Objective To systematically evaluate the effectiveness and safety of Xuanbai Chengqi Decoction（宣白承气汤） combined with Western medicine conventional therapy in the treatment of acute lung injury（ALI） and acute respiratory distress syndrome（ARDS）. Methods Electronic databases（CNKI

Wanfang

VIP

CBM

TCMLARS

PubMed

Embase

and the Cochrane Library） and clinical trial registration platforms（ChiCTR

ClinicalTrials.gov） were searched from inception to January 31 st

2020. Randomized controlled trials（RCTs） of Xuanbai Chengqi Decoction or the modified Xuanbai Chengqi Decoction for ALI/ARDS were included. The Cochrane risk of bias tool was used to evaluate the methodological quality of included RCTs. RevMan 5.3 software was used to calculate the outcomes including effective rate

mortality

oxygenation index

interleukin 6（IL-6）

interleukin 10（IL-10） and tumor necrosis factor alpha（TNF-α）. Trial sequential analysis（TSA） was performed regarding effective rate. Grading quality of evidence and strength of recommendations（GRADE） approach was used to assess the certainty of the evidence. Results Twelve RCTs involving 705 patients were included. The results from meta-analyses showed that Xuanbai Chengqi Decoction combined with Western medicine conventional therapy improved the effective rate [relative risk（RR） = 1.45

95% confidence interval（CI） 1.28 to 1.65]

reduced mortality（RR = 0.55

95%CI 0.38 to 0.81）

increased oxygenation index [mean difference（MD） = 26.11

95%CI 21.90 to 30.32]

increased IL-10 level（MD = 26.76

95%CI 17.67 to 35.85）

and reduced IL-6 level（MD =-2.04

95%CI-2.61 to-1.47） and TNF-α level [standard mean difference（SMD） =-0.55

95%CI-0.82 to-0.29]. The difference were all significant

and no serious adverse events occurred. The TSA result accepted the anticipated effect of Xuanbai Chengqi Decoction on effective rate. According to GRADE

the certainty of evidence on effective rate

mortality

oxygenation index and TNF-α were of low quality

and that of IL-6 and IL-10 were of very low quality

which made a weak recommendation of the treatment. Conclusion Xuanbai Chengqi Decoction combined with conventional Western medicine therapy can increase the effective rate

reduce mortality

relieve the inflammatory reaction

and is safe for the treatment of ALI and ARDS. However

the conclusion needs to be further confirmed due to small sample size and low quality.