What are the recommended ventilator settings for type 2 respiratory failure?

Ventilator Settings for Type 2 Respiratory Failure

For patients with type 2 respiratory failure, bilevel positive airway pressure (BiPAP) should be used with settings tailored to achieve pH >7.20, PaCO2 normalization, and SpO2 88-92%. 1

Initial Assessment and Mode Selection

• BiPAP is the preferred ventilation mode for type 2 respiratory failure (e.g., in COPD), while CPAP is more appropriate for hypoxemic respiratory failure 1
• NIV should be started when pH <7.35, PaCO2 ≥6.5 kPa (48.8 mmHg), and respiratory rate >23 breaths/min persists after one hour of optimal medical therapy 1
• For patients with PaCO2 between 6.0-6.5 kPa (45-48.8 mmHg), NIV should be considered but is not mandatory 1
• For patients with poor respiratory drive, use NIV with CPAP plus additional pressure support and a backup rate (BiPAP) 1

Specific Ventilator Settings

Non-Invasive Ventilation Settings

• IPAP (Inspiratory Positive Airway Pressure): Start at 10-12 cmH2O, titrate up based on patient tolerance and response 1
• EPAP (Expiratory Positive Airway Pressure): Start at 5 cmH2O to overcome intrinsic PEEP and facilitate triggering 1
• Backup Rate: Set to ensure minimum ventilation in patients with poor respiratory drive 1
• FiO2: Titrate to maintain target SpO2 of 88-92% in type 2 respiratory failure 1

Invasive Mechanical Ventilation Settings (if NIV fails)

• Tidal Volume: 6-8 ml/kg predicted body weight 2, 3
• PEEP: 5-8 cmH2O, adjusted based on underlying condition 1, 2
• Respiratory Rate: 10-15 breaths per minute initially, adjusted to maintain pH >7.20 2
• Plateau Pressure: Maintain <30 cmH2O to prevent barotrauma 2, 3
• FiO2: Titrate to maintain SpO2 88-92% 1

Monitoring and Adjustments

• Closely monitor patient's condition within 1-2 hours after initiating NIV to prevent delay in intubation if needed 1
• Arterial blood gases should be checked at 1 hour and 4 hours after initiating ventilation 1
• Target pH >7.20 and improvement in work of breathing 1
• Consider AVAPS (Average Volume-Assured Pressure Support) mode for more rapid improvement in pH and PaCO2 in COPD patients with type 2 respiratory failure 4
• Monitor for patient-ventilator asynchrony and adjust settings accordingly 1

Special Considerations

• In patients with COPD, setting PEEP greater than intrinsic PEEP can be harmful 1
• Controlled oxygen therapy should be used to achieve a target saturation of 88-92% in ALL causes of AHRF 1
• Consider sedation carefully in invasively ventilated patients to avoid prolonged ventilation and ICU stay 1
• Ventilator asynchrony should be considered in all agitated patients and settings should be reviewed regularly as patients recover 1

When to Escalate Care

• Consider intubation if no improvement or worsening in clinical status within 1-2 hours of NIV 1
• Failure criteria: worsening respiratory acidosis, increasing oxygen requirements, decreased level of consciousness, inability to clear secretions 1
• Early intubation should be considered in patients with severe acidosis (pH <7.25) or severe hypoxemia despite NIV 1

Common Pitfalls to Avoid

• Delaying intubation when NIV is failing can increase mortality 1
• Using excessive PEEP in obstructive diseases can worsen air trapping 1
• Setting FiO2 too high (>96%) can worsen hypercapnia in type 2 respiratory failure 1
• Inadequate monitoring of arterial blood gases can lead to missed opportunities for ventilator adjustments 1