Ventilatory Weaning Guided by a New Index

Mechanical ventilation (MV) is an essential therapy for patients with acute respiratory failure. The ventilatory weaning process should be started when the precipitating causes of the use of the ventilatory prosthesis are resolved. Inappropriately slow weaning exposes the patient to unnecessary discomfort, increases the risk of complications and increases the cost of hospital treatment. In this sense, indices that can predict successful weaning are of great value. Our study aimed to evaluate the performance of a new ventilatory weaning index, the timed inspiratory effort index (TIE index), as a weaning predictor in comparison with the traditionally used spontaneous breathing test (SBT). The study is a randomized controlled trial of a cohort of mechanically ventilated patients over 24 hours admitted to the ICU of Hospital e Clínica São Gonçalo (HCSG), located in the city of São Gonçalo, State of Rio de Janeiro, Brazil. The TIE index is calculated as the ratio of the maximum inspiratory pressure developed in the last 30 seconds of a 60 second period of unidirectional airway occlusion by the time required to reach this value.

Inclusion and exclusion criteria

Our study included patients over 18 years old, under mechanical ventilation, who remained for more than 24 hours of invasive ventilatory assistance and who were able to start the process of weaning. Exclusion criteria comprised tracheostomy, chronic neurological disorders, low level of alertness, and chronic immune suppression states, including positive serology for HIV.