Diaphragmatic ultrasound as a predictor for successful weaning from mechanical ventilation

Abstract

Background Diaphragm ultrasound has lately been used in the prediction of successful weaning from mechanical ventilation. Aim To assess diaphragm thickening fraction (DTF) and mobility measured by ultrasound as predictors of successful weaning. Patients and methods This prospective study included 30 patients who were planned for weaning from invasive mechanical ventilation. Rapid shallow breathing index was measured, and diaphragmatic ultrasound was carried out to assess diaphragmatic excursion (DE) and diaphragm thickening at the time of spontaneous breathing trial. Patients were classified into two groups: group I included patients with successful weaning and group II included patients with failed weaning. Results DTF was significantly higher in group I; however, there was no statistically significant difference between the two groups regarding DE. There was a statistically significant difference between the two groups regarding rapid shallow breathing index, as it was higher in group II. The sensitivity, specificity, positive predictive value, and negative predictive value for DTF at a cutoff value more than 0.33% in prediction of successful weaning were 94, 100, 100, and 91.7%, respectively; the corresponding values for DE at a cutoff value more than 0.91 cm were 84, 37, 69.6, and 57.1%, respectively. Conclusion DTF may be useful to predict successful weaning during spontaneous breathing trial, and it has better performance than DE.

Keywords

• diaphragm thickening fraction
• diaphragm ultrasound
• diaphragmatic excursion
• mechanical ventilation