What is the initial setting for Continuous Positive Airway Pressure (CPAP) therapy?

Initial CPAP Settings for Obstructive Sleep Apnea

Start CPAP at 4 cm H₂O for all patients, regardless of age, and titrate upward in 1 cm H₂O increments at minimum 5-minute intervals until obstructive events are eliminated. 1

Starting Pressure

• Begin at 4 cm H₂O as the standard initial pressure for both pediatric and adult patients. 1
• Consider starting at a higher pressure (above 4 cm H₂O) in patients with elevated body mass index (BMI), as CPAP requirements correlate with BMI (ρ = 0.32, p <0.001). 1
• For patients undergoing retitration studies, a higher starting pressure than 4 cm H₂O may be appropriate. 1

Titration Algorithm During Sleep Study

Increase CPAP by at least 1 cm H₂O increments, waiting a minimum of 5 minutes between adjustments. 1

Specific triggers for pressure increases:

• Increase if ≥2 obstructive apneas occur in patients ≥12 years (or ≥1 apnea in patients <12 years). 1
• Increase if ≥3 hypopneas occur. 1
• Increase if ≥5 respiratory effort-related arousals (RERAs) occur. 1
• Increase if ≥3 minutes of loud or unambiguous snoring occurs in patients ≥12 years (or ≥1 minute in patients <12 years). 1

Maximum Pressure Limits

• Do not exceed 15 cm H₂O for patients <12 years. 1
• Do not exceed 20 cm H₂O for patients ≥12 years. 1

Critical Adjustments for Patient Tolerance

If the patient awakens complaining the pressure is too high, immediately restart at a lower pressure that allows comfortable return to sleep, then resume gradual titration. 1

This is essential for adherence, as skipping CPAP for 2 or more nights within the first week signals potential nonadherence. 2

When to Switch to BiPAP

Switch to BiPAP if obstructive events persist at 15 cm H₂O of CPAP or if the patient is intolerant of high CPAP pressures. 1

When switching to BiPAP:

• Start with IPAP 8 cm H₂O and EPAP 4 cm H₂O. 1, 3
• Maintain a minimum IPAP-EPAP differential of 4 cm H₂O. 1, 3

Down-Titration Considerations

Down-titration is not required but may be considered as an option. 2

The upper airway exhibits a hysteresis phenomenon, meaning that once an effective pressure is achieved, a lower pressure may maintain airway patency. 4 If implementing down-titration:

• Wait at least 30 minutes without obstructive respiratory events before decreasing pressure. 2
• Decrease IPAP by at least 1 cm H₂O with intervals no shorter than 10 minutes until obstructive events reemerge. 2
• Consider at least one "up-down" cycle during the night. 2

Common Pitfalls to Avoid

• Do not increase CPAP by increments >2.5 cm H₂O, as there is insufficient evidence supporting larger jumps. 1
• Do not wait <5 minutes between pressure adjustments, as this does not allow adequate time to assess response. 1
• For split-night studies, larger increments (2 or 2.5 cm H₂O) may be used given the shorter titration duration. 1

Follow-Up and Adherence Monitoring

PAP usage should be objectively monitored to help assure utilization. 2

• Close follow-up during the first few weeks is critical, as 5%-50% of OSA patients worldwide either reject or discontinue CPAP within the first week. 2
• Contact with healthcare providers (clinic visits or specialist nurse home visits) improves CPAP adherence. 2