Factors that can interfere in the result of blood culture in pediatric intensive care unit

Abstract

OBJECTIVE: To analyze factors that can interfere with the results of blood culture in a pediatric population, as there are few reports of standardization of blood culture in Pediatrics. METHODS: During three months 100 blood samples, collected at the Pediatric Intensive Care Unit of the "Hospital das Clínicas" of the Medical School of the Campinas State University (UNICAMP) were analyzed with respect to site and manner of collecting, age of the patients, clinical diagnosis, type of antiseptic substance used and blood volume withdrawn for sample. RESULTS: Two samples were sufficient to diagnose bacteremia. The positivity of the samples were related to the age of the patients. The rate of contamination related to the total number of samples was of 5%. All the false-positive samples were collected from children less than one year of age. The blood culture diagnosed bacteremia by multiresistant agents even in patients using antibiotics. CONCLUSIONS: The contamination of the samples (false-positives) was related with the age of the children, probably with the difficulty to obtain the blood. The interference of the antibiotics were demonstrated, specially in Pediatric Intensive Care Unit. Blood culture was useful to identify multiresistant agents in children receiving broad spectrum antibiotics. Because of the importance of blood culture and the knowledge of factors that can interfere with the results, one should be critical regarding indication and way of collecting the exam in order to avoid iatrogenic problems to the patients.