Added Utility of Diaphragm and lung Ultrasound Indices along with Rapid Shallow Breathing Index in Predicting Extubation Success in Children

Abstract

Introduction: Prolonged mechanical ventilation leads to diaphragm atrophy and impaired functions. An accurate assessment of its function by bedside ultrasonography during spontaneous breathing trial can add to predictive value of respiratory scores like RSBI. Lung and diaphragm ultrasound are bedside non-invasive techniques which can be used to assess the weaning readiness in children.

Methods: This study involved 50 children; newborn to 14 years of age, admitted to PICU and mechanically ventilated, during a period from November 2020 to November 2022. All patients were candidates for weaning and have been given a chance for spontaneous breathing trial (SBT), during which diaphragmatic and lung ultrasound indices were assessed. The diaphragm thickening fraction (DTF), diaphragmatic excursion (DE) and lung Ultrasound score (LUS) that included 4 US aeration forms, were assessed. Values satisfying any of the below variables were considered weaning failure; rapid shallow breathing index ≥ 8 breaths / min / ml / kg, Diaphragm thickness fraction ≤ 20%, Diaphragm excursion: ≤ 6 mm, Lung ultrasound score: ≥ 12. Sensitivity, specificity, PPV and NPV of each ultrasound parameters was calculated and compared.

Results: Statistically significant differences were found between patients with failed weaning and those with successful weaning regarding RSBI, DTF and LUSG. RSBI was found to be good predictor of weaning success. RSBI along with DTF and LUSG increased the specificity to predict weaning success rather than RSBI alone.

Conclusion: Rapid shallow breathing index of ≤ 8 is a sensitive predictor of weaning success. Lung and diaphragm ultrasound increase the specificity of RSBI to predict weaning success in critically ill children.