From those who brought you “getting to zero”

Here’s a comment that has received an unusually robust response on the Emerging Infections Network:

My hospital system plans to do blood cultures on all patients who are admitted with a central line in place (decision not yet final, but momentum is great). Such cultures would prevent mis-labeling of community-acquired infections as hospital-acquired, if infection actually happened to be present on admission and was not clinically suspected. This would allow upgrade of DRGs, to increase reimbursement, and would prevent a CLABSI from being labeled wrongly as hospital acquired. Our state has mandatory reporting and comparison of CLABSI for all hospitals and there is great pressure to reduce rates. I have great reservations about this practice, having seen this done before when blood contaminants stalled the entire purpose of the admission, adding to antibiotic use and length of stay. Does anyone else have opinions or experience with this practice?

So just to be clear: as a result of pressure to get their publicly reported rates of CLABSI to zero (and to maximize reimbursement), this hospital plans to obtain admission blood cultures on every patient with a central venous catheter. Not only will these non-indicated cultures drive up healthcare costs, they will result in untold days of unnecessary antibiotic use (for the blood culture contaminants that will greatly outnumber true pathogens), increase pressure for antimicrobial resistance, prolong hospital stays, and could result in potentially lethal adverse effects (drug reactions, C. difficile, etc.).

Happy Monday!

Sterile gloves for drawing blood cultures?

Photo: RightHealth.com

A new study in the Annals of Internal Medicine evaluated whether blood culture contamination could be reduced if the phlebotomist wore sterile gloves. The study was performed in a 1600-bed Korean teaching hospital where all blood cultures are drawn by interns. The design was a cluster randomized crossover trial. Over 10,500 blood cultures were evaluated, and a contaminant was defined when only 1 of 2 of more blood culture sets were positive for skin flora (which in this study included enterococci).

The authors found a reduction in contaminated cultures from 1.1% to 0.6% (OR 0.57, p 0.009) with sterile gloves.

It's worth pointing out that cultures drawn through lines were excluded, as were cultures obtained in the Emergency Department (an area of high contamination rates in some hospitals), pediatrics wards and surgical wards. In addition, povidone-iodine was used as the skin disinfectant.

When I was a resident, all blood cultures were drawn by housestaff and I proudly recall that I never had a contaminated blood culture (and I did wear sterile gloves). But we had a vested interest in avoiding contaminants, as it would mean drawing more cultures and potentially extending the patient's hospital stay, all of which meant more work for us.

A really easy way to reduce blood culture contamination

A new paper in the Journal of Clinical Microbiology caught my eye. By making a minor modification in blood culture collection technique, the study's authors demonstrated a reduction in blood culture contamination by 50% (2.8% vs. 1.4%, p=0.005). Using a butterfly needle and a vacutainer system, an extra tube was used to collect the first mL of blood. This tube was discarded, then the blood was obtained for the culture. The authors hypothesized that skin fragments contaminated with bacteria from the venipuncture can lead to contamination of the blood culture. By discarding the initial 1 mL containing the skin fragments, a significant reduction in blood culture contamination was noted.

Phlebotomists, and why we like them, part 2

Mike’s post points to the cost savings that may be achieved through reduced blood culture contamination rates, a strong argument for phlebotomy teams.   The article Mike cited focused on emergency departments, but phlebotomists offer even more benefits in the hospital, including improved bloodstream infection surveillance.  Since coagulase-negative staphylococci (CoNS) are both the most common cause of central line associated bloodstream infection (CLABSI) and the most common blood culture contaminant, high contamination rates lead to a lot of misclassification.   

The problem of contaminants being classified as CLABSIs has been reduced by the change in NHSN surveillance definition, which now requires 2 or more cultures positive for common skin contaminants (like CoNS) to define a CLABSI.  The most likely form of misclassification now is probably failure to identify true CLABSIs due to skin contaminants—either because 1 positive out of 2 cultures still has a predictive value of 20% for CLABSI, or because only one culture was obtained (often through a central line).  Incorrect blood culture practices like this are much more likely when trained phlebotomists are unavailable, leaving blood cultures to be obtained by busy nurses, residents or medical students.

So let’s hope that tighter hospital budgets don’t result in short-sighted decisions to cut back on phlebotomy services—the costs of increased blood culture contamination rates and substandard blood culture collection practices are likely to far outweigh any savings……

Spend a little, save a lot?

Many hospitals, including mine, have struggled with high rates of contaminated blood cultures. After several years and a ton of work, we have been able to reduce our contamination rate by over half. Contamination rates in the Emergency Department (ED) are especially important since EDs draw a significant proportion of the blood cultures in the hospital. My hospital does not have a phlebotomy team and I have often wondered how much improvement we could gain with one.

An interesting study from Parkland Hospital has been published in the April edition of the Journal of Clinical Microbiology which shows that blood cultures drawn by phlebotomists in the ED were significantly less likely to be contaminated than those drawn by non-phlebotomists (roughly 3% vs. 6-7%). The authors then compared median hospital charges between the patients with contaminated blood cultures and those with negative blood cultures and ascribed the $8,720 difference in charges to the contaminated blood culture. This methodology has a great deal of potential for bias since the patients with contaminated cultures were not matched in any way to those with negative blood cultures. The authors contend that avoiding just 5 contaminated cultures would pay for one full time phlebotomist. While I do worry about this conclusion, even if the authors erred by a factor of 10 in their estimates of attributable charges, reducing the rate of contaminated blood cultures from 6% to 3% in an ED that draws 13,800 cultures per year (as does Parkland), would still pay for 9 phlebotomists at $40,000 annually for each. The findings were strong enough for Parkland to hire round-the-clock phlebotomists in their ED, and because of this paper I hope to convince my hospital to do the same.