Role of Bedside Ultrasonography in Assessment of Diaphragm Function as a Predictor of Success of Weaning in Mechanically Ventilated Patients

Abstract

Background Weaning failure is common in mechanically ventilated patients, and if ultrasound can predict weaning outcome remains controversial. The purpose of this study was to evaluate the diaphragmatic function (thickness and excursion) measured by ultrasound as a predictor of the extubation outcome. Methods We included 62 mechanically ventilated patients from the chest intensive care unit in this study. Sixty-two patients who successfully passed the spontaneous breathing trial (SBT) were enrolled. The transthoracic ultrasound of the diaphragm was performed during an SBT to the assess diaphragmatic function (excursion and thickness), and they were classified into the successful extubation group and the failed extubation group. Results There was a statistically significant increase in the successful extubation group in the diaphragmatic excursion and thickness fraction (p<0.001), a statistically significant negative correlation between the diaphragmatic function and the duration of the mechanical ventilation, and a statistically significant negative correlation between the diaphragmatic excursion and the Acute Physiology and Chronic Health Evaluation II. The diaphragmatic excursion cut-off value predictive of weaning was 1.25 cm, with a specificity of 82.1% and a sensitivity of 97.1% respectively, and the diaphragmatic thickness cut-off value predictive of weaning was 21.5%, with a specificity of 60.7% and a sensitivity of 91.2%, respectively. Conclusion The diaphragmatic ultrasonography was found to be a promising tool for predicting the extubation outcome for mechanically ventilated patients.

Keywords

• weaning
• transthoracic ultrasound
• diaphragmatic excursion
• diaphragmatic thickness fraction
• successful extubation
• failed extubation