[The significance of lactic acid in early diagnosis and goal-directed therapy of septic shock patients]

Abstract

Objective: To investigate the application of lactic acid in early diagnosis and goal-directed therapy of septic shock, and to provide reference for the early clinical diagnosis and treatment of septic shock.

Methods: A prospective observational study was conducted, in which patients satisfied with the criteria of septic shock diagnosis were enrolled. The patients were randomly divided into two groups. The lactic group was defined using blood lactic acid concentration < 2 mmol/L as treatment guide target. Control group was defined according to the traditional diagnostic criteria of shock which systolic blood pressure was less than 90 mmHg (1 mmHg= 0.133 kPa) or systolic blood pressure value fell > 40 mmHg baseline or oliguria ( < 0.5 ml. kg-1.h-1) et al traditional septic shock diagnosis criteria and bundle treatment was performed. Organ dysfunction index, the sequential organ failure score (SOFA), acute physiology and chronic health evaluation score II ( APACHE II) score, the time of mechanical ventilation, the time of stay in the intensive care unit ( ICU), and the 7-and 28-day mortality were recorded.

Results: There were 26 and 31 septic shock patients in lactic group and control group respectively. Organ dysfunction index had been improved in different degrees after treatment compared with that before treatment. Creatinine ( Cr) at 48 hours after treatment in lactic group was significantly lower than that in control group (μmol/L: 94.48 ± 6.68 vs. 107.44 ± 10.35, P < 0.05), and there was no statistical difference in other indexes. The SOFA score of lactic group at 24 hours and 48 hours after treatment was lower than that of control group (9.27 ± 4.62 vs. 9.79 ± 3.80, t=2.103, P=0.040; 8.54 ± 5.53 vs. 9.70 ± 4.30, t=2.302, P=0.023). APACHE II score of two group after treatment were lower than that before treatment, and lactic group decreased more obviously compared with control group ( 14.25 ± 5.29 vs. 20.00 ± 9.74, t=2.298, P=0.026; 13.60 ± 6.18 vs 18.15 ± 6.62, t=2.653, P=0.011). The time of stay in the ICU and the time of mechanical ventilation of lactic group were shorter that those of control group, but there was no statistical difference [ICU time (days): 8.95 ± 5.19 vs. 9.45 ± 6.18, t=0.605, P=0.652; mechanical ventilation time (hours): 101.15 ± 11.50 vs. 110.63 ±13.26, t= 0.631, P=0.564]. There was no statistical difference regarding 7-day mortality of lactic group was lower than that of control group [15.38% (4/26) vs. 16.13% ( 5/31), Χ2=0.000, P=1.000]. The 28-day mortality of lactic group was lower than that of control group [26.92 % (7/26) vs. 54.84% (17/31). Χ2=4.520, P=0.033].

Conclusion: By blood lactic acid monitoring, inadequacy of organization perfusion i.e. septic shock can be found in the early stage, thus early intervention can be performed and improve resuscitation result and reduce the mortality of septic shock patients. Blood lactic acid ≥ 4 mmol/L can be used as one of the criteria for the diagnosis of septic shock, and 6-hour blood lactic acid < 2 mmol/L as a goal to guide shock treatment with obvious prognosis improvement.