Bilevel Positive Airway Pressure (BPAP) Ventilation

Last updated 25/12/15

Definition

• Common form of pressure-cycled Non-Invasive Ventilation (NIV) with different levels of airway pressure applied during inspiration and expiration

Features

• More beneficial in obstructive airways disease as less pressure on expiration reduces gas trapping and CO2 retention
• Inspiratory Positive Airway Pressure (IPAP) > Expiratory Positive Airway Pressure (EPAP)
• Equivelant to Pressure Support Ventilation (PSV) + PEEP in a mechanically ventilated patient
• Applied to a conscious spontaneously breathing patient
• IPAP applied and when reduced flow is sensed pressure is reduced to EPAP

Indications

• Hypercapnoeic patients not improving with supplemental oxygen
• Chronic Obstructive Pulmonary Disease (COPD)
• Asthma
• +/- Acute Pulmonary Oedema (APO): Continuous Positive Airway Pressure (CPAP) is preferred

Variables

• IPAP
• Commene at 8-10 cmH2O
• Cautious use >20 cmH2O
• Not to exceed 25 cmH2O
• Used to assist minute ventilation (RR x TV)
• Increases gas exchange by increasing volume of gas
• Titrate to establish adequate TV: 6ml/kg IBW
• If RR >25 or respiratory acidosis not improving after 15 minutes indicates inadequate minute volume to remove CO2
• Increase IPAP to achieve TV of 7ml/kg
• If still not improving after 15 minutes increase to 8ml/kg (maximum)
• EPAP
• Commance at (0)3-5 cmH2O
• Equivelant to PEEP (Positive End Expiratory Pressure)
• Used to reduce shunt (V/Q mismatch)
• Increases gas exchange by increasing airway involved in gas exchange
• FiO2
• 0.21 - 1.0 as required by blood gas and oxygen saturation

Procedure

• Setup for NIV
• COPD
• IPAP: 10-15 cmH2O
• EPAP: 3-7 cmH2O
• Asthma
• IPAP: 8 cmH2O
• EPAP: 0-3 cmH2O
• FiO2: 100%

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References

1. Khilnani G, Banga A. Noninvasive ventilation in patients with chronic obstructive pulmonary disease. Int J Chron Obstruct Pulmon Dis. 2008;3(3):351-357.