Q: Drawing blood cultures from 'just inserted' central venous catheter (CVC)? (select one)
A) decreases the likelihood of false-positive blood culture
B) increases the likelihood of false-positive blood culture
Unfortunately, the 'bad' practice of drawing blood cultures from the just inserted CVC is on the rise under the perception that the site is clean and will not affect the result of blood culture. On the contrary, it falsely increases the chances of positive blood culture. If it's not possible to obtain both cultures 'peripherally', an attempt should be made at least to get one culture peripherally - and labeled properly before sending to the laboratory.
Boyce JM, Nadeau J, Dumigan D, et al. Obtaining blood cultures by venipuncture versus from central lines: impact on blood culture contamination rates and potential effect on central line-associated bloodstream infection reporting. Infect Control Hosp Epidemiol 2013; 34:1042.