Initial Settings for Non-Invasive Ventilation (NIV) Pressure Control
For NIV pressure control mode, the recommended initial settings are IPAP of 8-10 cm H₂O and EPAP of 4-5 cm H₂O, with a minimum pressure support of 4 cm H₂O and a backup respiratory rate of 12-15 breaths/minute. 1
Mode Selection and Basic Settings
Bi-level Pressure Support Mode
- Initial IPAP (Inspiratory Positive Airway Pressure): 8-10 cm H₂O
- Initial EPAP (Expiratory Positive Airway Pressure): 4-5 cm H₂O
- Minimum pressure support: 4 cm H₂O (difference between IPAP and EPAP)
- Maximum pressure support: Should not exceed 20 cm H₂O 1
- Maximum IPAP: 30 cm H₂O for adults (≥12 years), 20 cm H₂O for children (<12 years) 1
- Backup respiratory rate: 12-15 breaths/minute
Flow and Trigger Settings
- Flow trigger sensitivity: Set to detect patient's inspiratory effort with minimal work
- Rise time: Start with medium setting and adjust based on patient comfort
- Inspiratory time: 0.8-1.2 seconds initially, or 25-33% of respiratory cycle
- Flow termination criteria: 25-30% of peak inspiratory flow
Titration Algorithm
Start with baseline settings (IPAP 8-10 cm H₂O, EPAP 4-5 cm H₂O)
Adjust for obstructive events:
- For obstructive apneas: Increase EPAP by 1-2 cm H₂O every 5 minutes 1
- For hypopneas/snoring: Increase EPAP by 1 cm H₂O every 5 minutes
- Maintain pressure support by increasing IPAP accordingly
Adjust for hypoventilation:
- If tidal volume is inadequate: Increase pressure support by 1-2 cm H₂O every 5 minutes 1
- If persistent hypercapnia: Increase IPAP while maintaining EPAP
Adjust for patient comfort:
- If patient reports difficulty exhaling: Decrease IPAP or increase rise time
- If air hunger persists: Increase pressure support
Oxygen Supplementation
- Add supplemental oxygen to maintain SpO₂ targets:
Monitoring and Assessment
- Evaluate patient response within 1-2 hours of initiating NIV 1
- Monitor:
- Respiratory rate and pattern
- SpO₂ continuously
- Arterial or venous blood gases within 1-2 hours
- Patient-ventilator synchrony
- Air leaks
Common Pitfalls and Solutions
Interface Issues
- Excessive leakage: Ensure proper mask fit; consider different interface size/type
- Pressure ulcers: Use protective dressings on pressure points; rotate interfaces if needed
- Claustrophobia: Start with lower pressures; consider nasal mask if tolerated 3
Ventilation Problems
- Asynchrony: Adjust trigger sensitivity and rise time; consider switching to timed mode if persistent
- Inadequate ventilation: Increase pressure support; check for leaks
- Rebreathing: Ensure EPAP is adequate (minimum 4-5 cm H₂O) to flush CO₂ from circuit 1
Patient Tolerance
- Discomfort: Start with lower pressures and gradually increase
- Aerophagia: Reduce pressure if possible; proper positioning (semi-recumbent)
- Dry mouth/nasal congestion: Add heated humidification 1
Special Considerations
COPD Patients
- Higher EPAP (5-6 cm H₂O) may be needed to overcome intrinsic PEEP
- Target pressure support to achieve tidal volumes of 6-8 ml/kg
- Monitor for worsening hypercapnia due to excessive pressure
Neuromuscular Disease
- Consider timed/assist-control mode if respiratory effort is insufficient to trigger breaths 1
- Higher backup rate may be necessary
- Monitor closely for upper airway collapse during sleep
Cardiogenic Pulmonary Edema
- Higher initial EPAP (8-10 cm H₂O) may be beneficial
- CPAP mode may be equally effective as bi-level in this condition 4
- Target higher SpO₂ (94-96%) if no risk of hypercapnia
By following these initial settings and adjustment algorithms, clinicians can optimize NIV delivery to improve patient outcomes while minimizing complications related to inappropriate ventilator settings.