ABSTRACT
Ventilatory Support. Willingness to institute mechanical ventilation should be di rectly proportional to the risk of deterioration without support and inversely proportional to the anticipated difficulty of eventual weaning. Noninvasive ventilation offers an attractive option for many patients with mild to moderate disease and rapidly reversible etiologies for ventilatory failure (see Chap. 25). To reverse fatigue, a substantial fraction of the imposed workload must be relieved. Support can be assumed adequate if breathing is comfortable. Physiological evidence of subnormal performance can be detected in the laboratory setting for 12-24 h after an acutely fatiguing load has been briefly applied (< 30 mins). Therefore, patients should not be stressed to the point of fatigue, and a rest period of at least 12 h seems appropriate after an episode of acute decompensation.
