An automatic positive airway pressure device (APAP, AutoPAP, AutoCPAP) automatically titrates, or tunes, the amount of pressure delivered to the patient to the minimum required to maintain an unobstructed airway on a breath-by-breath basis by measuring the resistance in the patient’s breathing, thereby giving the patient the precise pressure required at a given moment and avoiding the compromise of fixed pressure.
BiPAP machines are recommended for people with heart problems and diseases with their lungs. Since these patients have difficulties in breathing both inhalation and exhalation need to be supported with a machine. Therefore, you use a BPAP machine on them instead of a CPAP machine. The specialty with a BiPAP machine is that it provides two different pressures; one at the time of inhalation and one when the patient exhales.
Pressure is measured by water column in centimeters. A BiPAP machine uses two pressures. When the patient inhales it delivers air at a pressure of around 30 cm of water while at exhalation it delivers close to 20 cm. In contrast, a CPAP machine delivers air at a constant pressure of between 4 and 20 cm of water column.
While doctors could prescribe heart patients and those who suffer serious respiratory diseases to use BiPAP machines, before recommending the use of CPAP machines they always conduct a polysomnogrphy test on sleep apnea patients.