Comparison of International Consensus Conference guidelines and WIND classification for weaning from mechanical ventilation in Brazilian critically ill patients A retrospective cohort study

The knowledge of weaning ventilation period is fundamental to understand the causes and consequences of prolonged weaning. In 2007, an International Consensus Conference (ICC) defined a classification of weaning used worldwide. However, a new definition and classification of weaning (WIND) were suggested in 2017. The objective of this study was to compare the incidence and clinical relevance of weaning according to ICC and WIND classification in an intensive care unit (ICU) and establish which of the classifications fit better for severely ill patients. This study was a retrospective cohort study in an ICU in a tertiary University Hospital. Patient data, such as population characteristics, mechanical ventilation (MV) duration, weaning classification, mortality, SAPS 3, and death probability, were obtained from a medical records database of all patients, who were admitted to ICU between January 2016 and July 2017. Three hundred twenty-seven mechanically ventilated patients were analyzed. Using the ICC classification, 82% of the patients could not be classified, while 10%, 5%, and 3% were allocated in simple, difficult, and prolonged weaning, respectively. When WIND was used, 11%, 6%, 26%, and 57% of the patients were classified into short, difficult, prolonged, and no weaning groups, respectively. Patients without classification were sicker than those that could be classified by ICC. Using WIND, an increase in death probability, MV days, and tracheostomy rate was observed according to weaning difficult. Our results were able to find the clinical relevance of WIND classification, mainly in prolonged, no weaning, and severely ill patients. All mechanically ill patients were classified, even those sicker with tracheostomy and those that could not finish weaning, thereby enabling comparisons among different ICUs. Finally, it seems that the new classification fits better in the ICU routine, especially for more severe and prolonged weaning patients.