CPAP vs APAP vs BiPAP vs ASV
PAP devices differ in how they set pressure. Which one you use is a prescribing decision; this table explains what each type does.
| Device type | How pressure works | Typical use | Medicare code | Things to know |
|---|---|---|---|---|
| CPAP (fixed) | One steady pressure all night, set by your clinician. | Obstructive sleep apnea; the standard first treatment. | E0601 | Comfort features such as ramp and EPR or Flex soften the pressure without changing the prescription. |
| APAP (auto CPAP) | Adjusts breath by breath within a minimum and maximum range set by your clinician, responding to detected apneas, flow limitation and snoring. | Obstructive sleep apnea, including home titration. | E0601 | Medicare bills auto-adjusting single-level devices under the same code as fixed CPAP. Most current home machines can run in either CPAP or auto mode. |
| Bilevel (BiPAP, BPAP) without backup rate | Two pressures: higher when breathing in (IPAP), lower when breathing out (EPAP). | OSA when CPAP has been tried and not tolerated or not effective; some other breathing conditions. | E0470 | For OSA, Medicare covers E0470 only after an E0601 has been tried and proven ineffective. |
| Bilevel with backup rate (S/T) | Two pressures plus timed breaths if you do not breathe on your own within a set time. | Central breathing problems and hypoventilation conditions under specialist care. | E0471 | Prescribed and set up by specialists; coverage criteria differ from OSA. |
| ASV (adaptive servo-ventilation) | Varies pressure support breath by breath to stabilize breathing, on top of an expiratory pressure. | Central sleep apnea, including Cheyne-Stokes respiration and complex sleep apnea. | Ask your supplier | In the SERVE-HF trial (2015), patients with heart failure, an ejection fraction of 45% or less and predominantly central apnea had higher all-cause and cardiovascular mortality on ASV. Heart function needs to be assessed before ASV is prescribed. |
Notes
- NHLBI describes CPAP as constant pressure, bilevel PAP as different pressures for breathing in and out, and APAP as automatically adjusting pressure during sleep.
- Never change your prescribed mode or pressure yourself. Talk to your prescribing clinician if therapy is not working.
- BiPAP is a Philips trademark that is widely used for all bilevel devices.
Sources
- https://www.nhlbi.nih.gov/health/sleep-apnea/treatment
- https://medlineplus.gov/ency/article/001916.htm
- https://www.cms.gov/medicare-coverage-database/view/article.aspx?articleid=52467
- https://www.cms.gov/medicare-coverage-database/view/lcd.aspx?lcdid=33718
- https://pmc.ncbi.nlm.nih.gov/articles/PMC4779593/
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