Prognostic value of central venous -to -arterial carbon dioxide difference and early lactate clearance rate in septic shock

doi:10.3969/j.issn.1002-1949.2015.07.004

Abstract：Objective To investigate the clinical value of central venous -to-arterial carbon dioxide diference ( Pcv-aCO2 ) and early lactate clearance rate in evaluating the prognosis of patients with septic shock .Methods Eighty -two consecutive septic shock patients in Intensive Care Unit ( ICU) underwent early goal -directed therapy ( EGDT) were studied prospectively from January 2010 to October 2013 .6 h Pcv-aCO2 , the APACHE Ⅱscore and SOFA score were evaluated .Arterial blood lactate level were measured at 0, 6, 24 h after inclusion and calculated lactate clearance rate .Based on 6 h Pcv-aCO2 (6 mm Hg as limit), the patients were divided into A group ( <6 mm Hg) and B group (≥6 mm Hg) , which compared by SOFA score , lactate clearance rate and mortality .According to 6 h lactate clearance rate , the patients were divided C group (≤10%) and D group ( >10%) .The two groups of patients were compared by 28-day mortality.According to the 28-day disease outcome , the patients were divided into death group ( n=32 ) and survival group ( n=50 ) , which were compared by APACHEⅡscore and lactate level .Results The mortality and SOFA score of B group were higher than A group (P<0.05), and lactate clearance rate of B group was lower than A group (P<0.05).The level of 6 h Pcv-aCO2 was negatively correlated with the 6 h lactate clearance rate (r=-0.324, P=0.003).There was significant difference in mortality between C and D group (P<0.05).Significant differences of the lactate at 0, 6, 24 h and were found between death group and survival group ( P<0.05).The APACHEⅡ score of death group was higher than the survival group ( P <0.05 ). Conclusion 6 h Pcv-aCO2 and 6 h lactate clearance rate may serve as a useful index for predicting the prognosis of patients with septic shock .