What is BiPAP (Positive Bipressure System)?

The term BiPAP is used colloquially to refer to a mechanical ventilation system used as temporary respiratory support in patients with respiratory distress. The real acronyms are BPAP, from the English Bilevel Positive Airway Pressure. In Spanish it is known as Bi-Level Positive Airway Pressure or Positive Bi-Pressure Systemalthough the acronym BiPAP is also generally used.

It is important to point out that the term BiPAP, although used in a general way, is a registered trademark of Philips Respironics. The rest of the manufacturers of positive bipressure systems use the acronym BPAP.

How does it work?

The BiPAP system was developed in the 1990s as improvement of mechanical ventilation systems with continuous positive pressure (CPAP – Continuous Positive Airway Pressure). Both CPAP and BiPAP are non-invasive mechanical ventilation systems (they do not use endotracheal or tracheostomy tubes) that are based on the creation of an air flow that generates positive intrathoracic pressure.

The difference between CPAP and BiPAP is that the latter generates two different levels of intrathoracic pressurea pressure level during expiration (EPAP – Positive Expiratory Pressure) and another pressure level during inspiration (IPAP – Inspiratory Positive Pressure). Positive air pressure keeps the airways open, facilitating breathing, and is exerted through a mask that is placed over the patient's nose and/or mouth.

When using a CPAP system, by maintaining continuous pressure, the patient has to exhale against the extra pressure exerted by the device, which is not suitable for all patients, for example those with neuromuscular disorders. This inconvenience is eliminated in BiPAP systems that allow two different and independent pressures to be established, one for inhalation and the other for exhalation. This dual configuration also makes it possible for the volume of air inhaled and exhaled to be greater.

The air supplied through the mask may or may not be enriched in Otwo according to the situation and characteristics of the patient.

When is BiPAP used?

BiPAP devices are used in a wide variety of cases where there is present respiratory distress. In general, invasive systems are used when breathing cannot be performed by the patient himself, while non-invasive systems such as BiPAP are used in cases of dyspnea and respiratory failure with the aim of reducing the pathophysiology and reducing the work of breathing.

BPAP systems have proven to be especially useful in patients with acute respiratory failure, hypoxemic respiratory failure, and patients with post-extubation failure. They may also be useful in patients where intubation is not possible.

Some of the most common situations in which it is used are heart failure, pneumonia, chronic obstructive pulmonary disease (COPD), asthma and asthmatic states, all of which are conditions that can occur with dyspnoea and result in blood levels of COtwo above normal. Patients with atelectasis (collapse of parts of the lung) and, in general, lung problems (cancer, etc.), can also benefit from positive bipressure systems, improving their situation.

The Sleep apnea It may be the situation best known to all in which the BiPAP in the home setting. Sleep apnea is a disease characterized by pauses in breathing or shallow breathing during sleep. The use of CPAP and BiPAP devices during sleep is currently one of the most effective treatments to improve the situation of these patients.

Before using a BiPAP device, some tests are carried out to determine its need, suitability and pressure settings. Some of the most common are the measurement of blood oxygen and carbon dioxide and respiratory rate. Some situations require special tests; for example, sleep apnea requires measurement of respiratory parameters overnight while the patient sleeps.


BiPAP systems, and non-invasive mechanical ventilation systems in general, are contraindicated in the following situations:

  1. Mask intolerance
  2. Unconsciousness/low level of consciousness
  3. Pneumothorax
  4. facial trauma
  5. Unstable breathing pattern
  6. intracranial hypertension
  7. Acute ischemic heart disease
  8. digestive bleeding
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