BCV for Acute Respiratory Failure (ARF)
Respiratory failure is a syndrome in which the respiratory system fails in one or both of its gas exchange functions: oxygenation and carbon dioxide elimination. In practice, it may be classified as either hypoxemic or hypercapnic.
Hypoxemic respiratory failure (type I) is characterized by an arterial oxygen tension (PaO2) lower than 60 mm Hg with a normal or low arterial carbon dioxide tension (PaCO2). This is the most common form of respiratory failure, and it can be associated with virtually all acute diseases of the lung, which generally involve fluid filling or collapse of alveolar units. Some examples of type I respiratory failure are cardiogenic or noncardiogenic pulmonary edema, pneumonia, and pulmonary hemorrhage.
Hypercapnic respiratory failure (type II) is characterized by a PaCO2 higher than 50 mm Hg. Hypoxemia is common in patients with hypercapnic respiratory failure who are breathing room air. The pH depends on the level of bicarbonate, which, in turn, is dependent on the duration of hypercapnia Common etiologies include drug overdose, neuromuscular disease, chest wall abnormalities, and severe airway disorders.
In respiratory failure, mechanical ventilation is used for 2 essential reasons: (1) to increase Pa O2 and (2) to lower Pa CO2. Mechanical ventilation also rests the respiratory muscles and is an appropriate therapy for respiratory muscle fatigue.
BCV is a proven option that allows these goals to be obtained through a more physiologic approach while not requiring an artificial airway.
BCV allows patient comfort and decreases risks from invasive positive pressure ventilation.