Non-Invasive Ventilation Modalities and Applications

Primary NIV Modalities

The American Thoracic Society recommends CPAP, which delivers a single constant positive pressure throughout the entire respiratory cycle, maintaining the same pressure during both inspiration and expiration, for patients with cardiogenic pulmonary edema, chest wall trauma with hypoxemia, and diffuse pneumonia 1, 3
BiPAP provides two distinct pressure levels: higher inspiratory positive airway pressure (IPAP) during inspiration and lower expiratory positive airway pressure (EPAP) during expiration, and is more effective than CPAP for hypercapnic respiratory failure and patients who cannot tolerate high CPAP pressures 2, 3

The European Respiratory Society suggests Assisted Spontaneous Breathing (Pressure Support Ventilation), where the patient's respiratory effort triggers the ventilator both on and off, with the patient determining respiratory frequency and timing of each breath, for patients who require ventilatory support 2, 4, 5
Assist/Control Ventilation (ACV) delivers a preset number of mandatory breaths per minute in the absence of patient effort while allowing patient-triggered breaths, and is preferable to pressure support for patients at risk of hypoventilation 2, 6, 5
Controlled Mechanical Ventilation (CMV) provides full ventilatory support with no patient effort required, delivering preset breaths at fixed intervals regardless of patient respiratory drive, and is used for patients who require full ventilatory support 8, 4, 5

The American College of Cardiology recommends Adaptive Servo-Ventilation (ASV), a positive airway pressure therapy in which air pressure target is adjusted according to the patient's breathing patterns, for patients with central sleep apnea, mixed apneas, and complex sleep apnea, but warns against its use in patients with NYHA class II-IV heart failure with reduced ejection fraction and central sleep apnea 9

The British Thoracic Society notes that BiPAP ventilators are simpler to use, cheaper, and more flexible than other ventilator types, and have been used in the majority of randomized controlled trials of NIV 3
The American Thoracic Society warns that terminology for ventilation modes varies significantly between ventilator manufacturers, potentially causing confusion in clinical practice 2, 6, 5
Contraindications for NIV include recent facial or upper airway surgery, facial abnormalities or fixed upper airway obstruction, vomiting patients, impaired consciousness, severe hypoxemia, and copious respiratory secretions 1, 3, 10