Systematic review and meta-analysis: value of venous blood gas in the diagnosis of acute exacerbation of chronic obstructive pulmonary disease in Emergency Department.

BACKGROUND: at present, arterial blood gas (ABG) analysis is widely used in the diagnosis and treatment evaluation of acute exacerbation of chronic obstructive pulmonary disease (COPD) in emergency department, but it has the risk of thrombosis and bleeding. In recent years, venous blood gas (VBG) analysis has become more and more popular, but its clinical diagnostic value in emergency patients with acute exacerbation of COPD remains unclear.

METHODS: relevant clinical studies on the diagnosis of acute exacerbation of COPD by blood gas analysis were searched in Medline, Excerpta Medica Database (EMBASE), Elton B. Stephens. Company (EBSCO), OVID, China Biomedical Database, and Wanfang Database from the establishment of the database to January 2010 to September 2021, Meta-analysis was performed on the data with RevMan5.3. The differences of blood gas analysis indicators potential of hydrogen (pH), partial pressure of carbon dioxide (PaCO2), and hydro-carbonate (HCO3) were compared between the arterial blood gas group and the venous blood gas group. Heterogeneity of results was assessed with Chi2 test and I2 in RevMan5.3.

RESULTS: a total of 7 articles with 1,257 subjects were included in this study. Newcastle-Ottawa scale (NOS) scores were higher than six points. In relation to the ABG analysis and VBG analysis, there was no significant difference in the potential of hydrogen (pH) [mean difference (MD) =-0.00, 95% confidence interval (CI) =0.05-0.04, Z=0.19, P=0.85]; however, there were significant differences in the partial pressure of carbon dioxide (PaCO2) (MD =5.32, 95% CI =3.32-7.33, Z=5.20, P<0.00001) and hydro-carbonate (HCO3) (MD =1.05, 95% CI =0.27-1.83, Z=2.63, P=0.009).

CONCLUSIONS: there were differences between ABG and VBG in the diagnosis of patients with acute exacerbation of COPD in the emergency department. Due to the small number of included literatures, further verification is needed.