Point-of-Care Ultrasound Evaluation of Diaphragm as a Predictor of Extubation Success in Mechanically Ventilated, Malnourished, End-Stage Liver Disease Pretransplant Candidates-Observational Cohort Study.

Background: Ultrasound evaluation of diaphragmatic anatomy and function has recently gained traction as a simple and useful tool to assess the extubation readiness in mechanically ventilated patients, nevertheless, how applicable this approach is in the population of chronically debilitated patients on mechanical ventilation (MV) remains unclear.

Objective: To evaluate ultrasonographic assessment of diaphragmatic thickening fraction (ΔTDI%) as a predictor of extubation success in the population of end-stage liver disease (ESLD) malnourished patients on MV.

Design: Prospective, single-center, observational cohort study.

Methods: We used point-of-care ultrasound to evaluate ΔTDI% and diaphragm thickness during expiration (T _exp) and inspiration (T _insp) as predictors of extubation success in ESLD patients undergoing weaning from mechanical ventilation. The primary end-point was extubation tolerance (ET) assessed at 48 h.

Results: Of 70 enrolled patients, 82.4% (N = 56) tolerated extubation. While there was no difference in ΔTDI% between those who failed extubation (EF) compared to ET at 48 h (21.2% vs 20.1%, P = .64), diaphragms were thicker at expiration in ET patients (T _exp 29.5 ± 8.1 vs 24.8 ± 5.2 mm, P = .047). Commonly used clinical weaning parameters, including rapid-shallow breathing index (RSBI) and negative inspiratory force (NIF) correlated better with diaphragm thickening fraction ΔTDI% than diaphragm thickness indices but were inferior predictors of extubation success compared to T _exp..

Conclusion: Point-of-care ultrasonographic assessment of the diaphragm offers insight into the function of respiratory muscles and the limited ability to predict extubation success. Further research is necessary to better understand its potential use in MV liberation in patients with ESLD and malnutrition.