Objective To explore the values of the Simplified Acute Physiology Score Ⅱ (SAPS-Ⅱ), serum procalcitonin (PCT) and lactate clearance rate (LCR) in predicting the prognosis of patients with septic shock.

Methods The clinical materials of 127 patients with septic shock were analyzed, and the patients were divided into death group and survival group according to the prognosis. The SAPS-Ⅱ, serum PCT and LCR were compared between the two groups; a multivariate Logistic regression model was used to analyze the relevant factors affecting prognosis of patients; the receiver operating characteristic (ROC) curve was used to analyze the values of the above factors in predicting prognosis.

Results In the 127 patients with septic shock, 45 cases died within 28 days, with a mortality rate of 35.43% (45/127); the SAPS-Ⅱ score, PCT levels at admission and 48 hours after admission, and blood lactate levels at admission and 6 and 48 hours after admission in the death group were significantly higher than those in the survival group, while the oxygenation index and LCR at 6 and 48 hours after admission were significantly lower than those in the survival group (P < 0.05). The multivariate Logistic regression analysis showed that SAPS-Ⅱ score, PCT at admission, PCT at 48 h after admission, blood lactate at admission, blood lactate at 6 h after admission, and blood lactate at 48 h after admission were the risk factors for the prognosis of patients with septic shock (P < 0.05), while oxygenation index, LCR at 6 h after admission, and LCR at 48 h after admission were the protective factors for the prognosis of patients with septic shock (P < 0.05). ROC curve analysis showed that the sensitivities and the area under the curve (AUC) values of SAPS-Ⅱ score combined with PCT at admission and LCR at 6 h after admission as well as SAPS-Ⅱ score combined with PCT at 48 h after admission and LCR at 48 h after admission in predicting the prognosis of patients with septic shock were 95.56%, 0.922 and 97.78%, 0.926 respectively, which were significantly higher than the those predicted by single indicator (P < 0.05).

Conclusion The SAPS-Ⅱ score, PCT at admission, PCT at 48 h after admission, LCR at 6 h after admission and LCR at 48 h after admission are the factors affecting the prognosis of patients with septic shock. Moreover, the combination of SAPS-Ⅱ score with serum PCT and LCR at different time points can improve the predictive value of prognosis for these patients in clinical practice, especially the combination of SAPS-Ⅱ score and serum indicators at 48 h after admission has a higher predictive value.