Comparison between electrical cardiometry and lung ultrasound in the assessment of lung water in mechanically ventilated patients

Abstract Background Weaning from mechanical ventilation may lead to extubation failure; however, it is advised to wean patients from it earlier to prevent the problems of extended continuous ventilation. Aim of the study This study aimed to compare electrical cardiometry and lung ultrasound in assessing lung water as predictors of weaning failure from invasive mechanical ventilation in patients with preserved ejection fraction heart failure (HFpEF) by measuring thoracic fluid content (TFC) by cardiometry and B lines by ultrasound. Patients and methods This research comprised 70 mechanically ventilated studied cases diagnosed with HFpEF, deemed suitable for weaning, and admitted to the Critical Care Medicine Department at Alexandria Main University Hospital between February 2023 and February 2024. All enrolled patients underwent electrical cardiometry for measuring (TFC) and lung ultrasound to measure B lines. Weaning failure was characterized by the necessity for reintubation within 48 h post-extubation. Patients were segregated into two categories: those who successfully weaned and those who experienced weaning failure. Both groups were then compared based on the study’s outcomes. Results In this study, 52 (74.28%) patients underwent successful weaning, while 18 (25.71) patients underwent failed weaning. B lines were significantly higher in the failed weaning group (18.14 ± 2.35) vs (7.48 ± 2.1) in the successful weaning group. They can significantly predict weaning failure (AUC = 0.878, P value < 0.001). The suggested cut-off value (> 12) showed 72.2% sensitivity and 96.2% specificity. TFC (kΩ −1 ) was significantly higher in the failed weaning group (61.47 ± 5.16) vs (42.50 ± 10.47) in the successful weaning group. TFC was a significant predictor of failed weaning from mechanical ventilation (AUC = 0.950, P value < 0.001). The suggested cut-off value (> 52.8 kΩ −1 ) gave 94% sensitivity and 86% specificity. Conclusion Both B-lines by LUS and TFC by cardiometry are good predictors for weaning failure in HFpEF patients. However, TFC seems to be more sensitive but less specific than LUS.