[Combined prognostic value of serum lactic acid, procalcitonin and severity score for short-term prognosis of septic shock patients]

Abstract

Objective: To explore the value of lactic acid (Lac), procalcitonin (PCT), sequential organ failure assessment (SOFA) score and acute physiology and chronic health evaluation II (APACHE II) score in assessing the severity and predicting the prognosis in sepsis shock.

Methods: A retrospectively study was conducted. Patients with septic shock hospitalized in the department of critical care medicine of the Affiliated Hospital of Jining Medical University from April 2015 to June 2019 were enrrolled. The patient's gender, age, body mass index (BMI), infection site, organ dysfunction status; Lac, PCT, C-reactive protein (CRP), heart rate and body temperature immediately after admission to the intensive care unit (ICU); APACHE II and SOFA scores within 24 hours, and 28-day prognosis were collected. According to the 28-day prognosis, the patients with septic shock were divided into the survival group and the death group, and the differences in the indicators between the groups were compared. Multivariate Logistic regression analysis was used to screen the risk factors of 28-day death in patients with septic shock; receiver operating characteristic curve (ROC curve) was used to analyze the value of Lac, PCT, SOFA, APACHE II, and age in predicting the 28-day prognosis of patients with septic shock.

Results: A total of 303 septic shock patients were enrolled, of which 124 cases survived and 179 died on the 28th day, and the 28-day mortality was 59.08%. (1) Compared with the survival group, patients in the death group were older (years old: 66.58±15.22 vs. 61.15±15.68), APACHE II, SOFA, proportion of lung infections, Lac increased [APACHE II score: 22.79±7.62 vs. 17.98±6.88, SOFA score: 9.42±3.51 vs. 5.65±1.59, proportion of lung infections: 53.63% (96/179) vs. 39.52% (49/124), Lac (mmol/L): 5.10±3.72 vs. 3.71±2.56], oxygenation index (PaO₂/FiO₂) and ICU body temperature decreased [PaO₂/FiO₂ (mmHg, 1 mmHg = 0.133 kPa): 198.94±80.15 vs. 220.68±72.06, ICU body temperature (centigrade): 37.47±1.08 vs. 37.80±1.14], and the differences were statistically significant (all P < 0.05). (2) Multivariate Logistic regression analysis results: after adjusted for potential confounding factors, APACHE II, PCT, Lac, age and SOFA were independent risk factors for death in patients with septic shock [APACHE II: odds ratio (OR) =1.05, 95% confidence interval (95%CI) was 1.01-1.10, P = 0.039; PCT: OR = 0.99, 95%CI was 0.98-1.00, P =0.012; Lac: OR = 1.23, 95%CI was 1.08-1.40, P = 0.002; age: OR = 1.03, 95%CI was 1.01-1.05, P = 0.009; SOFA score: OR =1.88, 95%CI was 1.59-2.22, P < 0.001]. (3) ROC curve analysis showed that APACHE II, Lac, age and SOFA could predict the prognosis of patients with septic shock [APACHE II: the area under the ROC curve (AUC) = 0.682 4, 95%CI was 0.621 7-0.743 1, P = 0.000; when the best cut-off value was 18.500, its sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio and negative likelihood ratio were 72.63%, 54.84%, 69.89%, 58.12%, 1.608 1 and 0.499 2, respectively. Lac: AUC = 0.604 5, 95%CI was 0.540 8-0.668 2, P = 0.002; when the best cut-off value was 3.550 mmol/L, the sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio and negative likelihood ratio were 50.84%, 73.39%, 73.39%, 50.94%, 1.910 3 and 0.669 9, respectively. Age: AUC = 0.599 1, 95%CI was 0.535 4-0.662 7, P = 0.003; when the best cut-off value was 72.500 years old, the sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio and negative likelihood ratio were 42.46%, 75.00%, 71.03%, 47.45%, 1.698 3 and 0.767 2, respectively. SOFA: AUC = 0.822 3, 95%CI was 0.776 7-0.867 9, P = 0.000; when the best cut-off value was 7.500, its sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio and negative likelihood ratio were 68.72%, 87.90%, 89.13%, 66.06%, 5.680 4, 0.355 9 respectively]. The combined prediction had a good sensitivity (72.63%) and specificity (84.86%), and AUC (0.876 5) was higher than that of a single variable, suggested that the multivariate combination was more accurate in predicting the short-term outcome of septic shock.

Conclusions: Lac, PCT, SOFA score, APACHE II score and age were independent risk factors for death in patients with septic shock, and the accuracy of Lac, SOFA score, APACHE II score and age in predicting short-term prognosis of septic shock was better than that of single variable, and the diagnostic value was higher.