Proceed Immediately to Endotracheal Intubation
A patient on BiPAP with high FiO2 who is not improving should be intubated without delay, as delayed intubation in patients failing noninvasive ventilation is associated with increased mortality. 1
Recognize BiPAP Failure Early
Monitor for these specific indicators of BiPAP failure after 1-2 hours of optimal settings:
- No improvement or worsening of arterial blood gases (pH and PaCO2) after 1-2 hours indicates NIV should be discontinued and invasive ventilation initiated 2, 1
- Persistent or worsening hypoxemia despite high FiO2 1
- Deteriorating conscious level or abnormal mental status 2, 1
- Hemodynamic instability or multi-organ failure 2
- Patient intolerance or failure to synchronize with the ventilator 1
The World Health Organization emphasizes that patients on BiPAP must be supervised by experienced clinicians capable of performing endotracheal intubation if the patient fails to improve or rapidly deteriorates 1. The European Society of Intensive Care Medicine specifically advises against delaying intubation in patients failing noninvasive ventilation, as this increases mortality risk 1, 3.
Immediate Post-Intubation Management
Once intubated, implement lung-protective ventilation immediately to minimize ventilator-induced lung injury:
- Set tidal volume at 6 mL/kg predicted body weight (never exceed 8 mL/kg even if hypercapnia develops, as higher volumes increase mortality) 1, 3
- Target plateau pressure <30 cmH2O, ideally <28 cmH2O to reduce risk of lung injury 1, 3
- Titrate PEEP guided by FiO2 requirements using the ARDSnet protocol to achieve SpO2 >90% 1
- Allow permissive hypercapnia with PaCO2 permitted to rise while maintaining arterial pH >7.20 1, 3
Advanced Interventions if No Improvement After 12 Hours
If the patient remains hypoxemic despite optimized mechanical ventilation:
- Consider early prone positioning if PaO2/FiO2 <150, as this improves oxygenation in approximately 65% of ARDS patients 1, 3
- Prone positioning should last 12-16 hours daily 1
- Consider ECMO for refractory hypoxemia despite lung-protective ventilation if extracorporeal life support is available 1
Critical Pitfalls to Avoid
- Never delay intubation beyond 1-2 hours if there is no improvement on optimal BiPAP settings, as delayed intubation worsens outcomes and puts medical personnel at risk during emergency intubation 2, 1
- Do not use tidal volumes >8 mL/kg predicted body weight even if hypercapnia develops, as this increases mortality 1, 3
- Do not attempt to normalize blood gases at the expense of lung-protective ventilation parameters 3
- When permitting hypercapnia, ensure arterial pH remains >7.20 1, 3
Special Considerations for Obese Patients
If the patient has obesity hypoventilation syndrome:
- High EPAP settings (10-15 cmH2O range) may be required due to upper airway obstruction 2
- IPAP >30 may be needed due to high impedance to inflation 2
- Fluid overload commonly contributes to ventilatory failure and is easily underestimated (may exceed 20 L), requiring forced diuresis 2
- Placement in HDU/ICU is recommended due to greater risk of NIV failure and difficult intubation 2