PAP (positive airway pressure) therapy treats obstructive sleep apnea by delivering pressurized air into the airways to keep it open during the night while sleeping. PAP can reduce or completely eliminate sleep apnea (learn more about how PAP therapy works here).
There is significant evidence that treating sleep apnea with PAP therapy improves quality of life, reduces daytime sleepiness, reduces motor-vehicle accidents, improves hypertension and may reduce death due to cardiovascular events.
The most common device is called CPAP; however, there is another device called bi-level PAP or BiPAP that can be more comfortable for some patients. Learn more about how that device works and what’s required to get approval from your insurance company.
How is a treating PAP pressure determined?
The pressure that is needed to treat a patient’s sleep apnea is usually determined during a titration sleep study, a type of polysomnography that is performed in a sleep center. The patient is hooked up to electrodes to measure her sleep and wears a PAP mask to sleep (learn more about the different types of sleep studies here).
For most patients, a CPAP will be used. The “C” stands for continuous. A CPAP machine blows air at one continuous pressure.
Once asleep, the sleep technician will monitor her sleep, track her apneas and adjust the pressure that is being delivered. Typically, as the pressure is increased, apneas will decrease. The goal of the titration study is to find the lowest pressure that will eliminate all or most of the breathing events. The technician may increase and later decrease the pressure. Once the data is scored and reviewed by a physician, a treating CPAP pressure can be determined.
Some patients with severe sleep apnea (learn more about the differences between mild, moderate and severe sleep apnea here) will need higher air pressure to keep the airway open. If the pressure gets very high the patient may be uncomfortable. In some cases, a two-level PAP device, called a bi-level or BiPAP device can be used.
How does bi-level PAP work?
Bi-level PAP delivers two different pressures of air: a higher pressure when the patient breathes in and a lower pressure when she breathes out. This lower pressure reduces the resistance and relieves the abdominal muscles, both of which can make the patient more comfortable.
The patient will also be titrated on this device to find the treating pressure that reduce or eliminate all events. The maximum inspiratory (breathing in) pressure on bi-level shouldn’t exceed 30 cm H20 and difference between the inspiratory (breathing in) and expiratory (breathing out) pressures should not be less than 4 cm H20.
In general, a patient could be transitioned from CPAP to Bi-level when the CPAP pressure approaches 15 cm H2O. Exhaling against this CPAP pressure can be uncomfortable for most patients.
Aside from discomfort from PAP pressure, there is another subset of patients that may benefit from the use of bi-level therapy to time their breathing during night.
Why aren’t all patients put on bi-level PAP?
Bi-level PAP is usually reserved for patients requiring higher pressures because CPAP is sufficient for most patients with lower pressure requirements.
Additionally, because the bi-level machine is more sophisiticated, it is more expensive than CPAP. In Southern California, Blue Cross reimburses around $475 for CPAP and $1,100 for a bi-level PAP machine (learn more about how insurance companies pay for PAP therapy here). Insurance companies require proof that the patient attempted CPAP therapy before they will cover the more expensive bi-level machine.
Even though bi-level is more comfortable for some patients, recent studies have not shown that it leads to better adherence to therapy over CPAP.
When will insurance cover bi-level PAP?
Insurance companies will usually cover bi-level PAP if the patient has a diagnosis of obstructive sleep apnea and has shown “intolerance” using CPAP therapy. The patient may have been previously dispensed a CPAP device or may have merely attempted CPAP therapy during an in-center titration and was uncomfortable due to increasing pressure approaching or exceeding 15 cm H2O.
Medicare has clearly defined coverage cirteria for sleep studies and PAP devices. More commercial and HMO insurance plans are following Medicare guidelines. We have outlined their guidelines for bi-level PAP below:
Medicare will cover a bi-level respiratory assist device without backup (this is what they call a bi-level or BiPAP) for patients with obstructive sleep apnea if the patient meets the criteria for PAP therapy:
- AHI or RDI > 15 events per hour with a minimum of 30 events or
- AHI or RDI > 5 to14 events per hour with a minimum of 10 events recorded and documentation of:
- Excessive daytime sleepiness, impaired cognition, mood disorders or insomnia; or
- Hypertension, ischemic heart disease or history of stroke
and:
- CPAP is tried and proven ineffective based on therapeutic trial conducted in either a facility (sleep center) or home setting.
- A face-to-face clinical re-evaluation is completed during the 3-month trial period. The physician must document that the following issues were addressed prior to changing from CPAP:
- Mask fit and comfort (read more about different types of mask and how they fit here)
- CPAP pressure setting prevent tolerating therapy and lower settings were tried, but failed to:
- Control symptoms of OSA; or
- Improve sleep; or
- Reduce AHI/RDI to acceptable levels
If the patient switches to a bi-level device within the 3-month trial, the length of the trial is not changed as long as there are at least 30 days remaining. If less than 30 days remain of the trial period, re-evaluation must occur before the 120th day (following the same criteria as CPAP adherence).
Read more about Medicare coverage for PAP and supplies here.
Do you have sleep apnea and need a PAP device? We are contracted with most payers in Southern California (see our full list here).
Sources:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3119924/
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