PI-04. Bloodstream infections in pediatric patients with CVCs after allogeneic HSCT: incidence, risk factors and outcome

Summary

Bloodstream infection is a serious, life-threatening complication in neutropenic patients early after allogeneic HSCT and can lead to dramatic consequences such as a septic shock, multiple organ failure, and death. Bacteremia is associated primarily with installation of central venous catheter (CVC). The risks of CVC infection (CI) with development of bacteremia in HSC recipients can reach 20 to 40% during the period of neutropenia, before reconstitution of neutrophils. The CVC placement just before beginning of the conditioning regimen (RC) for long-term infusion therapy, parenteral nutrition and antibiotic therapy. The aim of our study was to assess incidence of CI, appropriate risk factors, frequency of pathogen verification, to identification of main causative agents and outcome of CI episodes in the patients with malignant oncohematological diseases during early period after allogeneic HSCT.

Materials and methods

The study included a retrospective analysis of 61 CI cases with subsequent CVC replacement in 52 patients from 0 to 30 days after allo-HSCT over the period of 2019 to 2021. In 2019, the incidence of bloodstream infection (CI) was 26.7% (n=15); in 2020, 35.2% (n=30), and in 2021, 31.3% (n=16). The patients were diagnosed with AML (n=18), ALL (n=28), MDS/JMML (n=6). The median age of patients at the time of BMT was 7 years (0.4 months to 17 years). The main factors of observation were as follows: duration of the CVC placement, number of CVC installed, punctured vein, duration of febrile neutropenia (FN), the number of cultures during the FN period, frequency of pathogen detection, types of infectious agents seeded from blood and CVC, presence of mucositis, and its severity, transfer of the patient to intensive care unit, as well as outcomes of systemic inflammatory response (SIRS) episodes associated with CVC.

Results

CVC-associated bloodstream infections (CI) developed at a median of 13 days after HSCT, with CVC placement terms of 22 days. The median duration of FN before the change of CVC was 72 hours. Bacteriological cultures were performed in BD BACTEC vials, with a median number of 6 culture samples (1 to 25) per a single FN episode. Upon analyzing results of bacteriological cultures from blood and CVC, the frequency of pathogen detection in blood in absence of seeding from CVC was found in 42.6%. Positive cultures both from blood and CVC were revealed in 14.7%. Positive blood cultures in presence of pathogens from CVC were registered in 6.5%, whereas no pathogens in blood or CVC were detected in 36% of cases. Staphylococcus epidermidis (n=19) and Klebsiella pneumoniae (n=10) were identified as the most common pathogens in CVC-associated infections. Gram-positive bacteria were more common in blood and CVC cultures than Gram-negative microbes (n=18 and n=13, respectively). Mixed bacterial flora was identified in 8 cases. Clinically significant gastrointestinal mucositis was observed in 39 patients. There were 56 CI episodes which ended in body temperature normalization following CVC removal, and timely administration of antibiotic therapy. In 9 cases, the patients were transferred to intensive care unit, and two deaths were registered.

Conclusion

Special features of managing the patients with febrile neutropenia after allogeneic HSCT include timely antibiotic therapy and evaluation of clinical response. In cases of lacking clinical response and suspected septicemia, CVC removal is required, even in absence of verifiable pathogens. This feature prolongs the time interval before CVC change, which subsequently leads to an unfavorable outcome. The priority task for nursing staff is to prevent the CVC-associated infections by following principles of aseptics and antiseptics when handling CVCs, as well as timely exchange of infusion systems and careful maintenance of the catheter entry site.

Keywords

Central venous catheter, bloodstream infection, sepsis, nursing care.