Abstract: ABSTRACT:Objective The early monitoring in arterial blood lactic acid clearance rate and central venous blood oxygen saturation (ScVO2 ) on the prognosis of critical patients were discussed.Methods A total of 189 ICU critical patients treated in our hospital were divided into four groups according to Acute Physiology and Chronic Health Evaluation (APACHE Ⅱ ):patients greater than > 30 belonged to group A;ranged from > 20 - 30 belonged to group B;ranged from >10-20 belonged to group C;and ranged from 0-10 belonged to group D.Then, the blood lactate clearance rate,ScVO2 ,mortality were compared among the four groups in their early treatment.All the patients received conventional treatment and professional care and after 28 days of treatment,and they were divided into death group (61 patients)and survival group(128 patients)according to whether survive or not.And then,the members in both groups were tested by APACHE Ⅱ grade,along with the measurement of early blood lactate clearance rate and ScVO2 .All the data were mortality and their relativity studied.Results Blood lactate clearance rate,and ScVO2 ,mortality in various APACHE Ⅱgroups were significantly different (P <0.05);APACHE Ⅱ grade in death group was significantly higher than that in survival group (P <0.01);lactate clearance rate tested 6 hours after treatment in death group was lower than that in survival group (P < 0.01);ScVO2 in death group was significantly lower than that in survival group (P <0.01);Through correlation analysis,APACHE Ⅱ score and lactate clearance tested 6 hours of treatment were negatively correlated (r =-0.618,P <0.05),while APACHE Ⅱ score had significant positive correlation with ScVO2 (r = -0.695,P < 0.05).Conclusion ScVO 2 and blood lactate clearance rate have much to do with the severity of the disease,and definitely,the prognosis and recovery can be reflected by ScVO2 and early blood lactate clearance rate deserves recommendation to clinical use and research.

Key words: critical illness, metabolic clearancrate, lactic acid, oximetry, prognosis