Failure of systemic antibiotics to eradicate gram-negative bacilli from the airway of mechanically ventilated very low-birth-weight infants.
BACKGROUND
Gram-negative bacillary (GNB) airway colonization in mechanically ventilated newborns is associated with morbidity and mortality, which may be reduced if systemic antimicrobial therapy eradicates GNB from the airway. Efforts to do so in adults have met with variable success; similar experiences in newborns have not been reported.


METHODS
From 1991 through 1998, 531 very low-birth-weight infants were mechanically ventilated longer than 2 weeks. The study group was 106 infants with GNB airway colonization. Sixty-four other neonates in whom GNB nosocomial bloodstream infections developed served as antibiotic treatment outcome control.


RESULTS
Isolated from the airway were enteric (70 cases) and environmental (36 cases) GNB. Gentamicin alone or with ceftazidime (79), ceftazidime (11), piperacillin in combination with tazobactam or tobramycin (8), and tobramycin, in combination with ampicillin/sulbactam or mezlocillin (8) were the antimicrobials selected. Systemic antibiotics failed to eradicate GNB colonization in 97% of the cases. Six of the 106 infants with airway colonization died for reasons unrelated to infection. Sixty-four infants experienced 67 bloodstream infections as a result of enteric (53) and environmental (14) GNB. Gentamicin alone (23), with ceftazidime (26), or with clindamycin or ampicillin/sulbactam (9), piperacillin with tazobactam or tobramycin (3) and ceftazidime alone (6) were the antimicrobials selected. Survival occurred in 84% of the 67 nosocomial bloodstream infections.


CONCLUSIONS
Systemic antibiotics do not consistently eradicate GNB from the airway of mechanically ventilated newborns, therefore its empirical use for prophylaxis or treatment of airway colonization should be discouraged.
Newborn Services, the Department of Pediatrics, The Ohio State University Medical Center, Columbus, OH 43210-1228, USA.
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Cordero
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Sananes
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Ayers
D000046:Academic Medical Centers; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D019072:Antibiotic Prophylaxis; D000075202:Contraindications; D003428:Cross Infection / Q000097:blood / Q000188:drug therapy* / Q000453:epidemiology; D005260:Female; D006090:Gram-Negative Bacteria / Q000187:drug effects / Q000302:isolation & purification*; D016905:Gram-Negative Bacterial Infections / Q000188:drug therapy* / Q000453:epidemiology; D006801:Humans; D007231:Infant, Newborn; D019102:Infant, Very Low Birth Weight; D007363:Intensive Care Units, Neonatal; D008297:Male; D009820:Ohio / Q000453:epidemiology; D012121:Respiration, Artificial; D012189:Retrospective Studies; D017211:Treatment Failure
D000900:Anti-Bacterial Agents