Abstract:

Objective To explore the value of ultrasonic measurement of diaphragm thickening fraction combined with diaphragm displacement in predicting successful weaning of patients with mechanical ventilation. Methods One hundred and fourteen patients who received mechanical ventilation were divided into successful weaning group（n = 87）and failed weaning group（n = 27）. The changed of the diaphragm function such as dia⁃ phragmatic thickness at the end of expiration（DTee），diaphragm thickening fraction（DTF）and diaphragmatic displacement were compared and analyzed. Multivariate logistic regression was used to analyze the influencing factors affecting the success of weaning. The ROC curve was used to analyze the potential indicators in predicting the accuracy of weaning outcome. Results The initial diaphragm thickening fraction in the successful weaning group was significantly higher than that in the failed weaning group（P < 0.05）. The diaphragmatic thickness at the end of expiration，diaphragm thickening fraction and diaphragmatic displacement during initial spontaneous breathing trial（SBT）in the successful weaning group were significantly higher than those in the failed weaning group（P < 0.05）. Multivariate logistic regression analysis showed the diaphragm thickening fraction and the diaphragm displacement during SBT were independent risk factors for weaning failure. The accuracy of diaphragm thickening fraction（AUC = 0.895，95%CI：0.832 ~ 0.957）and diaphragm displacement（AUC = 0.887，95%CI：0.821 ~ 0.954） in predicting weaning success was higher than the rapid shallow breathing index（AUC = 0.790，95%CI：0.687 ~ 0.892）. The prediction accuracy of diaphragm thickening fraction combined with diaphragm displacement（AUC = 0.966，95%CI：0.932 ~ 1.000）is higher than the single parameter. Conclusion Diaphragm thickening fraction and diaphragm displacement during SBT are independent risk factors of weaning failure in patients with mechanical ventilation. Diaphragm thickening fraction and diaphragm displacement are effective predictors of successful wean⁃ ing of mechanical ventilation and the combination of the two has higher value than the single parameter.

Key words:

diaphragm, diaphragmatic displacement, diaphragm thickening fraction, mechanical ventilation, weaning