Reference — Mechanical Ventilation
NIV Initial Settings
Where to start bilevel and CPAP, how to titrate when the patient is under- or over-supported, and the failure signs that mean NIV is not working — before it delays a needed intubation.
Written by Apex Respiratory Editorial Team
Educational use only. This material supports respiratory therapy education and exam review. It is not medical advice and is not a substitute for clinical judgment, institutional protocols, or physician orders. Always follow facility policies and current provider orders, and verify calculations independently before clinical use.
Overview
These are conservative starting points for an adult; titrate to the patient’s comfort, tidal volume, and gas exchange. Bilevel (BiPAP) separates an inspiratory and expiratory pressure to support ventilation and oxygenation independently; CPAP delivers one continuous pressure. Start low, explain the mask, and reassess early.
Bilevel (BiPAP) Quick-Start
| Setting | Initial | Notes |
|---|---|---|
| IPAP | 8 – 12 cmH₂O | Titrate up by 2 to improve ventilation / tidal volume |
| EPAP | 4 – 5 cmH₂O | Titrate to improve oxygenation and maintain upper-airway patency |
| Pressure support | IPAP − EPAP | The driving pressure delivered to each breath |
| Backup rate | Per device / protocol | Ensures a minimum rate in spontaneous-timed modes |
| FiO₂ | Titrate to target SpO₂ | 88 – 92% in chronic CO₂ retainers; 92 – 96% otherwise |
CPAP Quick-Start
| Scenario | Pressure |
|---|---|
| General starting range | 5 – 10 cmH₂O |
| Cardiogenic pulmonary edema | Commonly 8 – 12 cmH₂O |
Titration Guide
| Problem | Adjustment |
|---|---|
| High CO₂ / inadequate ventilation | ↑ IPAP in 2 cmH₂O steps (widens pressure support and raises tidal volume) |
| Low SpO₂ / hypoxemia | ↑ EPAP and/or ↑ FiO₂ — raising EPAP without IPAP narrows pressure support, so raise IPAP to keep it constant |
| Patient intolerance | Refit the mask, use the ramp feature, and coach the patient; consider a different interface |
Monitoring & Skin Care
- Reassess within 1 – 2 hours with a blood gas. Improving pH and respiratory rate predict success; a flat or worsening trend predicts failure.
- Watch for failure signs. Worsening pH or rising rate, persistent intolerance, copious secretions, declining mental status, or hemodynamic instability all signal escalation — never let NIV delay a needed intubation.
- Protect the skin. Guard the nasal bridge (consider a barrier dressing), check mask fit and strap tension, watch for pressure injury and gastric insufflation, and humidify to keep secretions manageable.
Related Resources
Sources
- Rochwerg B, Brochard L, Elliott MW, et al. Official ERS/ATS clinical practice guidelines: noninvasive ventilation for acute respiratory failure. Eur Respir J. 2017;50(2):1602426.
- Kacmarek RM, Stoller JK, Heuer AJ. Egan's Fundamentals of Respiratory Care. 12th ed. Elsevier; 2021. Noninvasive ventilation chapter.