CPAP (Continuous positive airway pressure) is the use of continuous positive pressure to maintain a continuous level of positive airway pressure, in a spontaneously breathing Pt.

• Functionally the same as PEEP (Positive End Expiratory Pressure), as both are used to stent alveoli open, and recruit alveoli of the lungs for more surface area for ventilation
• CPAP is continuous positive airway pressure, using constant mild air pressure to keep an airway open, maintaining a constant PEEP, rather than only at end expiration (cycling)
• Patients must initiate all of their breaths
• CPAP machines can be used at home
• Some CPAP have other features, including heated humidifiers
• CPAP delivery through nasal mask is the most common modality, but there are other interfaces, including including oral/naso-oral masks (used when nasal congestion/obstruction is an issue)

BiPAP (Bilevel positive airway pressure) is a mod of CPAP, that uses time-cycled or flow-cycled change between 2 different applied levels of positive airway pressure (cf CPAP which uses a SINGLE level of positive airway pressure throughtout the whole respiratory cycle). It generates inspiratory (IPAP) and expiratory (EPAP) pressure gradients that complement the Pt's own respiratory cycle, optimizing the lung's efficiency, and reducing the WOB.

• Typically used in Pt's who have breathing problems (e.g. sleep apnea), preventing the airways from collapsing or becoming blocked
• Frequently used in preterm infants whose lungs have not fully developed (e.g. respiratory distress syndrome), as it is associated with improved survival, decreased need for steroid Tx, and a decrease in incidence of bronchopulmonary dysplasia. Its use is nonetheless controversial

• Nasal CPAP reduces ventilator time
• Nasal CPAP increases occurence of pneumothorax

• Mechanical ventilation
• High flow oxygen
• Life support