Work of Breathing as a Predictor of Failure to Wean from Mechanical Ventilationin Patients with Severe Chronic Obstructive Pulmonary Disease

摘要

For the vast majority of patients who require mechanical ventilation, withdrawalof ventilatory support and extubation is straightforward and easily accomplished. However, those patients who have required prolonged ventilatory support and especially those with severe baseline pulmonary disease can present a particular problem. It is not always clinically evident when the patient is ready to be removed from ventilatory support. Extubation before the patient is prepared to support his own ventilatory demands can result in respiratory failure, and the requirement for reintubation and placement back on the ventilator. Reintubation, especially under urgent circumstances, is not without risks, such as aspiration and hemodynamic instability. The fatigue and stress that the patient develops while experiencing respiratory failure can also set back his clinical course significantly. Whereas a few more days of exercise prior to the initial extubation might have ensured success, the patient might now require days to weeks to again be ready for extubation. Conversely, the conservative approach might prolong the weaning process longer than is required, delay extubation and increase the chance for nosocomial complications, such as pneumonia.