Role of transthoracic ultrasound in assessment of successful weaning from mechanical ventilation at respiratory ICU

Background
Transthoracic ultrasonography (US) is recently introduced in the ICU to predict weaning from invasive mechanical ventilation (MV) by assessment of diaphragmatic parameters, lung US score, and assessment of cardiac function.


Aim
The objective of this investigation was to assess the accuracy of transthoracic US in identifying the parameters that are indicative of weaning success from invasive MV.


Patients and methods
This cross-sectional observational study was implemented on 30 patients in the ICU receiving invasive MV. Lung, diaphragmatic, and cardiac US were applied to each patient, and their diagnostic accuracy in anticipating the weaning success was evaluated.


Results
Thirty patients were examined; 20 were successfully extubated, while 10 were unsuccessful. With a cut-off value more than or equal to 63% and 1.35 cm, the diaphragmatic thickness fraction and diaphragmatic excursion had a sensitivity of 70 and 100%, specificity of 80 and 100%, and accuracy of 73 and 100%, respectively, for predicting the success of weaning. In contrast, the ejection fraction % demonstrated a sensitivity, specificity, and accuracy of 80% with a cut-off value of more than or equal to 52.2% also the lung US score exhibited a sensitivity of 80%, specificity of 70%, and accuracy of 77% with a cut-off value of less than 11, while inferior vena cava distensibility index shows no role in the prediction of weaning success with P value 0.277.


Conclusion
A dependable, noninvasive, and convenient method for predicting weaning success has been demonstrated by transthoracic US in the evaluation of lung score, diaphragmatic function, and cardiac function.