sleepiness Scale (ESS), following treatment with CPAP compared to control / sham CPAP.
Patil 23 reported, based on 38 included RCTs, a clinically significant pooled reduction in self-reported sleepiness of -2.4 points ESS (95% CI -2.8, -1.9) for CPAP compared to control.
Campos-Rodriquez 3 reported a pooled reduction in sleepiness of -2.92 points ESS (95% CI -3.73, -2.11) for CPAP compared to control.
Sharples 26 reported, based on 38 included studies, a pooled reduction in sleepiness of -2.2 points ESS (95% 95% CI -2.8 to -1.7) for CPAP compared to control, with a greater effect in patients with a higher baseline ESS score; a decrease of -2.64 (95% CI -3.44, -1.84) vs. -1.23 (95% CI -2.19, -0.27) in patients with an AHI baseline of > 30 compared to 5 – 14.
Bratton 2 reported a pooled reduction in sleepiness of -2.5 points ESS (95% CI -2.9 to -2.0) for CPAP compared to control, with a greater effect in patients with a higher baseline ESS score.
Qaseem 24 reported a pooled reduction in sleepiness of -2.37 points ESS (95% 95% CI -3.23, -1.51) for CPAP compared to control and of -2.5 (95% CI -3.5, -1.5) for CPAP compared to sham CPAP.
Clinically relevant decrease in sleepiness is 2 points ESS.
| Quality of life
Moderate-High GRADE |
Patil 23 reported, based on 19 included RCTs, a clinically significant improvement in sleep-related quality of life, but not overall QOL in adults with OSA.
Campos-Rodriquez 3 reported a significant improvement in quality of life, as measured with the Quebec Sleep Questionnaire (QSQ), for CPAP compared to control.
Qaseem 24 reported, based on 7 included studies, no significant effect of CPAP when compared to control on quality of life, as measured with the Short Form (36) Health Survey (SF36).
Mood – depression and anxiety | CPAP, when compared to control, leads to an improvement in mood, including depression and anxiety 31 |
| Cognitive functioning
Low GRADE |
Qaseem 24 reported a significant effect of CPAP when compared to control on 11 comparisons (5 studies) out of 82 comparisons (15 studies) of cognitive functioning. Pan 39(13 included studies), Kylstra 16 reported no significant effect of CPAP when compared to control on cognitive functioning - there was a slight trend towards improvement in some cognitive domains after treatment with CPAP.
Table. Auto vs. fixed CPAP
| Apnoea- hypopnoea index (AHI)
Moderate GRADE | |
| Sleepiness (Epworth sleepiness scale (ESS))
Moderate GRADE | |
| Quality of life
Low GRADE |
Table. CPAP vs. mandibular advancement splint (MAS)
| Apnoea-hypopnoea index (AHI)
Moderate GRADE | CPAP, when compared to MAS, reduces AHI to a greater extent 26,21,5,17, Medical Advisory Secretary Ontario 2009 |
| Sleepiness (Epworth sleepiness scale (ESS)) Moderate GRADE |
Efficacy of CPAP on Co-morbidities
While a previous observational study demonstrated a decrease in the incidence of fatal and non-fatal cardiac events in men with severe OSA treated with CPAP , as well as a reduction in the incidence of fatal events from the levels observed in those with untreated severe OSA compared to that of control subjects and snorers over a 10 year period 19, the more recent SAVE study (randomised controlled study of CPAP for secondary prevention of cardiovascular events in moderate to severe OSA), did not show a reduction in mortality or cardiovascular events with CPAP 20. However, improvements in daytime sleepiness, quality of life, mood and work attendance were observed 19,20.
Table. Effects of CPAP on co-morbidities
| Blood pressure
Moderate GRADE | |
| Cerebrovascular accident (CVA) | |
| Cardiovascular events |
Patil 23 reported that the meta-analysis did not demonstrate a clinically significant reduction in all-cause mortality with the use of PAP. Several large trials showed no clinically significant impact of CPAP therapy on cardiovascular morbidity and mortality.
| Atrial fibrillation
Low GRADE | CPAP treatment may reduce the risk of atrial fibrillation recurrence in OSA patients 27 |
| Mortality
Very low GRADE | |
| Glucose metabolism
High GRADE |
Patil 23 reported that analyses do not support that CPAP reduces fasting glucose or haemoglobin A1c (HbA1C) in adults with OSA with or without type 2 diabetes mellitus.
The Sleep Apnea Cardiovascular Endpoints (SAVE) trial 18 concluded that there is no evidence that CPAP therapy over several years affects glycaemic control in those with diabetes or prediabetes or diabetes risk over standard-of-care treatment.
The GRADE system
The Grading of Recommendations Assessment, Development and Evaluation (GRADE) system provides a transparent approach to grading quality (or certainty) of evidence and strength of recommendations. Many international organizations have provided input into the development of the GRADE approach which is now considered the standard in guideline development.
The OSA resource’s treatment-options GRADE-evidence ratings are based on the recommendations of the Dutch Medical Specialists Federation ‘Federatie Medisch Specialisten (www.kennisinstituut.nl)’ published in ‘Obstructief slaapapneu (OSA) bij volwassenen’ on June 1st 2018 (https://richtlijnendatabase.nl). And the American Academy of Sleep Medicine’s most recent meta-analysis and GRADE assessment on the effectiveness of CPAP. 23
Further clinical practice guidelines for the management of OSA in adults reviewed include the American Academy of Sleep Medicine (AASM) 23, the American Thoracic Society (ATS) 40, 41, the American Cllege of Physicians (ACP) 24, the Canadian Thoracic Society 42 and the International Geriatric Sleep Medicine Taskforce.43
AHI - Apnoea-Hypopnoea Index
BBTi - Brief Behavioural Therapy for Insomnia
BMI - Body Mass Index (kg/m2)
BQ - Berlin Questionnaire
CBTi - Cognitive Behavioural Therapy for Insomnia
CELL - Coblation Endoscopic Lingual Lightening
COPD - Chronic Obstructive Pulmonary Disease
CVA - Cerebrovascular Accident
CPAP - Continuous Positive Airway Pressure
CSA - Central Sleep Apnoea
DASS - Depression Anxiety Stress Scale
DBAS - Dysfunctional Beliefs and Attitudes about Sleep
DBP - Diastolic Blood Pressure
DIMS - Difficulties Initiating and/or Maintaining Sleep
DISE - Drug-Induced Sleep Endoscopy
DISS - Daytime Insomnia Symptom Scale
ENT - Ear Nose and Throat
ESS - Epworth Sleepiness Scale
FOSQ - Functional Outcomes of Sleep Questionnaire
FSH - Follicle-Stimulating Hormone
FTP - Friedman Tong Position
GP - General Practitioner
HANDI - RACGP Handbook of Non-Drug Interventions
HGNS - Hypoglossal Herve Htimulation
ISI - Insomnia Severity Index
K10 - Kessler Psychological Distress Scale
MAD - Mandibular Advancement Device
MAS - Mandibular Advancement Rplint
MBS - Medicare Benefits Schedule
MMA - Maxillomandibular Advancement Surgery
MRA - Mandibular Repositioning Appliance
ODI - Oxygenation Desaturation Index
OSA - Obstructive Sleep Apnoea
PLMD - Periodic Limb Movement Disorder
PT - Positional Therapy
PTSD - Post-Traumatic Stress Disorder
PSG - Polysomnography
QSQ - Quebec Sleep Questionnaire
REM - Rapid Eye Movement
RFTB - Radiofrequency Thermotherapy of the Tongue Base
SBP - Systolic Blood Pressure
SCI - Sleep Condition Indicator
SE - Sleep Efficiency
SF36 - Short-Form (36) Health Survey
SMILE - Submucosal Minimally Invasive Lingual Excision
SNRIs - Serotonin-Norepinephrine Reuptake Inhibitors
SOL - Sleep Onset Latency
SSRI - Selective Serotonin Reuptake Inhibitors
TFTs - Thyroid Function Tests
TIB - Time In Bed
TORS - Transoral Robotic Surgery
TST - Total Sleep Time
UPPP - Uvulopalatopharyngoplasty
WASO - Wake After Sleep Onset