ABSTRACT
Ideally, mechanical ventilatory support is discontinued as soon as it is no longer required.
Unfortunately, identifying when this point is reached in the course of a patient’s illness
may be difficult. Failure to recognize that a patient is able to breathe spontaneously
results in excess ventilator days, increased hospital and ICU lengths of stay and costs,
added stress for the patient and family, and, of greatest importance, increased ventilator-
associated complications, notably ventilator-associated pneumonia. On the other hand,
premature discontinuation of support results in respiratory distress and the need for
reintubation. Failed extubation is associated with significant morbidity and mortality
(mortality as high as 40% in some series) (1-4). Although the marked morbidity and
mortality among patients failing extubation undoubtedly reflect the morbidity of the
underlying diseases causing the respiratory failure, reintubation itself is associated with
complications such as airway trauma and aspiration (5,6). Additionally, the interval of res-
piratory distress preceding reintubation may cause respiratory fatigue, which can further
delay ultimate weaning, as well as further deterioration in an already compromised
patient. For all these reasons, the ability to accurately determine the earliest time when
a patient is fully able to resume spontaneous ventilation is of great importance.
