Difference in time to positivity of hub-blood versus nonhub-blood cultures is not useful for the diagnosis of catheter-related bloodstream infection in critically ill patients.
OBJECTIVE
The differential time to positivity (DTTP), defined as the difference in time necessary for the blood cultures taken by a peripheral puncture and through the catheter to become positive has been suggested to be useful in differentiating between catheter-related bloodstream infection (CR-BSI) and other sources of bacteremia. A DTTP of >120 mins was found predominantly in CR-BSI. The objective of our study was to investigate whether DTTP is useful for the diagnosis of CR-BSI in a medical-surgical intensive care unit.


METHODS
Prospective clinical study.


METHODS
A 60-bed medical-surgical intensive care unit of a university hospital.


METHODS
One hundred consecutive adult patients from whom catheter(s) were to be removed for suspected CR-BSI were studied.


METHODS
A blood culture (using aerobic and anaerobic culture bottles) was first taken from a new puncture site. Next, a blood culture was taken through every intravascular catheter in place.


RESULTS
DTTP was calculated using the automated BacT/Alert blood culture system. Three patients had CR-BSI and nine patients had noncatheter-related bacteremia. Five patients had catheter-related sepsis without proven bacteremia. There was no significant difference in median DTTP between patients with CR-BSI and noncatheter-related bacteremia (2.1 hrs and 3.3 hrs, respectively; p =.6). Moreover, catheter-related sepsis in patients without bacteremia could not be detected using DTTP.


CONCLUSIONS
DTTP seems not to be useful for the diagnosis of CR-BSI in a medical-surgical intensive care unit.
Rijnders
B J
BJ
Department of Internal Medicine, University Hospital Leuven, Leuven, Belgium.
Verwaest
C
C
Peetermans
W E
WE
Wilmer
A
A
Vandecasteele
S
S
Van Eldere
J
J
Van Wijngaerden
E
E
D000328:Adult; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D016470:Bacteremia / Q000175:diagnosis* / Q000209:etiology; D001800:Blood Specimen Collection / Q000379:methods*; D002405:Catheterization, Central Venous / Q000009:adverse effects*; D002406:Catheterization, Peripheral / Q000009:adverse effects*; D018929:Cell Culture Techniques / Q000379:methods*; D003937:Diagnosis, Differential; D006801:Humans; D007362:Intensive Care Units; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D013997:Time Factors
D000900:Anti-Bacterial Agents