Through the literature screening of MyomiRX 7, the detection of mechanical ventilation group, difficult withdrawal unit and healthy adult plasma levels of MyomiRX in the evaluation of function and skeletal muscle thickness of the diaphragm, the correlation analysis of 7 kinds of MyomiRX and diaphragmatic dysfunction. The research value of this project is to explore the predictive value of plasma MyomiRX level on diaphragmatic dysfunction in patients with mechanical ventilation, and to lay the foundation for finding the target of VIDD diagnosis and treatment

1. research content (1) screening MyomiR through literature review (2) selection of mechanical ventilation group, difficult withdrawal units and three healthy adult groups, method for the detection of plasma MyomiRX level and clinical assessment of diaphragmatic function, observation of the relationship between MyomiRX level and diaphragmatic dysfunction, prediction of plasma MyomiRX levels in patients with mechanical ventilation for diaphragmatic dysfunction in value.
2. research objectives Objective to investigate the predictive value of specific minute RNA in plasma muscle tissue on diaphragmatic dysfunction in mechanical ventilation patients Experimental grouping (1) the control group of mechanical ventilation (time of examination, preoperative, admission to ICU and before extubation); (2) difficulty in withdrawal of units (first days, third days and seventh days after the failure of the test time for the first withdrawal); (3) the healthy control group (after the test time was selected)

Inclusion Criteria:

healthy control group: healthy volunteers mechanical ventilation control group: patients who underwent elective cardiothoracic surgery after scheduled and controlled mechanical ventilation for more than 12h were transferred to ICU (including coronary artery bypass grafting and valve replacement) difficult weaning: difficult to diagnose patients in ICU (weaning time from mechanical ventilation for >48 hours and first SBT failure)

Exclusion Criteria:

1. severe respiratory depression, high paraplegia and neuromuscular lesions;
2. esophageal obstruction, esophageal perforation, severe esophageal varices bleeding, upper gastrointestinal surgery and other reasons can not be placed EAdi catheter;
3. thoracic deformity and diaphragmatic hernia;
4. serious heart, liver, kidney and other organ failure, hemodynamic instability;
5. pregnancy;
6. the end of the tumor or the family member give up the active treatment

healthy control group: healthy volunteers mechanical ventilation control group: patients who underwent elective cardiothoracic surgery after scheduled and controlled mechanical ventilation for more than 12h were transferred to ICU (including coronary artery bypass grafting and valve replacement) difficult weaning: difficult to diagnose patients in ICU (weaning time from mechanical ventilation for >48 hours and first SBT failure)