Meta-Analysis Of The Value Of Bronchoalveolar Lavage Fluid Amylase In The Diagnosis Of Aspiration Pneumonia

BACKGROUNDAspiration pneumonia(AP)is defined as pneumonia caused by aspiration of oropharyngeal or stomach contents into lower respiratory tract or lung which the patients can not discharge it.Compared to the non-aspiration pneumonia,AP is a more serious pneumonia.AP correlates with ICU admission,in-hospital mortality,hospital length of stay and total hospital charges.The diagnosis of AP depends on three aspects universally:obvious aspiration history,risk factors of aspiration and typical imaging features.Due to lack of the gold standard for the diagnosis of AP and markers,it is difficult to find early AP.The diagnosis of AP still remai n challenging.In recent years,studies found that the level of bronchoalveolar lavage fluid(BALF)amylase have strong correlation with aspiration risk factors and the number of bacteria in BALF of AP patients.BALF amylase can be used as an indicator for the diagnosis of AP with huge potenti al.OBJECTIVESThe purpose of this study was to investigate the diagnostic value of BALF amylase in AP.METHODS2 researchers searched 7 databases independently published in English or Chinese up to September 30,2020.The search used the terms with"pneumonia or aspiration or dysphagia or wallowing function or deglutition disorders or swallowing disorders"and"saliva amylase or amylases".We evaluate methodological quality of the included studies in Review Manager5.3.Meta analysis was performed using the Metan module of STATA SE15.1and Meta-Di Sc 14.0 and calculated sensitivity(SEN),specificity(SPE)and area under the SROC curve(AUC).We measured studies heterogeneity by using I~2statistics.We conducted sensitivity analyses in order to verify the stability of this study.RESULTSA total of 1269 articles were retrieved from all databases.Articles were import into the Endnote software.First,248 repeated articles were removed.For further research,999 unrelated articles were excluded by reading title and abstract of articles.8 meeting abstracts and 6 articles which statistics do not match that definition were deleted.Finally,8 studies were included in this meta-analysis.This study involved 1057 patients.The results showed that the pooled SEN was 79%(95%CI:69%,86%),the pooled SPE was 77%(95%CI:54%,90%).And AUC was 84%(95%CI:76%,85%)for BALF amylase.The pooled results had high heterogeneities.In the subgroup analysis,8studies were grouped according to diagnostic criteria,sample size and regions.It was found that heterogeneities do not decrease.The source of heterogeneity might be related to diagnostic criteria,sample size and regions.Sensitivity analysis showed the result of this meta-analysis is stable.Publication bias was inevitable due to the small numbers of included studies.CONCLUSIONSThe SEN and SPE of BALF amylase in diagnosis of AP remains high,BALF amylase could be used as a biomarker for the diagnosis of AP.