How to manage double triggering during a Bilevel Positive Airway Pressure (BPAP) titration study?

Managing Double Triggering During BPAP Titration Study

When double triggering occurs during BPAP titration, decrease IPAP or switch to spontaneous-timed (ST) mode with a backup rate, especially if treatment-emergent central apneas are observed.

Understanding Double Triggering in BPAP

Double triggering is a form of patient-ventilator asynchrony that can occur during BPAP titration. It happens when two consecutive breaths are delivered with minimal time between them, potentially causing:

• Alveolar overdistention
• Generation of intrinsic PEEP
• Patient discomfort
• Compromised treatment efficacy

Types of Double Triggering

Double triggering can be classified into three types based on what triggers the first breath 1:

1. Patient-triggered double triggering (DT-P) - First breath is initiated by patient effort
2. Auto-triggered double triggering (DT-A) - First breath occurs without patient effort
3. Ventilator-triggered double triggering (DT-V) - First breath occurs at the ventilator's set cycle time

Management Algorithm for Double Triggering

Step 1: Identify the Cause

• If treatment-emergent central apneas are observed:

  • This may indicate complex sleep apnea
  • Consider decreasing IPAP or switching to ST mode with backup rate 2

• If patient is breathing too rapidly:

  • Check for transitions between NREM and REM sleep, as tachypnea can occur during these transitions 3
  • Evaluate for underlying ventilatory instability

Step 2: Adjust BPAP Settings

• Decrease IPAP if double triggering is associated with central apneas 2
• Adjust IPAP-EPAP differential (maintain between 4-10 cm H₂O) 2
• Consider switching to ST mode with an appropriate backup rate 2
• Ensure proper mask fit to eliminate unintentional leaks 2

Step 3: Reassess After Adjustments

• Monitor for at least 15 minutes after each adjustment
• Aim for optimal titration (RDI <5/hour for at least 15 minutes) 4
• Ensure SpO₂ remains above 90% at the selected pressure 2

Special Considerations

Pressure Exploration

• If double triggering persists despite adjustments, do not increase IPAP exploration beyond 5 cm H₂O above the pressure that controls respiratory events 2

Patient Comfort

• If patient awakens and complains of pressure discomfort, restart at a lower pressure that allows return to sleep 2
• Document patient tolerance and comfort with each setting

Titration Quality Assessment

• An optimal titration should reduce RDI to <5/hour for at least 15 minutes 4
• Include supine REM sleep at the selected pressure that is not continually interrupted by arousals 2
• Ensure minimum SpO₂ above 90% at the selected pressure 4

Common Pitfalls to Avoid

• Ignoring mask leaks - Significant unintentional leaks can trigger asynchrony and should be addressed immediately 4
• Excessive pressure increases - May worsen patient-ventilator synchrony
• Overlooking central apneas - Treatment-emergent central apneas require specific management approaches
• Relying solely on patient reports - Patients often underreport problems 4

When to Consider a Repeat Study

If double triggering cannot be resolved during the initial titration, consider a repeat study if:

• The initial titration fails to achieve optimal, good, or adequate grade 4
• Less than 3 hours of sleep was recorded during the initial titration 4
• Patient continues to have symptoms despite seemingly appropriate settings 4

By following this algorithm, clinicians can effectively manage double triggering during BPAP titration, improving patient comfort and treatment efficacy while minimizing potential complications.