The Research Of Value Of Serum Procalcitonin Detection Combined With Faecal Flora Analysis In Determining The Etiology Of Nosocomial Infection

OBJECTIVE:To analyze the clinical value of serum procalcitonin(PCT)combined with the intestinal microbiota composition for the early diagnosis of gram-negative(G~-)bacteria and gram-positive(G~+)bacteria in ICU patients with nosocomial infection.METHODS:From December 2015 to December 2018,the clinical data of 110 patients with nosocomial infection in ICU was analyzed.And the patients were divided into the G~+bacterial group(47 cases)and the G~-bacterial group(63 cases).The infection site and etiological distribution of the two groups were compared;The efficacy of empirical antimicrobial therapy was compared between the two groups;The clinical data,serum PCT concentration and the intestinal microbiota composition of the two groups were compared.According to the analysis of ROC curve,the optimal diagnostic values of serum PCT and the intestinal microbiota composition for the diagnosis of pathogens were determined.RESULTS:1.In this experiment,110 patients were included,including 90 cases with respiratory tract infection and 14 cases with bloodstream infection,Distribution of etiology in pulmonary infection:55 cases with G-bacteria and 35 cases with G+bacteria;Distribution of etiology in bloodstream infection:8 cases with G+bacteria and6 cases with G-bacteria.2.The effective rate of empirical antibacterial treatment was46.03%(29/63)in the g-bacteria group and 36.17%(17/47)in the G+bacteria group,but the comparison between the two groups was not statistically significant(p=0.30).3.Compared with the patients in the G~+bacterial group,the PCT concentration,blood glucose,heart rate,the score of SIRS and APACHEⅡof patients in G~-bacterial group were higher(P<0.05).And the ratio of fecal G~-bacteria to G~+bacteria was higher in G~-bacterial group(P<0.01).When the diagnostic cut-off point was PCT≥1.02 g/L,the area under the curve(AUC)was 0.82(0.74～0.90),the sensitivity was 73.02%.When the diagnostic cut-off point was the ratio of fecal G~-bacteria to G~+bacteria≥3,the area under the curve(AUC)was 0.81(0.73～0.89),the sensitivity was 63.49%.The sensitivity of PCT combined with the gut microbiota composition for diagnosing G~-bacteria was82.54%,which was higher than that of PCT or fecal flora analysis alone(P<0.01).CONCLUSION:1.Nosocomial infection mainly includes respiratory tract infection and blood stream infection,which is of guiding value for severe patients to strengthen the protection of susceptible sites and select sensitive antibiotics for treatment.2.When serious patients suffer from nosocomial infection,the effectiveness of empirical antibacterial treatment is not ideal at present,especially for G+bacterial infection.3.The serum PCT combined with the gut microbiota composition had the high sensitivity and accuracy for diagnosing pathogens of the patients with nosocomial infection in ICU.It is worthy of clinical application.