The study of relationship between the change of blood lactate level and prognosis of critically ill patients in intensive care unit

Objective:To study the relationship between the change of blood lactate level and the prognosis of critically ill patients in intensive care unit(ICU).Method:One hundred and thirty-three cases of patients with elevated arterial blood lactate levels in ICU were collected in our study.The mortality of 7 d and 28 d was analyzed.All the patients were grouped according to the survival of 7 d,28 d,and the general information,lactate index(peak lactate level in ICU,8 h,24 h lactate clearance rate),the days that stay in ICU,acute physiology and chronic health evaluation score Ⅱ(APACHE Ⅱ) were recorded and compared.The patients were grouped according to peak lactate level,and the lactate clearance rate at 8 h or 24 h,the duration of high lactate,the differences in their general information,APACHE Ⅱ score,mortality at 7 d and 28 d were compared.Result:The mortality of patients with lactate increase in ICU was significantly higher in 28d than in 7 d(33.08% vs18.05%,P0.01).The peak lactate level,APACHE Ⅱ of 7 d,28 d in death group were significantly higher than that of survival group(P0.05,0.01).The 8 h,24 h lactate clearance rate of the death group were significantly lower than that of survival group(P0.01).The 7 d mortality,APACHE Ⅱ score of the severe lactic acidosis group were significantly higher than that of high lactate group(P0.01,0.05).But the 28 d mortality has no significant difference.There were no statistically differences in 7 d and 28 d mortality,APACHE Ⅱ score between the high lactate group and the lactic acidosis group.The 7 d and 28 d mortality of the high lactate clearance rate group were significantly lower than that of the low clearance rate group(P0.01).The 28 d mortality of the 24 h low clearance rate group was significantly higher than that of the 24 h secondary clearance rate group(P0.01).The 7 d,28 d mortality of high lactate 8 h group and 24 h group were significantly higher than of the 8 h group(P0.01),and the 28 d mortality was significantly higher than 7 d mortality(P0.05).Conclusion:The overall mortality of 28 d of patients with lactate increase in ICU was significantly high than 7 d.The peak lactate level,lactate clearance rate,high lactate time are good indicators to evaluate patients' prognosis.With the extension of the high lactate time,28 d mortality was significantly higher than 7 d-mortality,blood lactate level fell within normal limits in 8 h may improve the prognosis of critically ill patients.