Objective To compare the effects of lung ultrasound-guided chest physical therapy and traditional chest physical therapy on mechanically ventilated patients with acute respiratory distress syndrome（ARDS）

and to explore the application value of lung ultrasound in ARDS chest physical therapy.Methods A total of 104 cases of mechanical ventilation patients with ARDS were selected in our hospital

according to the ARDS restrictive protective ventilation strategy they were randomly divided into control group 52 cases（received conventional treatment and mechanical assisted sputum expectoration）and ultrasound group 52 cases（received conventional treatment and ultrasound guided mechanical assisted sputum expectoration）.According to the oxygenation index（PaO

2

/FiO

2

）

each group was subdivided into mild group（200 mm Hgc Pa02/Fi02

<

300 mm Hg）

moderate group（100 mm Hg

<

PaO

2

/FiO

2

<

200 mm Hg）

and severe group（PaO

2

/FiO2

<

100 mm Hg）.The blood gas analysis and lung ultrasound scores were compared between the two groups of patients after enrollment

24 h and 48 h.Results Eleven cases of early deconditioning and 6 cases of death during the course of treatment.Finally

87 cases were included

45 cases were in the control group（14 mild cases

23 moderate cases and 8 severe case）

and 42 cases in the ultrasound group（16 mild cases

19 moderate cases and 7 severe cases）.Between the control and treatment groups

there were no statistically significant differences in oxygenation index and ultrasound scores before treatment.The oxygenation was index increased significantly and the ultrasound score was decreased significantly after 48 h of treatment in both the control and ultrasound groups

and the differences were statistically significant when compared with those before treatment（both P

<

0.05）.The differences of lung ultrasound scores at the 24 h and 48 h after treatment were statistically significant in both groups of moderate patients（both P

<

0.05）

and the differences were not statistically significant between the two groups of mild and severe patients.There was no statistically significant difference of oxygenation index between the two groups of moderate patients at 24 h after treatment

there was a statistically significant difference of oxygenation index at 48 h after treatment（P

<

0.05）

and there was no statistically significant difference of oxygenation index between the two groups of mild and severe patients at 24 h and 48 h after treatment.The oxygenation index was negatively correlated with the ultrasound score（r=-0.510

P

<

0.01）.Conclusion Compared with traditional chest physical therapy

ultrasound-guided chest physical therapy can improve oxygenation index and lung ultrasound score in some ARDS patients

which has potential clinical application value.