The predictive value of diaphragm ultrasound for weaning outcomes in surgical intensive care unit

Abstract Introduction: Multiple studies have shown that diaphragmatic ultrasound can better predict the outcome of weaning. The purpose of this study was to investigate the predictive value of two diaphragmatic ultrasound indices, diaphragmatic thickening (DTF) and excursion (DE) for weaning outcomes in the surgical intensive care unit (ICU). Patients and Methods: The study included 60 cases whose mechanical ventilation (MV) time was >48 hours, and all eligibles were divided into either the weaning success group (n=45) or the weaning failure group (n=15). Diaphragm thickness, diaphragmatic excursion (DE), and diaphragmatic thickening fraction (DTF) were measured in the zone of apposition. The rapid shallow breathing index (RSBI) was also recorded. Results: The ventilatory treatment time (p=0,002) and length of ICU stay (p=0,005) in the weaning failure group were longer than the success group. Cut-off values of diaphragmatic measures associated with successful weaning were ≥ 30% for DTF and ≥ 14 mm for DE giving a sensitivity (Se), a specificity (Sp) of 84,4%; 73,3% and 83,3%; 83,3%, respectively. By comparison, RSBI < 80 had a sensitivity of 93,3%, a specificity of 70% for determining weaning success. The areas under the ROC curves for DTF, DE and RSBI were 0,843; 0,807 and 0,873, respectively. Conclusions: Ultrasound evaluation of diaphragmatic excursion (DE) and diaphragmatic thickness fraction (DTF) could be a good predictor of weaning outcome in a surgical intensive unit. It is recommended to consider the use of these parameters with RSBI consequently to improve weaning outcomes. Keywords: Weaning, diaphragm ultrasound, diaphragmatic dysfunction, rapid shallow breathing.