Diaphragm and Lung Ultrasound Indices in Prediction of Outcome of Weaning from Mechanical Ventilation in Pediatric Intensive Care Unit

Abstract

Objective To predict the added value of diaphragmatic and lung ultrasound indices (US) in anticipation of the outcome of mechanical ventilation of pediatric patients in the intensive care unit. Methods This prospective study was conducted in Zagazig University, Pediatric Hospitals, PICU; Egypt. One hundred six mechanically ventilated children aged between 1 mo to 170 mo were included in the study. All patients were candidates for weaning and have been given a chance for spontaneous breathing trial (SBT), during which diaphragmatic and lung US was performed for them. The diaphragm thickening fraction (DTF), the diaphragmatic excursion and the lung US score (LUS), that included 4 US aeration forms, were assessed. Results There were statistically significant differences between patients with failed weaning and those with successful weaning regarding DTF, diaphragmatic excursion and LUS (p < 0.001). The best cut-off value of DTF, diaphragmatic excursion, and LUS for predicting weaning failure was ≥23.175%, ≥ 6.2 mm, and ≥ 12 with an AUC (area under curve) of 0.932, 0.876, and 0.934, respectively. Conclusions Diaphragmatic and lung US add a quick, accurate and non-invasive indices to the weaning readiness parameters compared to the other standard parameters alone. So, it is recommended to be added to the predictive parameters of weaning outcome.

Diaphragm and Lung Ultrasound: A Bedside Tool to Hasten Weaning Off from Ventilation

“…Best cut-off values for DTF, DE and LUS for predicting weaning failure were < 23.17%, < 6.2 mm, and ≥ 12 respectively. But the current study has unusually high extubation failure rate of 39.6% [4].Previous study in 50 children also demonstrated similar cut-off of ≥21% for DTF for successful weaning with successful weaning in 78% children [2]. Recent meta-analysis of 742 adults reported summary AUROC of 0.838 and 0.859 for DTF and DE, respectively [5].…”

“…Ultrasound can assess percentage change in diaphragmatic thickness from expiration to inspiration (diaphragmatic thickening fraction, DTF) and amplitude of diaphragmatic dome movements in respiratory cycle (diaphragmatic excursion, DE) which are indicators of strength of diaphragmatic contractions [2]. Lung parenchyma is assessed by a semi-quantitative score (Lung Ultrasound Score, LUS) based on frequency of B-lines in different lung fields (score 0 to 3 in each field), with higher score indicating worse parenchymal status [3].In a study published in this issue of the journal by Abdel Rahman DA et al, 106 mechanically ventilated children were examined with diaphragm and lung ultrasound during SBT [4]. They found that infants with weaning failure had significantly lower DTF and DE, and higher LUS compared to successful weaning (p < 0.001 for all comparisons).…”

“…LUS has not been previously studied in children to predict extubation outcomes. Studies in adults demonstrated significantly higher weaning failure and respiratory distress with higher pre-extubation LUS [3,7].Both the pediatric studies suggest that weaning outcome can be predicted by ultrasound based diaphragmatic function parameters while results of the large multi-centric study are discouraging for its use in adults [2,4,6]. Strength of respiratory efforts are dependent mainly on diaphragm in infants and young children due to their horizontally placed ribs and compliant chest wall, while the contribution of chest wall muscles is greater in adults.…”

“…Strength of respiratory efforts are dependent mainly on diaphragm in infants and young children due to their horizontally placed ribs and compliant chest wall, while the contribution of chest wall muscles is greater in adults. This could possibly explain better performance of diaphragmatic ultrasound in infants and young children included in the above pediatric studies.The study by Abdel Rahman et al has a few limitations [4]. The authors have not reported the outcome of spontaneous breathing trial (SBT) in the subjects: of 106 children, how many failed a SBT?Most of the available studies are observational with no comparator arm for estimating added benefit of DTF and DE…”

“…In a study published in this issue of the journal by Abdel Rahman DA et al, 106 mechanically ventilated children were examined with diaphragm and lung ultrasound during SBT [4]. They found that infants with weaning failure had significantly lower DTF and DE, and higher LUS compared to successful weaning (p < 0.001 for all comparisons).…”