ABSTRACT

Background: Diaphragm dysfunction (DD) is highly prevalent in critically ill patients and is one of the major causes of respiratory failure and prolonged time of removing patients from the mechanical ventilation. Among the various methods of evaluating diaphragm dysfunction, ultrasonography (US) is a noninvasive, rapid and accessible method in the patient's bedside.

Aim: To evaluate diaphragm dysfunction for predicting extubation time in critically ill patients in ICU with ultrasonography.

Methods: This prospective observational study was performed on critically ill patients admitted to intensive care unit under mechanical ventilation for at least 48 hours. All patients were evaluated by ultrasonography for evaluation of diaphragm dysfunction. Ultrasonography was performed using M-mode to measure diaphragm thickness and excursion 24 hours before extubation. The area under curve (AUC) of ROC was calculated to determine the ability of diaphragm ultrasonography to predict the success of extubation.

Results: In this study, there were 3 cases (2.83%) of extubation failure and in other cases, extubation was successful (97.17%).There was a significant positive correlation between excursion and diaphragm thickness (P <0.0001). The area under the ROC for the right and left thickness was 0.898 (95% CI: 0.824-0.948; P <0.001) and 0.975 (95% CI: 0.930-0.997; P <0.0001) and for right and left excursions was 0.841 (95% CI: 0.758-0.905; P <0.002) and 0.989 (95% CI: 0.945-1.000; P<0.0001) respectively.

Conclusion: The results of this study showed that both ultrasound thickness and diaphragm excursion indices are useful in evaluating diaphragm function to predict extubation success. In addition, it seems that the diaphragm excursion rate is a better indicator for predicting extubation than the diaphragm thickness in critically ill patients.

Keywords: Extubation, Diaphragm Dysfunction, Ultrasonography, Excursion, Thickness