Blood cultures

[zacarias, ASN, RN]

Hey all,

I'm a new nurse working on a gen medicine unit in a huge teaching hospital in the Pacific Northwest. Anyway, I have a question regarding obtaining blood cultures.

I had a patient the other day who is ESLD and being worked up for liver transplant. He was having decreased LOC all of the sudden and so they thought maybe either anemia, worsening of encephalopathy, or infection, so the doc did a diagnostic paracentesis and cultured it. I drew blood cultures and then someone else drew blood cultures later in the day.

My question is that what can I do to almost eliminate the risk of contamination? I fear I'm contaminating the blood cultures I get. The paracentesis culture came back with Staph aureus coagulase-neg (often what's seen in contamination) and my blood cultures came back the same. I mean on one hand I think I may have contaminated them but then it seems unlikely that the doctor also would have contaminated the paracentesis samples too! Then I gave him a dose of some cephalosporin after which the other two cultures were drawn. They still don't show any growth but I wonder if the lab new he had gotten that one dose of abx. Anyway, maybe I'm worrying way too much about this, but I want to make sure I'm doing my best regarding such a sensitive test like blood cultures.

Any suggestions?

[TonyafutureRN]

I used to be a phlebotomist for a hospital lab and our procedure for drawing blood cultures included: not opening the top of the bottles until ready to use, cleansing the venipuncture site twice, first with alcohol then with betadine, going from the inside (where you're going to put the needle) in a circular motion to push the germs out and away from the site, and not touching the site again after cleaning it. Then we would put them in a bag and deliver to the lab right away. I'm not sure if this is what you were looking for, but it's all I know. Hope this helps. Tonya

[jnette, ASN, EMT-I]

I also always wipe the stopper underneath the metal cap with betadine as well... then be sure not to touch the rubber stopper after that. :)

[Emperess]

I've always wiped the stopper underneath the bottle cap with alcohol. I thought I learned not to use betadine because it reacts with the rubber or something? Anyone?

[nialloh, RN]

Originally posted by Emperess

I've always wiped the stopper underneath the bottle cap with alcohol. I thought I learned not to use betadine because it reacts with the rubber or something? Anyone?

We always use betadine.

[TonyafutureRN]

I too was told not to wipe it with betadine, but my supervisor gave a different reason. She said when the blood went through the stopper into the tube, going through the betadine could kill some of the bacteria from the blood that the bc's were testing for. I don't know if it would actually be enough to do that, but that's what we were told, only to wipe them with alcohol. Tonya

[jnette, ASN, EMT-I]

hmmmm... interesting. And even on the culture package insert it says to wipe stoppers with betadine.

[Rapheal]

Also remember to change needles before putting the blood in the culture bottles.

PS. What was his ammonia level?

[purplemania, BSN, RN]

Are you testing two separate sites at the same time? Also, the betadine cleansing needs to be done for about 2 minutes---seems like an eternity but may help your patient in the long run.

[Gldngrl]

Our hospital changed its policy about a year ago to using chlorhexidine for blood culture prep instead of betadine. Preliminary research supported lower contamination rates. We use chlorhexidine for all of our wound care and prep for line placements because our pts are immunocompromised and the product continues to inhibit bacterial growth for hours, I believe.

MMB