Correlation of arterial blood lactic acid level in patients with septic shock and mortality 28 days after entering the intensive care unit / 中国医师杂志

ABSTRACT

Objective:To investigate the relationship between the arterial blood lactic acid level after entering the intensive care unit (ICU) and the 28-day mortality of patients with septic shock.Methods:The clinical data of 303 patients with septic shock hospitalized in the department of critical medicine of the Affiliated Hospital of Jining Medical College from April 2015 to June 2019 were analyzed retrospectively. According to the blood lactate (Lac) level, the patients were divided into <4 mmol/L group ( n=203), 4-10 mmol/L group ( n=69) and >10 mmol/L group ( n=31). The baseline characteristics of the patients were analyzed. Multiple logistic regression analysis was used to analyze the independent influencing factors of the 28-day mortality of patients with septic shock. The receiver operating characteristic (ROC) curve was used to analyze the predictive value of the Lac level after entering the ICU for 28-day mortality, and Kaplan-Meier survival curve was performed according to the best cut-off value. Results:A total of 303 patients with septic shock were included, with 179 died in 28 days, and the total mortality was 59.08%. There were 203, 69, 31 patients in Lac<4 mmol/L, 4-10 mmol/L and >10 mmol/L group, respectively. There were significant differences in Acute Physiology and Chronic Health Evalution Ⅱ (APACHE Ⅱ), Sequential Organ Failure Assessment (SOFA), oxygenation index (PaO 2/FiO 2), abdominal infection, the proportion of vasoactive drugs use among the three groups ( P<0.05). Multiple logistic regression analysis showed that the independent influencing factor of the 28-day mortality of septic shock were age, SOFA, use of mechanical ventilation, lactic acid (Lac). ROC curve analysis showed that the area under the ROC curve (AUC) for predicting 28-day mortality of patients with septic shock was 0.604 5 (95% CI 0.540 8-0.668 2). When the optimal cut-off value was 3.55 mmol/L, the sensitivity was 0.508 4, the specificity was 0.733 9, the positive likelihood ratio was 1.910 3 and the negative likelihood ratio was 0.669 9. According to the best cut-off value of entrance Lac, patients were divided into high Lac group (≥3.55 mmol/L) and low Lac group (<3.55 mmol/L), and their 28-day mortality rates were 73.39%(91/124) and 49.16%(88/179). Kaplan-Meier survival curve showed that the 28-day cumulative survival rate of the high Lac group was significantly lower than that of the low Lac group ( P<0.001). Multiple logistic regression analysis showed that after adjusting for confounding factors, the 28 d mortality increased to 1.22 times for each increase of 1 mmol/L of Lac [odds ratio ( OR)=1.22, 95% confidence interval (95% CI) was 1.08-1.37, P=0.001 4]. The 28 d mortality in high Lac group was 3.53 times higher than that in low Lac group ( OR=3.53, 95% CI was 1.36-7.09, P=0.000 4). Conclusions:In patients with ICU septic shock, the arterial blood Lac level after admission was associated with 28-day mortality. Patients with septic shock whose arterial blood Lac level exceeded 3.55 mmol/L within 1 hour of entering the room had a significantly increased risk of death.