What is the recommended initial pressure support setting for patients on BiPAP (Bilevel Positive Airway Pressure)?

BiPAP Pressure Support Settings

Initial Pressure Settings

Start BiPAP with an IPAP of 8 cm H₂O and EPAP of 4 cm H₂O for all patients, both adults and children. 1, 2 This represents the consensus recommendation from the American Academy of Sleep Medicine and provides a standardized starting point that balances efficacy with patient tolerance.

Pressure Support Calculation

• The initial pressure support (PS) is 4 cm H₂O (calculated as IPAP minus EPAP: 8 - 4 = 4 cm H₂O) 2
• This 4 cm H₂O differential represents the minimum recommended pressure support that should be maintained throughout titration 1, 2

Pressure Support Range

• Minimum PS: 4 cm H₂O (the difference between minimum IPAP and EPAP) 1, 2
• Maximum PS: 10 cm H₂O (the maximum allowable IPAP-EPAP differential) 1, 2
• For chronic alveolar hypoventilation syndromes specifically, the maximum PS can extend to 20 cm H₂O 1

Titration Algorithm

When to Increase Pressure Support

Increase IPAP alone (thereby increasing PS) in the following scenarios:

• ≥3 hypopneas observed in patients ≥12 years (or ≥1 hypopnea in patients <12 years) 1
• ≥5 RERAs (respiratory effort-related arousals) in patients ≥12 years (or ≥3 RERAs in patients <12 years) 1
• ≥3 minutes of loud snoring in patients ≥12 years (or ≥1 minute in patients <12 years) 1
• Low tidal volume (<6-8 mL/kg) in patients with chronic alveolar hypoventilation 1
• Elevated PCO₂ remaining ≥10 mm Hg above goal for ≥10 minutes 1

Increase both IPAP and EPAP together (maintaining the same PS) when:

• ≥2 obstructive apneas are observed in patients ≥12 years (or ≥1 apnea in patients <12 years) 1

Titration Increments and Timing

• Increase pressures by at least 1 cm H₂O per adjustment 1, 2
• Wait at least 5 minutes between pressure changes to assess response 1, 2
• Continue titration until respiratory events are eliminated for ≥30 minutes or maximum pressures are reached 1

Maximum Pressure Limits

Age-Based IPAP Maximums

• Patients <12 years: Maximum IPAP of 20 cm H₂O 1, 2
• Patients ≥12 years: Maximum IPAP of 30 cm H₂O 1, 2

Pressure Support Constraints

• Never exceed 10 cm H₂O differential between IPAP and EPAP in obstructive sleep apnea patients 1, 2
• For chronic alveolar hypoventilation, PS up to 20 cm H₂O may be used if needed 1

Special Considerations

Patients with Elevated BMI

• Consider starting with higher initial pressures than the standard 8/4 cm H₂O, though specific values are not defined by guidelines 1, 2
• The exact starting pressures should be determined based on body habitus 2

Patient Intolerance

• If the patient awakens complaining pressure is too high, restart at a lower pressure that the patient reports is comfortable enough to allow return to sleep 1, 2
• This is a consensus recommendation prioritizing adherence over aggressive titration 1

Treatment-Emergent Central Apneas

• Decrease IPAP (thereby decreasing PS) if central apneas develop during titration 1
• Alternatively, switch to spontaneous-timed (ST) mode with backup rate 1

Mode Selection

Obstructive Sleep Apnea

• Use spontaneous (S) mode where the patient triggers all breaths 2

Poor Respiratory Drive

• Use spontaneous-timed (ST) mode with backup rate for patients with central hypoventilation, significant central apneas, or muscle weakness preventing reliable triggering 1, 2
• Set backup rate at 10-12 breaths/minute (equal to or slightly less than spontaneous sleeping respiratory rate, minimum 10 bpm) 1
• Configure inspiratory time to provide 30-40% of cycle time 1

Common Pitfalls

Pressure Exploration

• Do not increase IPAP more than 5 cm H₂O above the pressure that eliminates respiratory events 1
• While exploration can reduce residual upper airway resistance, excessive pressure increases reduce tolerance 1

Acute Care Settings

• In emergency department or acute respiratory distress scenarios, research suggests starting at 8/3 cm H₂O and titrating to 12/7 cm H₂O based on tolerance 3
• Evaluate response within 1-2 hours of initiating BiPAP in acute settings 2, 4
• Inability to maintain SpO₂ >90% despite FiO₂ escalation indicates BiPAP failure requiring intubation 2, 4

COPD Patients

• Be aware that BiPAP may increase work of breathing in COPD patients compared to pressure support ventilation, particularly during the low-pressure phase 5
• Ensure adequate expiratory time to prevent air trapping 4