The value of the excursion of diaphragm tested by ultrosonography to predict weaning from mechanical ventilation in ICU patients

Abstract

Objective: To evaluate the excursion of the diaphragm and analyze the value in predicting weaning from mechanical ventilation in intensive care unit patients. Methods: The patients with mechanical ventilation (>48 hours) in ICU at Hebei Forth Medical University Hospital from June 2014 to December were classified into a success group or a failure group according to the weaning outcome. T-piece spontaneous breathing (SBT), airway occlusion pressure at 0.1 sec (P(0.1)) and maximal inspiratory pressure (MIP), rapid shallow breathing index (RSBI) and P(0.1)/MIP were measured or calculated. During the period of the 1st hour SBT, the excursion of diaphragm was measured with ultrasonography. The predictive value of each parameter to weaning was evaluated with ROC curve. Results: A total of 98 patients were enrolled in this study, including 74 successfully weaning and 24 failed. There were significant differences between two groups(success group and failure group) in P(0.1)[(2.00±2.00)cmH(2)O (1 cmH(2)O=0.098 kPa) vs (3.00±2.75)cmH(2)O, P<0.05], RSBI (39.14±16.81 vs 52.00±19.18, P<0.05), left diaphragmatic excursion [(1.12±0.97)cm vs (0.69±1.00)cm, P<0.001], right diaphragmatic excursion(1.87±0.75)cm vs (1.17±0.76)cm, P<0.001] and mean value of left and right diaphragmatic excursion [(1.57±0.52)cm vs (0.83±0.53)cm, and P<0.001]. The ventilation time [2.00(2.00-4.00)d vs 4.00(2.00-5.00)d], ICU hospital lengths of stay [4.50(3.00-7.25)d vs 8.50(6.25-15.25)d] and total hospital lengths of stay[20.00(15.00-25.25)d vs 25.00(20.25-37.25)d] were also statistically significant in success group and failure group respectively (all P<0.05). The cutoff value of diaphragmatic excursion for predicting successful extubation was determined to be 1.14 cm by ROC curve analysis. The sensitivity of diaphragmatic excursion to predict successful weaning was 89.2% and the specificity was 75.0%, the AUC(ROC) was 0.849. Conclusion: As an early predictor of diaphragmatic dysfunction, diaphragmatic excursion is probably superior to the traditional parameters in predicting weaning from ventilator in ICU patients.