Xu Xiaoting, Zhang Junyi， C hang Wei，Sun Qing，Yang Yi，Qiu Haibo,Liu Ling

1. Correlation between muscle specific microRNA in plasma and diaphragmatic dysfunction in patients undergoing mechanical ventilation Xu Xiaoting, Zhang Junyi，Chang Wei，Sun Qing，Yang Yi，Qiu Haibo,Liu Ling Department of Critical Care Medicine, Zhongda Hospital, Southeast University

2. Background and Aim • Mechanical ventilation may cause ventilator-induceddiaphragmatic dysfunction (VIDD) • Mechanical ventilation induced diaphragmatic wasting atrophy is the most important mechanism of VIDD • miRNA is widely participated in regulation of muscular atrophy • To investigate the relationship between plasma miRNA and diaphragmatic function in mechanical ventilation patients

3. Measurement of skeletal muscle thickness by Ultrasound Detection of plasma MyomiR level Measurement of diaphragmatic function by Ultrasound Method Included patients • Screening of muscle specific miRNA • Single-center prospective study • Undergoing scheduled cardiac surgery whosetotaltime of controlled MVis greater than 12h and less than 48 h • Exclusion criteria: Severe respiratory central depression, can not placed EAdi catheter, pregnancy one day before operation before extubation the third days after operation

4. Result →no significant change in the thickness of skeletal muscle →level of plasma miR-1 and miR-206 was significantly low before extubation

5. Result- short time mechanical ventilation lead to decrease of diaphragmatic function decrease of plasma miR-206 level positively correlated with the decrease of diaphragm function Note: compared with 1 days before operation, * P<0.05; compared with before extubation, # P<0.05

6. Conclusion The decrease of plasma miR-206 level is positively correlated with the decrease of diaphragm function in mechanically ventilated patients Thank you