Objective To investigate the judgment value of the central venous-to-arterial carbon dioxide difference(Pcv-aCO2)on the prognosis of traumatic hemorrhagic shock(THS).Methods A retrospective analysis of the clinical data of 60 patients with THS admitted to the First Affiliated Hospital of Gannan Medical College from May 2019 to September 2020.According to the outcome,they were divided into the survival group(36 cases)and the death group(24 cases).The levels of Pcv-aCO2,central venous blood oxygen saturation(ScvO2),central venous pressure(CVP),base excess(BE),blood lactic acid and acute physiology and chronic health evaluation(APACHEⅡ)score between the two groups were compared.To evaluate the judgment value of Pcv-aCO2 detection,ScvO2 detection,Pcv-aCO2 combined with ScvO2 detection on the prognosis.Results Six hours after resuscitation,the levels of Pcv-aCO2 and blood lactic acid of the survival group were lower than those of the death group,the levels of ScvO2 and BE of the survival group were higher than those of the death group,the differences were statistically significant(P<0.05).There were no statistically significant of CVP levels and APACHEⅡscore between the two groups(P>0.05).The levels of Pcv-aCO2 and blood lactic acid at six hours after resuscitation were lower than those before resuscitation in the survival group,and the levels of ScvO2 and BE at six hours after resuscitation were higher than those before resuscitation in the survival group,with statistically differences(P<0.05).There were no statistically significant of CVP levels before and after resuscitation in the survival group(P<0.05).The judgment value the prognosis was the highest of Pcv-aCO2 combined with ScvO2 detection on the prognosis(Pcv-aCO2 combined with ScvO2 detection vs. Pcv-aCO2 detection: Z=2.291, P<0.05;Pcv-aCO2 combined with ScvO2 detection vs.ScvO2 detection: Z=2.144, P<0.05),and the sensitivity and specificity were 85.71% and 82.69%,its better than the ScvO2 detection and Pcv-aCO2 detection.Conclusion Early detection of Pcv-aCO2 combined with ScvO2 could accurately judgment the prognosis of patients with THS,it has important clinical guiding value.