OBJECTIVE

To investigate the relationship between serum cholinesterase (SChE) level and the prognosis of patients with septic shock (SS).

METHODS

A total of 594 patients with SS admitted to the First Affiliated Hospital of Zhengzhou University from June 2013 to June 2017 were enrolled. General data such as gender, age, acute physiology and chronic health evaluation II (APACHE II) score were recorded as well as routine blood test, procalcitonin (PCT), hepatic function, renal function, coagulation function and blood gas analysis parameters within 48 hours of SS diagnosis. The patients were followed by telephone from September to October in 2019, and the outcome was recorded. The primary outcome was all-cause death 28 days after discharge. The secondary outcomes were all-cause death in intensive care unit (ICU) and 2 years after discharge, and the length of ICU stay. The patients were divided into two groups according to prognosis of 28 days: the survival group and the death group. The clinical data of the two groups were compared. Multivariate Cox regression analysis was used to screen prognostic risk factors of 28 days in patients with SS. The receiver operating characteristic (ROC) curve was used to explore predictive value of liver function parameter SChE for 28-day prognosis of patients with SS. The patients were divided into two groups according to the levels of SChE: the low SChE group (SChE ≤ 4 000 U/L) and the normal SChE group (SChE > 4 000 U/L). Kaplan-Meier survival curves were used to compare the cumulative survival rates without endpoint event of patients with different SChE levels.

RESULTS

A total of 385 patients with SS were enrolled according to the inclusion and exclusion criteria, and a total of 356 patients were followed up successfully, with a follow-up rate of 92.5% (356/385). There were 142 survival patients and 214 death patients at 28 days, with a 28-day mortality rate of 60.1% (214/356). There were 116 survival patients and 240 death patients at 2 years, with a 2-year mortality rate of 67.4% (240/356). Compared with the 28-day survival group, the patients in the death group were older and had higher APACHE II score, partial hepatic and renal function parameters, higher level of blood lactate (Lac) and lower levels of white blood cell count (WBC), platelet count (PLT) and SChE with statistically significant differences. Multivariate Cox regression analysis showed that the age [relative risk (RR) = 1.444, 95% confidence interval (95%CI) was 1.090-1.914, P = 0.010], APACHE II score (RR = 2.249, 95%CI was 1.688-2.997, P = 0.000), SChE (RR = 1.469, 95%CI was 1.057-2.043, P = 0.022), and Lac (RR = 2.190, 95%CI was 1.636-2.931, P = 0.000) were independent risk factors for 28-day mortality of patients with SS. The ROC curve analysis showed that SChE had a weak prognostic value for 28-day prognosis of patients with SS [the area under ROC curve (AUC) was 0.574]. However, the combined predictive value of SChE, APACHE II score and Lac was greater than APACHE II score or Lac alone for prediction (AUC: 0.807 vs. 0.785, 0.697), with a sensitivity of 79.9% and a specificity of 68.5%. Compared with the normal SChE group (n = 88), the 28-day mortality of patients in the low SChE group (n = 268) was significantly increased [63.1% (169/268) vs. 51.1% (45/88), P < 0.05], but ICU mortality [59.7% (160/268) vs. 48.9% (43/88)], 2-year mortality [69.8% (187/268) vs. 60.2% (53/88)] or the length of ICU stay [days: 4 (2, 7) vs. 5 (2, 9)] between the two groups showed no statistical significance (all P > 0.05). Kaplan-Meier survival curve analysis showed that the cumulative survival rate without endpoint event of patients in the low SChE group was significantly lower than that in the normal SChE group (Log-Rank test: χ = 5.852, P = 0.016).

CONCLUSIONS

Increased risk of 28-day mortality in patients with SS whose SChE is below normal. The level of SChE is an independent risk factor for 28-day death in SS patients, and it is one of the indicators to evaluate the short-term prognosis of patients with SS.