In a suspected central line-associated bloodstream infection (CLABSI), which action is part of the workup?

• A. Draw blood from a peripheral site before starting IV antibiotics
• B. Draw blood from the CVC after starting IV antibiotics
• C. Draw blood from the CVC and a peripheral site before starting IV antibiotics
• D. Obtain cultures only if symptoms persist

Answer: (C)

Evaluating a suspected CLABSI hinges on obtaining paired blood cultures from both the central line and a peripheral vein before starting antimicrobial therapy whenever feasible. This approach lets you determine if the catheter is the infection source by comparing time to positivity; if the catheter-derived culture becomes positive earlier than the peripheral one, it supports catheter-related bacteremia. Drawing from both sites before antibiotics minimizes the risk that antimicrobial therapy will suppress bacterial growth and lead to a false-negative result. Relying on a single site or delaying cultures until after antibiotics makes interpretation less reliable, and cultures aren’t only taken if symptoms persist. So, obtaining cultures from both the CVC and a peripheral site before starting IV antibiotics is the correct step.