From the Guidelines
For COPD exacerbation, Bi-level Positive Airway Pressure (BiPAP) is the preferred treatment over Continuous Positive Airway Pressure (CPAP), as it is strongly recommended by clinical guidelines for patients with acute or acute-on-chronic respiratory acidosis due to COPD exacerbation 1.
Rationale for BiPAP Use
The use of BiPAP in COPD exacerbation is supported by high certainty of evidence, which indicates its effectiveness in managing acute respiratory failure leading to acidosis [pH ⩽7.35] 1. BiPAP delivers two different pressure levels - a higher pressure during inhalation (IPAP) and a lower pressure during exhalation (EPAP) - which helps in reducing the work of breathing, improving ventilation, and decreasing carbon dioxide retention.
Key Considerations for BiPAP Settings
- Initial settings for BiPAP may include an IPAP of 10-15 cmH2O and EPAP of 4-6 cmH2O.
- Adjustments should be based on patient response and arterial blood gases.
- The goal is to improve ventilation and reduce hypercapnia without causing undue discomfort or increasing the risk of other complications.
Patient Selection for BiPAP
BiPAP should be considered for patients with moderate to severe COPD exacerbations who show signs of respiratory distress, particularly those with hypercapnic respiratory failure (PaCO2 > 45 mmHg) and respiratory acidosis (pH < 7.35), but who remain alert enough to protect their airway 1. It is also recommended for patients considered to require endotracheal intubation and mechanical ventilation, unless the patient is immediately deteriorating 1.
Comparison with CPAP
CPAP, which delivers constant pressure throughout the respiratory cycle, is not as effective as BiPAP for COPD exacerbations because it can increase the work of breathing in these patients and does not assist with ventilation as effectively. Therefore, BiPAP is the preferred choice for managing COPD exacerbations requiring non-invasive ventilation 1.
From the Research
Use of CPAP and BiPAP in COPD Exacerbation
- CPAP and BiPAP are forms of non-invasive ventilation (NIV) that can be used to manage acute respiratory failure due to COPD exacerbation 2, 3, 4, 5, 6.
- BiPAP has been shown to be effective in reducing respiratory rate, heart rate, and improving arterial blood gas parameters in patients with COPD exacerbation 4.
- NIV, including BiPAP, has been recommended as a first-line treatment for patients with severe COPD exacerbation, as it can reduce the need for intubation and improve survival 3, 5.
- CPAP and BiPAP can be used in different settings, including intensive care units and general medical wards, depending on the severity of the patient's condition and the availability of resources 5, 6.
Comparison of CPAP and BiPAP
- A study comparing the effectiveness of CPAP and BiPAP in patients with acute heart failure syndromes and acute exacerbations of COPD found that both treatments were effective in improving respiratory and vital parameters, but the algorithm for titrating non-invasive ventilation pressure differed between the two conditions 6.
- BiPAP was found to be more effective than CPAP in reducing PaCO2 levels and improving pH in patients with COPD exacerbation 4.
Clinical Guidelines
- Clinical guidelines recommend the use of NIV, including BiPAP, as a first-line treatment for patients with severe COPD exacerbation, and suggest that CPAP may also be used in certain situations 2, 5.
- The choice between CPAP and BiPAP should be based on individual patient needs and the availability of resources, and should be guided by clinical experience and evidence-based practice 2, 5.