Diagnosis of catheter-related bloodstream infections among pediatric oncology patients lacking a peripheral culture, using differential time to detection.
BACKGROUND
Current methods for in situ diagnosis of catheter-related bloodstream infections require concurrent collection of central venous catheter (CVC) and peripheral vein (PV) blood cultures. Both the pain and inconvenience of PV cultures are undesirable.


METHODS
A prospective study was conducted (August 2002 to March 2004) to assess the accuracy of diagnosing catheter-related bloodstream infections based on the difference in time to detection of blood cultures drawn concurrently from 2 lumens of a multilumen CVC. This difference in time to detection between 2 lumens was compared with results of the standard criterion with paired CVC and PV blood cultures.


RESULTS
Twenty-one infectious episodes were categorized as catheter-related bloodstream infections and 38 as non-catheter-related bloodstream infections. With a cutoff in difference in time to detection between 2 lumens of > or =180 minutes, the sensitivity of this test to diagnose a catheter-related bloodstream infection was 61% (95% confidence interval, 39-80%) and the specificity was 94% (95% confidence interval, 82-99%). In 4 of 7 episodes with false-negative results, the colony counts in cultures from both lumens were >400 colony-forming units/mL (maximal value reported), indicating the limitation of this method when both lumens of the catheter are colonized. With the pretest probability of catheter-related bloodstream infections ranging from 28% to 54%, the positive predictive value of a difference in time to detection between 2 lumens of > or =180 minutes for diagnosis of catheter-related bloodstream infections ranged from 81% to 93% and the negative predictive value ranged from 67% to 86%.


CONCLUSIONS
Within the context of its limitations, this novel method provides an alternative for diagnosing catheter-related bloodstream infections among patients with a CVC, without PV cultures.
Gaur
Aditya H
AH
Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, TN 38105-2794, USA. aditya.gaur@stjude.org
Flynn
Patricia M
PM
Heine
Daniel J
DJ
Giannini
Mary Anne
MA
Shenep
Jerry L
JL
Hayden
Randall T
RT
D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage; D016470:Bacteremia / Q000175:diagnosis / Q000209:etiology*; D001431:Bacteriological Techniques; D001769:Blood / Q000382:microbiology*; D017848:Blood-Borne Pathogens / Q000302:isolation & purification*; D002405:Catheterization, Central Venous / Q000009:adverse effects*; D002648:Child; D002675:Child, Preschool; D004866:Equipment Contamination; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D009369:Neoplasms / Q000175:diagnosis / Q000188:drug therapy*; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013997:Time Factors