Weaning of the Patient with ARDS

Assessment of weaning readiness The ability to separate successfully from mechanical ventilation is dependent upon a host of physiologic factors (Table 1). Central ventilatory drive must be adequate; the patient must be able to maintain a patent airway, if extubation or decannulation is contemplated; and the patient must be able to cough and adequately clear secretions. Airway resistance must be adequately low; airway edema or obstruction can preclude extubation. The work of breathing must be adequately low; decreased lung compliance, increased airway resistance, and hyperinflation impose an increased load upon respiratory muscles. The respiratory muscles themselves must possess sufficient strength and endurance. Even with normal respiratory muscle function, however, abnormal chest wall mechanics, such as severe hyperinflation, abdominal distention, or kyphoscoliosis can place respiratory muscles at a mechanical disadvantage, resulting in fatigue and respiratory failure.