Systemic antibiotics fail to clear multidrug-resistant Klebsiella from a pediatric ICU

STUDY OBJECTIVEs: To determine the magnitude of infection rate and antimicrobial resistance in a pediatric ICU (PICU), and to evaluate the efficacy of using broad-spectrum antibiotics. DESIGN: A 3-month, prospective, observational cohort audit. SETTING: A 12-bed tertiary, referral PICU. PATIENTS OR PARTICIPANTS: All children admitted to the PICU for > 72 h. INTERVENTIONS: Surveillance cultures of throat and rectum on admission and once weekly thereafter. MEASUREMENTS AND RESULTS: Of the 150 admissions during the 3-month period, a total of 52 patients (24 girls and 28 boys) requiring mechanical ventilation for a minimum of 3 days were enrolled in the audit. The median age and interquartile range (IQR) was 17 months (IQR, 5.8 to 63); length of stay, 6.5 days (IQR, 4 to 13); ventilation days, 5 (IQR, 3 to 11); pediatric risk of mortality score, 14 (IQR, 9 to 19); and risk of mortality, 0.03 (IQR, 0.014 to 0.087). Fifteen patients (29%) developed 21 infections, mainly lower-airway infections and septicemias. Of the 52 children, 7 children carried multidrug-resistant bacteria and 3 patients progressed to develop four infections with those resistant bacteria. Of the seven carriers, six patients carried gentamicin-resistant Klebsiella. Methicillin-resistant Staphylococcus aureus, penicillin-resistant Streptococcus pneumoniae and gentamicin-resistant Pseudomonas aeruginosa each were carried by one child. Six of those nine resistant isolates were present in the admission flora. Despite the potent combination of piperacillin/tazobactam and amikacin, three children acquired the multidrug-resistant Klebsiella while in the PICU and became nosocomial carriers. CONCLUSIONS: Only surveillance cultures allow the distinction between import of multidrug-resistance and resistant bacteria acquired while in PICU. In this study, two thirds of the resistant isolates were imported. The introduction of newer potent systemic antibiotic combinations failed to control the endemic reservoir of multidrug-resistant Klebsiella and suggests that such policies have little impact.