Hand hygiene in the emergency department

ICHE has an interesting paper up on hand hygiene (HH) in the Brigham and Women’s emergency department. As part of a QI program, the ED deployed 5 trained observers and an infection preventionist to performing HH audits for 16 months. Impressively, they covered all days of the week, and all shifts (much of our data on HH comes from weekday first-shift observations, which may differ from what one might find on weekends or at night). The overall adherence was good, at ~90% (the observers were known to the ED personnel, but this is still an excellent rate of HH). The most notable findings included (a) physicians had slightly higher adherence than nurses, which runs counter to the conventional wisdom, (b) transport personnel had the lowest adherence (<70%), and (c) hallway location (which by definition translates to an overcrowded ED) was associated with lower adherence (82%, compared with 91% in a private room).

Because I’m always on the lookout for more reasons to despise contact precautions, I immediately seized on this last finding. As Mike and his colleagues pointed out in a study published in March of this year, difficulty in finding beds for patients requiring contact precautions is one factor that exacerbates ED overcrowding. At Mike’s hospital, patients who required contact precautions waited in the ED for an hour longer than those who did not. Active detection and isolation programs make this problem even worse, as pointed out in this Irish study—patients colonized or infected with MRSA waited 2.5 hours longer in the ED than did those who were not identified as being at high-risk for MRSA.

In other words, not only does ED overcrowding lead to poorer HH and increased risk of pathogen transmission, but the patient population in many EDs may be “enriched” with MDRO carriers (who stay in EDs longer while awaiting a bed)!

Multiplex PCR and diagnosis of sepsis

Just came across a really nice paper in the Journal of Clinical Microbiology by Ephraim Tsalik, Chris Woods and others at Duke and the Durham VA. They tested whether multiplex real-time PCR can be a useful addition to blood culture in patients presenting with suspected sepsis to the ED of their two hospitals. Over an almost 6-year period they enrolled 306 patients with suspected sepsis (43 were eventually excluded for non-infectious etiology). Patients had blood samples taken within ~2-3 hours and a questionnaire administered to determine recent exposures and symptoms. Most of the confirmed etiologies were S. aureus (34%) and E. coli (23%).

Results showed that blood culture had a sensitivity of 25% vs. 20% for PCR, a similar negative predictive value (18% vs. 17%), and an area under the curve of 0.63 vs 0.60. Using blood culture as the gold standard, PCR had a sensitivity of 61%. Both PCR and culture detected organisms in 40 patients (38 were the same organism). As far as individual methods, there were 24 organisms only detected by PCR (largely E. coli and Klebsiella) and 52 only detected by blood culture (E. coli, S. pneumo, S. aureus and a large number of CoNS considered contaminants). Six species detected by culture were not in the PCR menu (e.g Listeria, Salmonella).

I think these results speak for themselves. Neither method is perfectly sensitive at this point suggesting that both methods should be used if possible to improve diagnosis. PCR can be quicker and detect additional organisms, but still missed a significant number. Interestingly, blood culture was more sensitive in detecting organisms from patients who had previously received antibiotics (P = 0.06). This is counter to what I would've suspected.

What I really liked about this paper is that it was completed in a way that was clinically useful since they enrolled patients as they presented to the ED and asked the question in the way a clinician would. This was not some convenient sample study which we so frequently see in diagnostic test comparisons. I also liked how they presented the information, giving the sensitivity/specificity, predictive values and AUC. It will be interesting to see if future studies can document a clinical benefit in terms of reduced mortality and length of stay when PCR is added to our diagnostic battery. Finally, I was impressed that this study was completed at all. Enrolling so many septic patients with questionnaires over such a long period of time is no small feat. The authors should be congratulated.