Invasive Mechanical Ventilation for Patients Failing Noninvasive Ventilation

Immediate Action: Prepare for Intubation

The World Health Organization recommends that patients receiving BiPAP should be supervised by experienced clinicians capable of performing endotracheal intubation if the patient fails to improve or rapidly deteriorates 1
Delayed intubation in patients failing noninvasive ventilation is associated with increased mortality, emphasizing the importance of early recognition of failure 2

Once intubated, immediately implement lung-protective ventilation to minimize ventilator-induced lung injury and reduce mortality, with initial settings including a tidal volume of 6 mL/kg predicted body weight 1, 2, 3
Target plateau pressure should be <30 cmH2O, ideally <28 cmH2O, to reduce the risk of lung injury 1, 2, 3
PEEP titration should be guided by FiO2 requirements to achieve SpO2 >90% using the ARDSnet protocol 1, 3
Permissive hypercapnia is allowed, with PaCO2 permitted to rise while maintaining arterial pH >7.20 1, 2, 3

Consider early prone ventilation if PaO2/FiO2 <150 despite ventilator optimization, as it improves oxygenation in approximately 65% of ARDS patients 1, 2, 3
Prone positioning should last 12-16 hours daily 2
Consider ECMO for refractory hypoxemia despite lung-protective ventilation if extracorporeal life support is available 1, 3

The European Society of Intensive Care Medicine advises against delaying intubation in patients failing noninvasive ventilation, as this increases mortality risk 2
Never use tidal volumes >8 mL/kg predicted body weight, even if hypercapnia develops, as this increases mortality 2
When permitting hypercapnia, ensure arterial pH remains >7.20, and consider adjusting ventilator settings or treating the underlying metabolic component if pH falls below this threshold 2

Recognize BiPAP failure by assessing deterioration in arterial blood gases after 1-2 hours of optimal BiPAP settings, deteriorating conscious level, development of complications, persistent or worsening hypoxemia despite high FiO2, and patient intolerance or failure to synchronize with ventilator 4
If there is no improvement in PaCO2 and pH after 1-2 hours on optimal settings, NIV should be discontinued and invasive ventilation considered 4

The American Thoracic Society recommends that patients with persistent or worsening hypoxemia despite optimization of BiPAP settings and high FiO2 should be considered for intubation, as delayed intubation is associated with increased mortality, and no improvement in arterial blood gases (pH and PaCO2) after 1-2 hours on optimal settings is a key indicator of BiPAP failure 5
The Society of Critical Care Medicine suggests positioning the patient in semi-Fowler position (head and torso inclined) during intubation to improve first-pass success, continuing preoxygenation with NIPPV (BiPAP) until the moment of intubation, administering a sedative-hypnotic induction agent when using a neuromuscular blocking agent, and using a neuromuscular blocking agent (rocuronium or succinylcholine) when intubating with a sedative-hypnotic 6

The American College of Critical Care Medicine recommends targeting arterial O2 saturation of 92-97% by manipulating ventilator FiO2, avoiding early hyperoxia (PaO2 >300 mmHg) which is associated with mortality and poor neurological outcomes, targeting PaCO2 between 35-45 mmHg while avoiding a rapid drop in PaCO2 (>20 mmHg), and maintaining PEEP >10 cmH2O to maintain alveolar inflation and prevent pulmonary edema and atelectasis 7