Ventilator Management in Acute Lung Injury/Acute Respiratory Distress Syndrome (ALI/ARDS)

Introduction to Lung-Protective Ventilation

The American Thoracic Society recommends lung-protective ventilation with low tidal volumes (approximately 6 mL/kg ideal body weight) and permissive hypercapnia for mechanically ventilated patients with ALI/ARDS who have high inspiratory pressures or are at risk for barotrauma/volutrauma, as this approach reduces mortality and prevents ventilator-induced lung injury 1, 2
The Society of Critical Care Medicine suggests that reducing tidal volume and minute ventilation to prevent alveolar overdistension and perpetuation of lung injury is a key component of lung-protective ventilation 1, 2
The use of lung-protective ventilation with low tidal volumes has been shown to be safe and effective at reducing mortality without adverse consequences, according to the American College of Chest Physicians 1, 2

Maintaining end-inspiratory plateau pressures at levels less than 30 cmH₂O is recommended by the American Association for Respiratory Care to prevent lung injury 1, 2
Allowing PaCO₂ to rise while maintaining arterial pH above 7.20 is a key aspect of permissive hypercapnia, as suggested by the European Society of Intensive Care Medicine 1, 2
The American College of Cardiology recommends considering prone positioning if PaO₂/FiO₂ ratio is ≤100 mmHg, as this improves oxygenation in approximately 65% of ARDS patients 1, 2, 5

If BiPAP fails (persistent hypoxemia despite optimization), the American Thoracic Society suggests proceeding to endotracheal intubation and mechanical ventilation with lung-protective settings 1, 2
The Society of Critical Care Medicine recommends monitoring for BiPAP failure closely, as delayed intubation is associated with increased mortality 4
The European Society of Intensive Care Medicine advises against delaying intubation in patients failing noninvasive ventilation, as this increases mortality risk 4

The American Association for Respiratory Care warns against using high tidal volumes (>8 mL/kg predicted body weight) even if hypercapnia develops, as this increases mortality 1, 2, 4
The American College of Chest Physicians recommends against attempting to normalize blood gases at the expense of lung-protective ventilation parameters 1, 2
The American Thoracic Society suggests ensuring arterial pH remains >7.20 when permitting hypercapnia 1, 2