TY - JOUR AU - Huang, Daozheng AU - Ma, Huan AU - Zhong, Wenzhao AU - Wang, Xiaoting AU - Wu, Yan AU - Qin, Tiehe AU - Wang, Shouhong AU - Tan, Ning PY - 2017 TI - Using M-mode ultrasonography to assess diaphragm dysfunction and predict the success of mechanical ventilation weaning in elderly patients JF - Journal of Thoracic Disease; Vol 9, No 9 (September 27, 2017): Journal of Thoracic Disease Y2 - 2017 KW - N2 - Background: Ultrasonography (US) is a non-invasive and commonly available bedside diagnostic tool. The aim of this study was to assess the utility of M-mode US on ventilator weaning outcomes in elderly patients. Methods: This was a single center, prospective, observational study in patients aged 80 years or older who were in the medical intensive care unit, had undergone mechanical ventilation for >48 hours, and met the criteria for a spontaneous breathing trial (SBT). For 30 minutes at the start of SBT, each hemi-diaphragmatic movement and the velocity of contraction were evaluated by M-mode US. The the area under the receiver operating characteristic curve (AUROC) was calculated to determine the ability for measured variables to predict successful ventilator weaning. Results: Forty patients were enrolled and assessed, grouped by those who had US-diagnosed diaphragm dysfunction (DD; 30/40; 75%) and those who did not (10/40; 25%). Patients with DD had a significantly longer total mechanical ventilation duration (536.4±377.05 vs . 250±109.02 hours, P=0.02) and weaning time (425.9±268.31 vs . 216.0±134.22 hours, P=0.002) than patients without DD. Patients with DD also had a higher incidence of weaning failure than patients without DD (24/30 vs . 4/10, P=0.017). Analysis of the receiver operating characteristic (ROC) curve (ROC) curve showed that the optimal cut-off values to predict weaning success were >10.7 mm for the right diaphragmatic movement, and >21.32 mm/s for the right diaphragmatic velocity of contraction; AUROC were 0.839 (95% CI, 0.689–0.936) and 0.833 (95% CI, 0.682–0.932), respectively. The sensitivity, specificity, positive and negative likelihood ratios for predicting weaning success were 83.33% vs . 66.67%, 75.00% vs . 92.86%, 3.33 vs . 9.33, and 0.22 vs . 0.36, for right diaphragmatic movement and diaphragmatic contraction velocity, respectively. Conclusions: When assessed by M-mode US, DD appeared to be common in ventilated patients aged 80 years or older and was associated with a higher incidence of weaning failure. Larger right diaphragmatic movements or faster right diaphragmatic contraction velocity appeared to be good predictors of mechanical ventilation weaning success in elderly patients. UR - https://jtd.amegroups.org/article/view/15549