Intravascular catheter tips

Intravascular catheters may include central, CVP, Hickman, Broviac, peripheral, arterial, umbilical, hyperalimentation, hemodialysis, port-a-cath and Swan-Ganz catheters.

Setup

Direct examination

Not indicated

Culture

If more than 5 cm is submitted cut the distal 5 cm using sterile scissors. Roll the segment back and forth 4 times across the surface of the BA using sterile forceps.

Media Incubation
Blood Agar (BA) CO2, 35°C x 72 hours

Interpretation Examine the BA plate after 24 and 48 hours incubation.

Any growth of S. aureus, beta-haemolytic streptococci, Streptococcus anginosus group, Pseudomonas spp., Gram negative bacilli and yeasts are significant. Quantitate and identify.

Other organisms should be quantitated and identified only if >15 colonies of that organism are present and there are <3 different bacterial types. Otherwise (3 or more types), simply list the morphotypes with quantitation.

Reporting

Negative Report

“No growth”

For non-significant organisms:

Report as “<15 colonies of (list morphotypes of non-significant organisms)”.
No susceptibility testing required.

Report as “>15 colonies of (list morphotypes of mixed non-significant organisms)”.
No susceptibility testing required.

Positive Report

For significant organisms:

Report as “<15 colonies of (organism name)” or “>15 colonies of (organism name)”.
Report with appropriate susceptibilities.

References H.D. Isenberg. 2004. Specimen Collection, Transport and Acceptability p. 2.1.1 – 2.1.28. In Clinical Microbiology Procedures handbook, 2nd Edition, Vol 1 ASM Press, Washington, D.C
H.D. Isenberg, 2004. Wound Cultures – Wound and Soft Tissue Cultures, p. 3.13.1.1 – 3.13.1.16. In Clinical Microbiology Procedures Handbook, 2nd Edition, Vol 1 ASM Press, Washington, D.C.