Bilevel ventilators were developed by modifying CPAP to also provide inspiratory positive airway pressure (IPAP) to assist inspiration (breathing in). IPAP and expiratory positive airway pressure (EPAP) settings are adjusted separately. People with neuromuscular disease and weak diaphragmatic muscles often may have difficulty breathing in and need IPAP set higher than EPAP, e.g., an IPAP of 14 and an EPAP of 3. The difference between IPAP and EPAP is called the span, and in these cases should be at least 10.
Bilevel units are made by several manufacturers and are often generically referred to as BiPAP. The only bilevels that can be called BiPAP® are the units patented and registered by one manufacturer.
Bilevels are used primarily at night with a nasal, facial or oral mask, or nasal pillows. Some people use them continuously, but there is no FDA approval for such use in the home. (An alternative for 24-hour use is a volume-cycled ventilator ). The FDA has not approved them for off-label use by people with tracheostomies, although some physicians prescribe them, particularly for infants and children.
Three modes are available with bilevel ventilators:
"S" or spontaneous breathing patterns that are sensed so that the unit switches between prescribed pressures;
"T" or timed mode that delivers IPAP and EPAP at a predetermined breathing rate;
"S/T" or spontaneous/timed that operates in spontaneous mode, but switches to timed mode (referred to as a backup rate) when breaths are not initiated by the individual.
People with neuromuscular disease should use a bilevel ventilator with a backup rate that can initiate breaths, particularly at night.
Bilevel units are made by several manufacturers and are often generically referred to as BiPAP. The only bilevels that can be called BiPAP® are the units patented and registered by one manufacturer.
Bilevels are used primarily at night with a nasal, facial or oral mask, or nasal pillows. Some people use them continuously, but there is no FDA approval for such use in the home. (An alternative for 24-hour use is a volume-cycled ventilator ). The FDA has not approved them for off-label use by people with tracheostomies, although some physicians prescribe them, particularly for infants and children.
Three modes are available with bilevel ventilators:
"S" or spontaneous breathing patterns that are sensed so that the unit switches between prescribed pressures;
"T" or timed mode that delivers IPAP and EPAP at a predetermined breathing rate;
"S/T" or spontaneous/timed that operates in spontaneous mode, but switches to timed mode (referred to as a backup rate) when breaths are not initiated by the individual.
People with neuromuscular disease should use a bilevel ventilator with a backup rate that can initiate breaths, particularly at night.