COLONIZATION WITH ANTIBIOTIC-RESISTANT GRAM-NEGATIVE ORGANISMS IN A PEDIATRIC INTENSIVE-CARE UNIT

Objective: To measure the prevalence of colonization with antibiotic-r esistant Gram negative organisms and its association with potential ri sk factors, including antibiotic exposure, in a pediatric intensive ca re unit (ICU). Design: Prospective, observational study, Setting: A 16 -bed tertiary care pediatric ICU. Patients: AII children admitted to t he pediatric ICU for >24 hrs over a 5-month period, Measurements and M ain Results: Two hundred ninety six patients, approximately half of al l patients admitted to the ICU, were enrolled in the study; 236 patien ts had sufficient data collected for analysis and were prospectively e xamined for nasopharyngeal and gastrointestinal colonization by antibi otic-resistant Gramnegative organisms (ceftazidime minimal inhibitory concentration of >16 mu g/mL, or tobramycin minimal inhibitory concent ration >8 mu g/mL). Association between colonization and potential pre disposing factors including demographics, diagnosis, Pediatric Risk of Mortality (PRISM) score, invasive instrumentation, and prior ICU anti biotic exposure was assessed. More than 20% of patients were found to be colonized with an antibiotic-resistant Gramnegative organism. Exami nation of the timing of colonization indicated that more than half wer e identified within 72 hrs of admission, Colonization was associated b y unadjusted analysis to prior ICU antibiotic exposure, as well as by factors associated with the severity of illness (PRISM score and invas ive instrumentation) and young age, However, when the independence of these factors was tested by logistic regression, prior antibiotic expo sure was no longer associated with resistant organism colonization, Co nclusions: These data suggest that antibiotic-resistant Gram-negative organisms are a significant risk to intensively iii children and that in many instances, they are imported into the unit or rapidly acquired from environmental reservoirs, Since risk factors for colonization ar e multiple, policies confined to antibiotic utilization within the ICU may have fixed, and possibly limited, benefit in their control.