BiPAP vs CPAP: Which Machine, for Which Condition, at Home
CPAP gives one steady pressure that keeps the airway open and is the machine for obstructive sleep apnoea. BiPAP gives a higher pressure when you breathe in and a lower one when you breathe out, and is prescribed when the lungs themselves need help — COPD, neuromuscular weakness, obesity-related breathing failure, some heart failure. They are not interchangeable, the doctor chooses, and each is set to a written prescription before it is used.
What each one does
In sleep apnoea the airway collapses; a single continuous pressure splints it open, and that is CPAP. In COPD or muscle weakness the airway is open but the lungs cannot move enough air; BiPAP pushes air in on inhalation and drops the pressure on exhalation so breathing out is not a fight. Some BiPAP machines also deliver a backup rate — breaths on a timer if the patient pauses — which is why they are used for more serious conditions.
Which conditions, which machine
- Obstructive sleep apnoea: CPAP, or auto-CPAP within a prescribed range.
- COPD with high carbon dioxide, especially after a hospital admission: BiPAP.
- Neuromuscular disease (motor neurone disease, muscular dystrophy): BiPAP, often with a backup rate.
- Obesity hypoventilation: usually BiPAP.
- Heart failure with certain breathing patterns: the cardiologist decides; sometimes BiPAP, sometimes neither.
The prescription each needs
CPAP: the pressure (or the range for an auto machine) from a sleep study. BiPAP: the inhale pressure (IPAP), the exhale pressure (EPAP), the backup rate if any, and the hours of use — from a respiratory physician. The rental supplier sets the machine to those numbers at installation and locks them; the family does not adjust.
Masks, humidifiers and getting used to it
Mask fit matters more than the machine. Nasal pillows, a nasal mask or a full-face mask — a mouth-breather needs the full-face one. Use the humidifier; dry air is the commonest reason people stop. Give it two to three weeks of short evening trials before judging. A nurse visit can check the mask, the skin under it and comfort; that is part of a nursing plan.
Rent or buy
Rent first, for one to three months, while the mask and the routine settle; then buy if it will be nightly for years. Both machines are on monthly rent from Eldrly, delivered, set to the prescription and demonstrated, with masks and filters as consumables.
Frequently asked questions
Can I use a CPAP instead of a BiPAP?
No. If BiPAP was prescribed the lungs need two pressures and a CPAP will not provide them. If CPAP was prescribed, a BiPAP is unnecessary and the wrong settings can harm.
Is BiPAP a ventilator?
It is non-invasive ventilation — support through a mask, not a tube. It is not the same as an ICU ventilator and is not used for a patient who cannot protect their own airway.
Do I need a sleep study for CPAP?
Yes. The pressure comes from the study. An auto-CPAP still needs a prescribed range.
How much does it cost to rent?
The live monthly prices for BiPAP and CPAP, delivered and installed, are on Eldrly’s equipment pages.