Objective To explore the correlation of lung ultrasound score（LUS） and the progression of severe pneumonia patients with different severity.Methods A total of 189 patients with severe pneumonia were selected

they were divided into non-critically ill group（53 cases）

critically ill group（86 cases）

very critically ill group（50 cases）according to the acute physiology and chronic health（APACHEⅡ）score.All patients in each group was followed up for 3 months

and the LUS

clinical pulmonary infection score（CPIS）

trans-organ failure score（SOFA）

oxygenation index（OI）

alveolar-arterial oxygen partial pressure difference（A-aDO

2

）

and mechanical ventilation time among the groups were compared. The patients were divided into low LUS group（108 cases）and high LUS group（81 cases）according to whether LUS

>

16

and the differences of above parameters were compared between the two groups. The correlation between LUS and CPIS

SOFA

OI

A-aDO

2

mechanical ventilation time was analyzed by Pearson correlation analysis.Results The LUS

CPIS and SOFA of very critically ill group were（21.38±6.84）points

（8.02±2.43）points

（6.72±2.24）points

which were higher than those of critically ill group[（19.15±6.23）points

（7.21±2.16）points

（5.93±2.11）points]and non-critically ill group[（14.26±4.72）points

（6.58±2.07）points

（5.18±2.06）points]

.And the parameters of critically ill group were higher than those of non-critically ill group（all P

<

0.05）.The OI of very critically ill group was（103.27±41.36）mm Hg（1 mm Hg=0.133 kPa）

which was lower than that of critically ill group（131.45 ± 52.41）mm Hg and non-critical ill group（157.53 ± 60.52）mm Hg

and the parameter of critically ill group was lower than that of non-critically ill group（all P

<

0.05）.The A-aDO

2

and mechanical ventilation time of very critically ill group were（350.16 ± 137.23）mm Hg and（7.02 ± 1.45）d

which were higher than those of critical group[（306.24 ± 125.84）mm Hg

（6.23 ± 1.36）d]and non-critical group[（238.47 ± 107.16）mm Hg

（5.34 ± 1.27）d]

and the parameters of critically ill group were higher than those of the non-critically ill group（all P

<

0.05）.The scores of CPIS and SOFA of high LUS group were（8.00±2.33）points and（6.79±1.41）points

which were higher than those of low LUS group[（6.68±2.11）points

（5.74±1.32）points]

the differences were statistically significant（both P

<

0.05）.The OI of high LUS group was（106.08±43.21）mm Hg

which was lower than that of low LUS group（150.23±58.17）mm Hg.The A-aDO

2

and mechanical ventilation time of high LUS group were（363.78±141.39）mm Hg and（6.76±1.40）d

which were higher than those of low LUS group[（250.16±110.28）mm Hg

（5.76±1.33）d]

the differences were statistically significant（all P

<

0.05）.Pearson correlation analysis showed that LUS was positively correlated with CPIS

SOFA

A-aDO

2

and mechanical ventilation time（r=0.587

0.591

0.651

0.321

P=0.002

0.003

0.000

0.041）

but negatively correlated with OI（r=-0.753

P=0.000）.Conclusion LUS score is correlated with the severity of patients with severe pneumonia

which has a certain guiding value for clinical evaluation of curative effect of pneumonia.