Therapeutic Efficacy:How Effective is CPAP?
It is customary to hear that Continuous Positive Airway Pressure (CPAP) is close to 100% effective. However, a more accurate assessment of CPAP effectiveness must consider patient compliance; how often and how long it is used.
GROTE et al, Eur Respir J 2000;16(5):921-7 designed a study of 209 patients to determine overall long-term true effectiveness of Treatment after CPAP therapy. They were followed up at 9, 18 and 30 months after initial prescription.
The authors concluded that the effectiveness of CPAP therapy is potentially high, but acceptance is low. Accounting for sleep-time, its actual effect and use, “50% adjusted CPAP effectiveness” was observed. Interestingly, the authors found no difference in characteristics between those patients compliant and those non-compliant to CPAP therapy; making patient selection very difficult.
Airway Orthotics are not recommended as First Line Therapy for Mild and Moderate Sleep Apnea because they are superior to CPAP in eliminating Apnea, clearly they are not. However, when it comes to compliance Airway Orthotics win hands down; a factor that must be considered.
A question often asked about Airway Orthotics is, “Do they work?” Lowe et al., Sleep. Vol 23, 2000 conducted a study to shed some light on this issue. It was designed to measure the effects of Airway Orthotics on Airway Size, Obstructive Sleep Apnea (OSA) and to evaluate it’s Compliance.
It involved pre and post sleep studies for 38 OSA patients of varying severity. Compliance was measured using temperature sensitive monitors that were imbedded in the acrylic appliances.
The mean Repiratory Disturbance Index (RDI) was reduced from 32.6 to 12.1 with the Orthotic. Eighty percent of the moderate OSA (15-30) patients and sixty-one percent of the severe OSA (>30) patients experienced a reduction in RDI to below 15.
Using fibre-optic video endoscopy, it was found that airway size at the level of the velopharynx was significantly increased in cross section.
Compliance data demonstrated that the average wear-time was 6.8 hours with a range between 5.6 and 7.5 hours per night.
This study clearly demonstrates that oral appliances dilate the airway, are well tolerated and effectively treat 80% of patients with mild to moderate OSA.
Airway Orthotics don’t work 100% of the time, but even in those cases they usually provide a remarkable improvement; leaving the “CPAP non-compliant” patient much better off.
Canadian Sleep Medicine Today
One million individuals in Ontario currently suffer from some level of apnea. If they all came forward, it would take over 10 years to assess the severity of their problem with a full night sleep study, and an equal length of time to conduct a CPAP trial. These patients would typically be offered CPAP as first line treatment. Six months later, 60 % of them would remain compliant with this prescribed treatment, leaving over 400,000 untreated.
Health caregivers for these patients can best serve them by collaborating and developing a true multi-disciplinary approach; one that utilizes efficient screening processes, effectively provides information regarding lifestyle changes that improves the severity of their disease, and guides the patients towards “patient specific therapy alternatives” that have proven effectiveness and favorable compliance rates based on the most current research available.
John Viviano B.Sc. DDS Diplomate ABDSM; obtained his credentials from U of T in 1983, he provides conservative therapy for snoring and sleep apnea in his Clinic Limited to the Management of Breathing Related Sleep Disorders. A member of various sleep organizations, he is a Credentialed Diplomate of the American Board of Dental Sleep Medicine, and has lectured internationally regarding management of Sleep-Disordered Breathing and the use of Acoustic Reflection. Dr Viviano has also conducted original research, authored articles and established protocols on the use of Acoustic Reflection for assessing the Upper Airway and its Normalization.