From the Guidelines
Optimal CPAP pressure settings should be determined through a titration process that aims to eliminate respiratory events while maintaining patient comfort, with a recommended starting pressure of 4 cm H2O and gradual increases until obstructive events are eliminated, as recommended by the American Academy of Sleep Medicine 1. The titration process involves increasing CPAP pressure until apneas, hypopneas, respiratory effort-related arousals (RERAs), and snoring are eliminated, or the recommended maximum CPAP is reached 1. Key considerations in determining optimal CPAP pressure settings include:
- Starting with a minimum pressure of 4 cm H2O for pediatric and adult patients 1
- Gradually increasing pressure by 1-2 cm H2O every 15-30 minutes until obstructive events are eliminated
- Exploring CPAP pressures above the level that achieves control of respiratory parameters, but not exceeding 5 cm H2O above this level, to reduce residual upper airway resistance 1
- Monitoring for resolution of symptoms, reduction in the apnea-hypopnea index (AHI) to below 5 events per hour, and improvement in oxygen saturation levels to confirm effectiveness of pressure settings
- Prioritizing patient comfort to ensure long-term compliance with therapy, with the goal of using the lowest effective pressure.
From the Research
Determining Optimal CPAP Pressure Settings
The guidelines for determining optimal Continuous Positive Airway Pressure (CPAP) pressure settings involve several factors and considerations. According to 2, treatment algorithms should aim to eliminate apneas, hypopneas, snoring, significant O2 desaturations, and EEG arousals.
- Key factors to consider:
- Apnea/hypopnea index
- Body mass index
- Neck circumference
- Severity of sleep apnea
- Presence of collapsible pharynx
Methods for Determining Optimal Pressure
Different methods can be used to determine the optimal CPAP pressure, including:
- Split-night polysomnogram
- Unattended auto-CPAP titration
- Full-night polysomnogram for patients with subtle OSA/H, underlying cardiopulmonary disease, or other forms of sleep-disordered breathing 3
Predicting Optimal CPAP Pressure
Research has shown that the optimal set of predictors for CPAPmin consists of apnea/hypopnea index, body mass index, and neck circumference, accounting for 76% of the variability in CPAP 4.
- Other considerations:
- Patient comfort and tolerance
- Presence of co-morbidities, such as obesity hypoventilation syndrome and COPD
- Need for adjustments to CPAP pressure over time
Alternative Therapies
For patients who fail CPAP therapy, alternative therapies such as bilevel positive airway pressure (BPAP) may be effective, particularly for obese patients with moderate to severe OSA 5. Automatically adjusting CPAP may also provide a new therapeutic option, but requires careful evaluation to define improvements in ease of titration, effectiveness, and ultimate compliance 2.