How do I operate a Bilevel Positive Airway Pressure (BiPAP) machine?

How to Operate a BiPAP Machine

BiPAP machines should be operated following a systematic approach that includes proper setup, interface selection, pressure adjustment, and monitoring to ensure optimal ventilatory support and patient comfort. 1, 2

Initial Setup

Interface Selection and Fitting

• Choose the appropriate interface (nasal mask, nasal pillows, or full-face/oronasal mask) based on patient comfort and breathing pattern
• Properly fit the mask to maximize comfort and minimize leaks
• Have several different types of interfaces available if the patient encounters problems 1
• Ensure the mask is snug but not too tight to prevent skin breakdown

Machine Connection

1. Connect the flexible hose between the BiPAP device and the interface
2. Ensure the exhalation port or valve is properly installed and functioning
3. Add a humidifier if needed for comfort (especially if patient complains of dryness) 2

Initial Settings

Standard BiPAP Settings

• IPAP (Inspiratory Positive Airway Pressure): Start at 8 cm H₂O 2
• EPAP (Expiratory Positive Airway Pressure): Start at 4 cm H₂O 2
• IPAP-EPAP differential: Maintain minimum of 4 cm H₂O 2
• Rise time: Start at approximately 200 ms (default) 1
  • Patients with obstructive airway disease often prefer shorter rise times (100-400 ms)
  • Patients with restrictive disease often prefer longer rise times (300-600 ms)

Mode Selection

• Spontaneous (S) mode: Patient determines respiratory rate and IPAP time
• Spontaneous-Timed (ST) mode: Provides backup rate to ensure minimum respiratory rate 1
  • Set backup rate equal to or slightly less than spontaneous sleeping respiratory rate (minimum 10 breaths/minute) 2
  • Use ST mode for patients with central hypoventilation, significant central apneas, low respiratory rate, or muscle weakness 2
• Timed (T) mode: Delivers IPAP/EPAP cycles at set respiratory rate with set inspiratory time 1

Pressure Adjustment and Titration

Pressure Adjustment Protocol

1. Start with initial settings (IPAP 8 cm H₂O, EPAP 4 cm H₂O)
2. Increase IPAP in 1-2 cm H₂O increments at intervals no shorter than 5 minutes 2
3. Increase EPAP in 1 cm H₂O increments as needed 2
4. Target SpO₂ of 90-96% 2
5. If patient complains pressure is too high, decrease to a comfortable level that allows return to sleep 1, 2

Addressing Common Issues

• Mask leak: Refit, adjust, or change mask type 1
• Mouth leak: Consider oronasal mask or chin strap 1
• Difficulty exhaling: Use pressure relief during EPAP (flexible PAP) 1
• Dryness or nasal congestion: Add heated humidification 2

Advanced Settings and Adjustments

Fine-Tuning for Patient Comfort

• Minimum IPAP duration: Increase if device cycles from IPAP to EPAP prematurely 1
• Maximum IPAP duration: Decrease if device cycles to EPAP too late 1
• Inspiratory time: Set between 30-40% of the cycle time 2
• Backup rate adjustment: Make in 1-2 breaths per minute increments every 10 minutes if goals not attained 2

Monitoring During Operation

• Monitor for unintentional leaks
• Ensure exhalation ports remain unobstructed (occlusion can worsen hypercapnia) 1
• For patients requiring nighttime ventilation, monitor oxygen saturation with pulse oximetry 1

Common Pitfalls to Avoid

1. Inadequate mask fit: Leads to excessive leaks and reduced effectiveness
2. Blocked exhalation port: Can cause rebreathing and worsen hypercapnia 1
3. Inappropriate pressure settings: Too high causes discomfort; too low fails to treat underlying condition
4. Using oxygen without ventilatory support: Not recommended for sleep-related hypoventilation 1
5. Ignoring patient comfort: Poor comfort leads to reduced adherence

Follow-up and Monitoring

• Schedule periodic reassessment appropriate to stage of disease 1
• Monitor for development of daytime hypoventilation, which may necessitate around-the-clock ventilation 1
• Regularly check device usage data and symptom improvement 2

By following these systematic steps, BiPAP therapy can be effectively administered to improve ventilation, reduce work of breathing, and enhance patient comfort and outcomes.