Evaluation of febrile neutropenia episodes in patients with hematologic malignancies

Purpose: Febrile neutropenia is a hematologic emergency that is frequently encountered in immunocompromised patients or during chemotherapy and requires early diagnosis and treatment. The clinical course and characteristics of FEN attacks should be evaluated at regular intervals and studies examining the efficacy of treatment should be conducted. The aim of this study was to investigate the clinical and laboratory findings and treatments administered in pediatric patients who were followed up in our hospital due to hematologic malignancy and had FEN attacks and to document the data of our center. Materials and Methods: FEN episodes of patients who were followed up with a diagnosis of hematologic malignancy in the Pediatric Hematology Clinic of Manisa Celal Bayar University Faculty of Medicine Hospital between 2014 and 2021 were evaluated. In this study; age, gender, neutrophil count, number of FEN attacks, complaints accompanying fever, type of infection, duration of fever, duration of fever, part of the treatment, culture results and antibiotics used in FEN attacks were investigated retrospectively. Findings: In our study, 148 FEN episodes of 42 patients were retrospectively analyzed. Of the patients, 34 had ALL, six had AML and two had JMML. Neutrophil count was <500/mm3 in 118, 500-1000/mm3 in 24 and 1000-1500/mm3 in six of the FEN episodes. Of the febrile neutropenia episodes, 53 (35.8%) were in female patients and 95 (64.2%) in male patients. When the recovery time of neutropenia in patients with acute lymphoblastic leukemia was analyzed according to risk groups, it was found to be 9 days ± 6.16 days in SRG, 8.79 days ± 9 days in MRI, and 14.35 days ±11.15 days in HRG. The prolonged duration of neutropenia in patients in the high-risk group was statistically significant (p:0.019). Cough was the most common complaint in 40 episodes (27%), while 61 episodes (41.2%) were asymptomatic. When the distribution of infection clinics was analyzed, URTI clinic was the most common clinic with 35 episodes (40.2%). While growth was detected in blood cultures in 42 (28.3%) of febrile neutropenia episodes, no growth was detected in 106 (71.6%). In patients with acute lymphoblastic leukemia, FEN episodes were most commonly seen in the consolidation (48 episodes, 42.9%) and induction phase (26 episodes, 23.2%), while in patients with acute myeloid leukemia, AIE (10 episodes, 31.25%) and HAE (eight episodes, 25%) were most commonly seen in the treatment block. When the antibiotics started on the first day of EN attacks were analyzed, it was found that meropenem monotherapy was started in only 4.7% of the attacks, while combined treatment was started in 95.3%. Discussion and Conclusion: FEN in patients with hematologic malignancies leads to prolonged hospitalization, increased need for broad-spectrum antibiotics, decreased quality of life and mortality. There has been a significant reduction in mortality due to empirical antibiotic use in patients with febrile neutropenia. In patients with hematologic malignancies, neutropenia duration >10 days and ANS <100 mm3 are the most important factors that increase the risk of infection. In our study, 53.3% (79 episodes) of patients had ANS<100 mm3 and 35.8% (53 episodes) had neutropenia duration of more than 10 days. Although the duration of neutropenia was significantly longer in high-risk patients than in low- and intermediate-risk patients, the number of FEN episodes per patient was similar. The most valuable indicator of microbiologically proven infection in febrile neutropenia episodes is the demonstration of growth of the causative pathogen in culture. The frequency of bacteremia is reported to be 20-46.5% in the literature. In our study, consistent with the literature, 26.3% (39 episodes) of FEN episodes showed growth in blood culture. The most common bacterium produced in blood cultures was CNS (24 episodes, 57%), while the bacterium with the highest antibiotic resistance was Klebsiella pneumonia (7 episodes, 16,6%). Growth was detected in 11 (12.3%) of 89 urine cultures. Escherichia coli was the most common microorganism grown in the cultures (45.4%). Bone marrow suppression is different according to the chemotherapy protocols that patients with hematologic malignancies are receiving during the FEN attack. In our study, the risk of FEN was found to be higher in induction and consolidation treatment of AL, and this was attributed to the more pronounced bone marrow suppression during these periods of treatment.