ABSTRACT
Objective To analyze the pathogenesis and clinical characteristics of blood stream infection (BSI) occurring after chemotherapy in elderly patients with hematological malignancies hospitalized in this hospital, and to evaluate the role of procalcitonin (PCT) level in judging the pathogenic type of bacteria in BSI. Methods Thirty-nine elderly patients with malignant hematopathy were admitted to the Department of Hematologic Oncology of Shanxi Province Coal Center Hospital from June 2015 to June 2017, after admission they were treated with chemotherapy, then they were complicated with blood stream infection, and their clinical data were retrospectively analyzed; the clinical efficacy, the pathogenic factor of BSI occurring during chemotherapy, infection sites, pathogenesis, the different levels of PCT of bacterial types in BSI, etc. were observed. Results Thirty-nine cases of BSI were all in the stage of agranulocytosis, the proportion of relapsed and refractory re-induction remission chemotherapy was significantly higher than that of initial induction remission and consolidation intensive therapy [51.3% (20/39) vs. 28.2% (11/39), 20.5% (8/39)]. The BSI in 29 patients was controlled and 10 cases with BSI were dead. Clear infection sites sequences were respiratory tract (37 case times), digestive tract (25 case times) and anus periphery (10 case times); 39 pathogenic strains were isolated from the blood cultures, including the gram positive (G+) bacteria accounting for 43.6% (17/39), gram negative (G-) bacteria 53.8% (21/39) and fungi 2.6% (1/39). At the high level of PCT, the detection rate of G- bacteria was high, the PCT levels of isolated G- bacteria such as Escherichia coli, Aerobacter cloacae, Pseudomonas aeruginosa, Klebsiella pneumoniae, Acinetobacter bauman from high to low in turn were 12.82 (9.91 - 15.73), 10.19 (7.17 - 12.21), 10.01 (7.85 - 12.28), 9.68 (7.95 - 11.41), 8.12 (7.12 - 9.12) μg/L respectively; at the low level of PCT, the detection rate of G+bacteria was high, PCT levels of isolated G+bacteria such as methicillin-resistant Staphylococcus aureus, Enterococcus faecium, Streptococcus pneumoniae, Hemolytic streptococcus from high to low in turn were 6.87 (4.12 - 9.62), 2.78 (2.17 - 3.39), 1.31 (0.42 - 2.20), 1.05 (0.39 - 1.71) μg/L respectively. The positive predictive value of PCT for the diagnosis of G- bacterial BSI was higher than that for the G+bacterial BSI (90.1% vs. 78.3%). Conclusions In elderly patients with hematological malignancies, after chemotherapy, they are accompanied by BSI that is closely related to granulocyte count; PCT level has a suggestive effect on different types of bacteria as pathogen of BSI and the high level of PCT indicates a greater possibility that the BSI is due to G- bacterial infection.