To investigate the distribution characteristics of pathogenic bacteria in elderly patients with severe septic shock and the relationship between the state of cardiac function, the change trend of inflammatory factors and the condition of the disease.

A total of 96 elderly patients with severe septic shock who were admitted to Beijing Shijitan Hospital, Capital Medical University from June 2017 to June 2019 were selected as the research objects. According to the prognosis of the patients, they were divided into survival group (n=66) and death group (n=30). Collected and identified the pathogenic bacteria of the patients; detected the cardiac function indicators such as left ventricular end systolic diameter (LVESD), left ventricular end diastolic diameter (LVEDD), and calculated left ventricular ejection fraction (LVEF) after admission. Enzyme-linked immunosorbent assay was used to detect the levels of interlukin-6 (IL-6), C-reactive protein (CRP) and procalcitonin (PCT) in the two groups were collected immediately after admission, 6 and 24 hours after admission. Acute physiology and chronic health score Ⅱ (APACHE-Ⅱ) were performed on patients, and Pearson correlation coefficient analysis was performed on the levels of inflammatory factors IL-6, CRP, PCT and APACHE-Ⅱ. Data were compared with t test, chi-square test or Fisher exact probability method.

A total of 111 strains of pathogenic bacteria were isolated from 96 patients, of which 76 were gram-negative bacteria, accounting for 68.47%, with 27 strains (24.32%) dominated by E. coli; while 32 gram-positive bacteria accounted for 28.83%, with 17 strains by Staphylococcus aureus (15.31%); 3 strains were fungus, accounted for 2.7%. The cardiac function indexes LVESD (40.87±2.04) mm and LVEDD (51.56±1.97) mm of survival group were significantly lower than those of the death group [(42.88±1.77) and (53.78±1.88) mm], and the LVEF 59.54±8.43 was significantly higher than that of the death group (50.33±7.86), the differences between the two groups were statistically significant (t=5.582, 5.190, 5.065; P<0.05). The levels of inflammatory factors IL-6, CRP, PCT and APACHE-Ⅱ scores of patients in the survival group showed a gradual decrease immediately after admission, 6 and 24 hours after admission. The overall comparison of each index at 3 time points showed statistically significance (F=70.375, 563.830, 1 461.640, 236.414; P<0.05); the levels of IL-6, CRP, PCT and APACHE-Ⅱ scores of the death group showed a significant increase over time. The overall comparison of each index at 3 time points showed statistically significant (F=65.059, 549.720, 1 190.989, 173.083; P<0.05); the levels of IL-6, CRP, PCT and APACHE-Ⅱ scores in the survival group at each time point were lower than those in the death group, and the differences were statistically significant (IL-6: t=-4.294, -13.414, -35.499, P<0.05; CRP: t=-10.599, -37.678, -79.754, P<0.05; PCT: t=-28.501, -44.848, -113.978, P<0.05; APACHE-Ⅱ score: t=-9.972, -16.834, -56.426, P<0.05). Pearson correlation analysis between the levels of inflammatory factors IL-6, CRP, PCT and APACHE-Ⅱ score showed that IL-6, CRP, PCT levels were positively correlated with APACHE-Ⅱ score (r=0.674, 0.889, 0.763; P< 0.05).

The distribution of pathogenic bacteria in elderly patients with severe septic shock is mainly gram-negative bacteria. For cardiac function indexes: the lower of the LVESD and LVEDD, the higher the level of LVEF, the better of the prognosis. The levels of inflammatory factors (IL-6, CRP and PCT) are positively correlated with APACHE-Ⅱ score. Dynamic monitoring of inflammatory factors levels can help determine the criticality and prognosis of the patient′s condition and provide evidence for treatment.