How do you set up Bilevel Positive Airway Pressure (BiPAP) therapy for an adult patient with Chronic Obstructive Pulmonary Disease (COPD) or sleep apnea?

How to Set BiPAP

Start with IPAP 8 cm H₂O and EPAP 4 cm H₂O for all adult and pediatric patients, then titrate upward in 1 cm H₂O increments at 5-minute intervals until obstructive events are eliminated. 1, 2

Initial Pressure Settings

• Begin with IPAP of 8 cm H₂O and EPAP of 4 cm H₂O as the standard starting point for both adults and children 1, 2
• For obese patients (elevated BMI), consider starting with higher initial pressures than these baseline values, though the exact increment should be based on body habitus 1, 2
• Always maintain a minimum pressure differential of 4 cm H₂O between IPAP and EPAP 1, 2
• Never exceed a maximum pressure differential of 10 cm H₂O 1, 2

Maximum Pressure Limits

• For patients under 12 years: maximum IPAP is 20 cm H₂O 1, 2
• For patients 12 years and older: maximum IPAP is 30 cm H₂O 1, 2

Titration Protocol During Sleep Studies

Increase IPAP and/or EPAP by at least 1 cm H₂O increments with intervals no shorter than 5 minutes until all obstructive respiratory events are eliminated. 1, 2

The titration hierarchy follows this order:

• Increase both IPAP and EPAP together if ≥2 obstructive apneas occur (adults ≥12 years) or ≥1 apnea (children <12 years) 1
• Increase IPAP alone if ≥3 hypopneas occur (adults ≥12 years) or ≥1 hypopnea (children <12 years) 1
• Increase IPAP alone if ≥5 RERAs occur (adults ≥12 years) or ≥3 RERAs (children <12 years) 1
• Increase IPAP alone if ≥3 minutes of loud snoring occur (adults ≥12 years) or ≥1 minute (children <12 years) 1

Continue titration until achieving at least 30 minutes without any breathing events 1

When to Switch from CPAP to BiPAP

Switch to BiPAP when the patient cannot tolerate CPAP pressures or when obstructive events persist at 15 cm H₂O of CPAP. 2, 3

Specific indications include:

• Patient discomfort or intolerance at high CPAP pressures (even before reaching 15 cm H₂O) 2
• Persistent obstructive respiratory events at CPAP of 15 cm H₂O 2
• Concomitant hypoventilation syndromes (COPD, neuromuscular disease, obesity hypoventilation syndrome) 3
• Type 2 respiratory failure with elevated PaCO₂ 3

Mode Selection

• For obstructive sleep apnea: Use spontaneous mode (S mode) where the patient triggers all breaths 2, 4
• For poor respiratory drive or central events: Use spontaneous-timed mode (ST mode) with a backup respiratory rate 2, 4
• If treatment-emergent central apneas develop, consider decreasing IPAP or switching to ST mode with backup rate 1

Critical Pre-Titration Steps

Before initiating BiPAP titration, ensure:

• Adequate patient education about BiPAP therapy 2
• Hands-on demonstration of the device 2
• Careful mask fitting to minimize leaks 2, 3
• Acclimatization period at low pressures 2

Proper mask fitting is essential—air leaks reduce treatment effectiveness and increase the likelihood of aerophagia regardless of pressure settings. 2, 3

Managing Patient Discomfort During Titration

If the patient awakens complaining that pressure is too high, immediately restart at a lower pressure that allows the patient to return to sleep comfortably. 1, 2

Do not persist with uncomfortable pressures, as this leads to poor long-term adherence 2

Pressure Exploration

Once control of respiratory abnormalities is achieved, "exploration" of IPAP above the therapeutic pressure should not exceed 5 cm H₂O 1

Special Considerations for Acute Care Settings

For patients with acute respiratory failure:

• Evaluate response within 1-2 hours of initiating BiPAP 2, 3
• If unable to maintain SpO₂ >90% despite escalating FiO₂, this indicates BiPAP failure requiring intubation 2
• Target SpO₂ of 90-96% during titration, with some guidelines recommending ≥92% 3
• Monitor blood gases for improvement in PaCO₂ and PaO₂ in hypercapnic patients 3

Common Pitfalls to Avoid

• Inadequate EPAP (<3-4 cm H₂O): This allows CO₂ rebreathing in the circuit, negating ventilatory benefits 4
• Excessive mask leak: Reduces effective pressure delivery and tidal volume, impairing treatment 4
• Overly aggressive titration: Attempting to normalize CO₂ too rapidly can trigger glottic closure and patient-ventilator asynchrony 4
• Using domiciliary CPAP machines for acute respiratory failure: These devices cannot maintain adequate pressure in patients with rapid respiratory rates and high minute ventilation 1