IPAP and EPAP Settings on Ventilator
For adult patients requiring non-invasive ventilation, start with IPAP 8 cm H₂O and EPAP 4 cm H₂O, then titrate IPAP upward in 1-2 cm H₂O increments every 5 minutes based on tidal volume (target 6-8 mL/kg), PCO₂ reduction, and elimination of obstructive events, with maximum IPAP of 30 cm H₂O. 1
Initial Settings
Starting Pressures
- EPAP: 4 cm H₂O (minimum available on most devices) 1, 2, 1
- IPAP: 8 cm H₂O (providing minimum pressure support of 4 cm H₂O) 1, 2, 1
- Pressure Support (PS): 4 cm H₂O minimum (IPAP minus EPAP) 1
Maximum Limits
- IPAP maximum: 30 cm H₂O for patients ≥12 years 1
- IPAP maximum: 20 cm H₂O for patients <12 years 1
- Maximum PS: 20 cm H₂O 1
- Maximum IPAP-EPAP differential: 10 cm H₂O for OSA 2
Titration Algorithm
For Obstructive Events (Apneas, Hypopneas, RERAs, Snoring)
Increase IPAP and/or EPAP by ≥1 cm H₂O every 5 minutes until events are eliminated 1. For apneas specifically, increase both IPAP and EPAP together 2.
For Hypoventilation/Low Tidal Volume
Increase PS (IPAP) every 5 minutes if: 1
- Tidal volume <6-8 mL/kg ideal body weight
- PCO₂ remains ≥10 mmHg above goal for ≥10 minutes (goal: ≤awake PCO₂)
- SpO₂ <90% for ≥5 minutes AND tidal volume is low
- Respiratory muscle rest not achieved after ≥10 minutes
Incremental changes: 1-2 cm H₂O per adjustment (maximum 2 cm H₂O to avoid over-titration) 1
For Chronic Alveolar Hypoventilation
Use spontaneous-timed (ST) mode with backup rate for: 1
- Central hypoventilation
- Significant central apneas
- Inappropriately low respiratory rate
- Muscle weakness preventing reliable triggering
Backup rate settings: 1
- Start at spontaneous sleeping rate (minimum 10 bpm)
- Increase by 1-2 bpm every 10 minutes if goals not met
- IPAP time: 30-40% of cycle time (60/respiratory rate)
Special Considerations
Patient Comfort
If patient awakens complaining pressure is too high, decrease to comfortable level allowing return to sleep 1. Adjust rise time (100-400 ms for obstructive disease; 300-600 ms for restrictive disease) for comfort 1.
Supplemental Oxygen
Add oxygen if: 1
- Awake SpO₂ <88%, OR
- SpO₂ remains <90% for ≥5 minutes after optimizing PS and respiratory rate
- Start at 1 L/min, increase by 1 L/min every 5 minutes
- Target SpO₂ >90% (some guidelines suggest 92-96%) 3
CPAP vs BiPAP Decision
Switch from CPAP to BiPAP if: 2
- Patient intolerant of high CPAP pressures, OR
- Continued obstructive events at CPAP 15 cm H₂O
For hypoxemic respiratory failure, CPAP is first-line; BiPAP is reserved for type 2 respiratory failure (e.g., COPD with hypercapnia) 3.
Common Pitfalls
Avoid these errors:
- Starting with insufficient PS (<4 cm H₂O) - won't provide adequate ventilatory support 1
- Increasing pressures too rapidly (>2 cm H₂O increments) - risks over-titration 1
- Setting PEEP above intrinsic PEEP in COPD - can worsen hyperinflation 4
- Failing to use backup rate in neuromuscular disease - leads to inadequate ventilation 1
- Not monitoring for mask leak - significantly reduces delivered tidal volume 1
Monitor closely: Reassess within 1-2 hours of NIV initiation to prevent delayed intubation 3. Watch for treatment-emergent central apneas at high pressures - may require IPAP reduction or backup rate 2.