CPAP vs. BiPAP
CPAP (Continuous Positive Airway Pressure):
- Mechanism: Delivers a constant, steady pressure throughout the entire respiratory cycle, helping to keep the airways open
- Indications: Often used for patients with obstructive sleep apnea, congestive heart failure, or other conditions where airway collapse is a concern
- Settings: The primary setting is the pressure level (measured in cm H₂O), which is typically adjusted to the patient’s needs
BiPAP (Bilevel Positive Airway Pressure):
- Mechanism: Provides two levels of pressure: a higher pressure during inspiration (IPAP) and a lower pressure during expiration (EPAP)
- Indications: Suitable for patients with conditions such as COPD exacerbations, acute pulmonary edema, and hypercapnic respiratory failure, where both ventilation and oxygenation need support
- Settings:
- IPAP (Inspiratory Positive Airway Pressure): Controls the level of pressure during inhalation, aiding in overcoming airway resistance and improving ventilation
- EPAP (Expiratory Positive Airway Pressure): Maintains airway patency during exhalation, similar to PEEP
- FiO₂ (Fraction of Inspired Oxygen): Adjusted to meet oxygenation requirements
Reporting BiPAP Settings and Interpretation
- IPAP and EPAP: Expressed as IPAP/EPAP (e.g., 15/5 cm H₂O), indicating the pressures during inspiration and expiration, respectively
- FiO₂: Specify the percentage of oxygen being delivered
- Mode: Indicate if the machine is set to spontaneous (S), timed (T), or spontaneous/timed (S/T) mode
Interpretation of BiPAP Settings:
- High IPAP: Typically used in cases requiring increased ventilatory support, such as in hypercapnic respiratory failure
- Low EPAP: A lower EPAP can be beneficial for patients with hypoxemia without significant hypercapnia
- FiO₂ Adjustments: Aim for the lowest FiO₂ that maintains adequate oxygenation to reduce the risk of oxygen toxicity