[Evaluation of T tube trial as a strategy of weaning from mechanical ventilation]

Weaning from mechanical ventilation (MV) is an important strategy to reduce morbidity and mortality in critical care patients. In this setting, this study aimed at evaluation of T-tube trial (TT) in weaning from MV.

Patient admitted in the ICU were included if they present the following inclusion criteria: MV > 24 hours, no neuromuscular disorders, PaO2/FiO2 ratio >200, hemodynamic stability, reversion of the cause of respiratory failure, adequate respiratory drive. All were submitted to TT. Failure was defined by the presence of one of these symptoms: RR > 30 ipm, hypoxemia, tachycardia, arrhythmia, hypertension or hypotension. After two hours of TT, patients without failure criteria were extubated. After 48 hours of adequate spontaneous respiration the patient was considered successful weaned. Results were considered significant if p < 0.05.

Forty-nine patients were included with a mean age 51.8 ± 21.7 years. The incidence of ARDS and septic shock were 26.5% and 32.7% and mean duration of MV was 11.9 ± 13 days. Discontinuation of MV occurred in 79.2%, reintubation in 31.6%, in a mean time of 13 ± 8.7 hours and in 75% of the cases it was due to respiratory failure. There was no correlation between success in TT and hemoglobin levels, PaO2/FiO2 ratio, age, gender, prior ARDS or septic shock. Weaning success was not correlated with none of the above variables.

TT was adequated for weaning from mechanical ventilation in the majority of the cases. However, reintubation rate was high. Possible causes are the long period of TT, prior mechanical ventilation or the failure in the criteria used to indicate extubation.