Antibiotic restriction does not alter endemic colonization with resistant gram-negative rods in a pediatric intensive care unit.
OBJECTIVE
To test whether a ceftazidime restriction policy in a pediatric intensive care unit (ICU) could decrease the endemic rate of colonization with ceftazidime-resistant gram-negative bacilli.


METHODS
Prospective, pre- vs. postintervention study.


METHODS
University hospital pediatric ICU.


METHODS
Consecutive children admitted to the pediatric ICU over a 19-mo period.


METHODS
After an observation period in which antibiotic use was not controlled, ceftazidime was prohibited unless the patient's microbiological results indicated that the drug was necessary for cure. Aminoglycoside use was not regulated. The size of the endemic reservoir of ceftazidime- and tobramycin-resistant organisms was determined by daily nasopharyngeal and rectal swab specimens obtained on all admissions to the ICU.


RESULTS
Despite a 96% reduction in ceftazidime use, the incidence density (number of isolates/100 patient-days) of ceftazidime-resistant organisms increased through the course of the study, from 1.57 to 2.16. The incidence density of tobramycin-resistant organisms was unchanged. Ceftazidime restriction resulted in a small but nonsignificant decrease in the proportion of ceftazidime-resistant organisms acquired late (beyond 72 hrs) in the patients' ICU course (56.5% vs. 45.9%). However, there was a more substantial decrease in the proportion of ceftazidime-resistant organisms derived from species known to harbor derepressible amp C beta-lactamases (68.2% vs. 45.9%, p < .05).


CONCLUSIONS
These data indicate that antibiotic restriction policies in an ICU fail to diminish the size of the endemic reservoir of antibiotic-resistant gram-negative rods, and suggest that such policies in the absence of broader efforts to limit antibiotic use will have little impact.
Toltzis
P
P
Department of Pediatrics, Case Western Reserve University School of Medicine, Cleveland, OH, USA. pxt2@po.cwru.edu
Yamashita
T
T
Vilt
L
L
Green
M
M
Morrissey
A
A
Spinner-Block
S
S
Blumer
J
J
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002442:Ceftazidime / Q000494:pharmacology; D018550:Cephalosporin Resistance; D002511:Cephalosporins / Q000494:pharmacology; D016009:Chi-Square Distribution; D002648:Child; D000075202:Contraindications; D004305:Dose-Response Relationship, Drug; D004352:Drug Resistance, Microbial; D006090:Gram-Negative Bacteria / Q000187:drug effects* / Q000302:isolation & purification; D006801:Humans; D015278:Intensive Care Units, Pediatric; D008826:Microbial Sensitivity Tests / Q000379:methods / Q000706:statistics & numerical data; D009305:Nasopharynx / Q000382:microbiology; D012007:Rectum / Q000382:microbiology; D013997:Time Factors; D014031:Tobramycin / Q000494:pharmacology
D000900:Anti-Bacterial Agents; D002511:Cephalosporins; D002442:Ceftazidime; D014031:Tobramycin