DTF

Q: What is the significance of diaphragmatic thickening fraction (DTF) in ventilator liberation?

Answer: As ultrasound at the bedside, popularly known as POCUS (Point of Care Ultrasound), is gaining popularity in ICUs, ultrasound (US) of the diaphragm has also been evaluated in predicting weaning success (liberation for ventilator). The formula for DTF is

DTF = [thickness at end-inspiration – thickness at end-expiration] / thickness at end-expiration × 100

DTF ≥ 27.9% predicts successful weaning with good sensitivity.

Some experts refined this technique further by applying the ratio of respiratory rate (RR) to DTF to predict extubation success. The right-sided diaphragmatic RR/DTF ratio using a cut-off point at ≤ 0.81 is found to have a sensitivity of 87.7%, a specificity of 75%, and areas under the receiver operating characteristic curve (AUROC) of 0.762 for predicting successful extubation, with a p-value of 0.013 (reference #3).

#ventilators

#pulmonary

#POCUS

References:

1. Lin, H., Yao, M., Qin, Z. et al. Predictive values of ultrasonic diaphragm thickening fraction combined with integrative weaning index in weaning patients with mechanical ventilation: a retrospective study. J Cardiothorac Surg 19, 66 (2024). https://doi.org/10.1186/s13019-024-02544-x

2. Parada-Gereda HM, Tibaduiza AL, Rico-Mendoza A, et al. Effectiveness of diaphragmatic ultrasound as a predictor of successful weaning from mechanical ventilation: a systematic review and meta-analysis. Crit Care 2023; 27:174.

3. Eksombatchai, D., Sukkratok, C., Sutherasan, Y. et al. The ratio of respiratory rate to diaphragm thickening fraction for predicting extubation success. BMC Pulm Med 23, 109 (2023). https://doi.org/10.1186/s12890-023-02392-w