Efficacy of echocardiography during spontaneous breathing trial with low-level pressure support for predicting weaning failure among medical critically ill patients.

Background: Echocardiography was reported to be a good predictor of weaning failure when using T-piece method, but information about its efficacy in a pressure support setting is scarce. This study aimed to investigate the efficacy of echocardiography during spontaneous breathing trial with low-level pressure support for predicting weaning failure among medical critically ill patients.

Methods: This prospective cohort study was conducted in adult respiratory failure patients that tolerated low pressure support weaning for 30 minutes. Echocardiogram was performed during pressure support ventilation before extubation. Weaning failure was defined as reintubation within 48 hours.

Results: Of the 52 included patients (mean age 65.9 ± 17.8 years), 14 experienced weaning failure. Severe pneumonia, metabolic acidosis, and septic shock were the leading causes of respiratory failure. Univariate analysis identified BMI > 24, peak A wave < 100 cm/s, E/Ea > 14, and inferior vena cava maximum diameter (IVC ) > 17 mm as factors associated with reintubation. Multivariate analysis revealed E/Ea > 14 and IVC  > 17 mm to be independent predictors of weaning failure.

Conclusion: Inferior vena cava maximum diameter > 17 and E/Ea ratio ≥ 14 independently predict weaning failure in patients with preserved left ventricular systolic function. This finding confirms that preload status of both ventricles plays a major role in weaning failure.