[Clinical characteristics and risk factors of early septic patients complicated with bloodstream infection].

OBJECTIVE

To analyze the clinical characteristics, risk factors and prognosis of early septic patients with bloodstream infection (BSI) in department of critical care medicine of Ningxia Medical University General Hospital.

METHODS

Patients with sepsis admitted to department of critical care medicine of Ningxia Medical University General Hospital from November 1, 2019 to August 31, 2021 were included in a prospective observational study. Blood samples were collected for culture within 24 hours of sepsis diagnosis. General information, laboratory test indicators and blood culture results within 24 hours of sepsis diagnosis were recorded. Patients were followed up and prognostic indicators [mechanical ventilation time, length of intensive care unit (ICU) stay, and 28-day survival] were observed. According to blood culture results, patients were divided into BSI group and non-BSI group. Univariate and multivariate Logistic regression analysis were performed on the general clinical characteristics of patients in the two groups to screen the risk factors of early BSI in septic patients. Receiver operator characteristic curve (ROC) was drawn to evaluate the predictive value of risk factors for early BSI in septic patients.

RESULTS

A total of 202 septic patients were included in this study, with 62 patients in BSI group and 140 patients in non-BSI group. The majority of patients in the BSI group were associated with abdominal infection (61.3%), and the majority of patients in the non-BSI group were associated with pulmonary infection (49.3%). A total of 76 strains were isolated from septic patients in BSI group, and the most common pathogens were Escherichia coli (26 strains, 34.2%), Klebsiella pneumoniae (11 strains, 14.4%), Enterococcus (7 strains, 9.2%), Bacteroides fragilis (6 strains, 7.9%) and Staphylococcus aureus (6 strains, 7.9%). There were no significant differences in mechanical ventilation time, the length of ICU stay and 28-day mortality between the BSI group and the non-BSI group. The difference of variables was statistically significant between two group according to Univariate analysis, which included body temperature, acute physiology and chronic health score II (APACHE II), use of antibiotics before admission to ICU, abdominal infection, hypersensitivity C-reactive protein (hs-CRP), serum creatinine (SCr), total bilirubin (TBil), platelet count (PLT), blood lactic acid (Lac) and hypercalcitonin (PCT). Multivariate analysis showed that low PLT [odds ratio (OR) = 1.004, P = 0.019], high Lac (OR = 1.314, P = 0.002), high body temperature (OR = 1.482, P = 0.027), concomitant abdominal infection (OR = 2.354, P = 0.040), no use of antibiotics before admission to ICU (OR = 2.260, P = 0.049) were independent risk factors for early BSI in septic patients. The area under ROC curve (AUC) of PLT, Lac, body temperature, abdominal infection and no use of antibiotics before admission to ICU for predicting early BSI in septic patients were 0.711, 0.686, 0.594, 0.592 and 0.590, respectively. Youden index was used to calculate the optimal cut-off values, which was PLT 122.50×10/L, Lac 2.95 mmol/L, body temperature 39.45 centigrade, respectively. The highest level of AUC was 0.754, the PI guidance group was expected to achieve PI the sensitivity was 75.8%, and the specificity was 68.8%, which were observed when the 5 items were combined.

CONCLUSIONS

Early septic patients with BSI are more serious than those without BSI. Low PLT, high Lac, high temperature, concomitant abdominal infection and no use of antibiotics before admission to ICU are independent risk factors for early BSI in septic patients, and the combination of these five factors has good predictive value.