One of the most frequent complications associated with endotracheal intubation itself in intensive care units is unplanned extubation, which represents a potentially serious complication given that many patients may need reintubation while in poor condition. This scenario may account for an increase in morbidity and even in mortality. To be able to compare the rates of unplanned extubation in clinical practice, unplanned extubation should be expressed as incidence density of days at risk. Also, this complication (unplanned extubation and reintubation rates) may be used as a marker of quality of weaning care in intensive care units.