Bottom line: In septic shock treated with hydrocortisone, the optimal blood-glucose level and insulin strategy are unknown.
Citation: Annane D, Cariou A, Maxime V, et al. Corticosteroid treatment and intensive insulin therapy for septic shock in adults: a randomized controlled trial. JAMA. 2010;303(4):341-348.
Mupirocin-Chlorhexidine Decolonization of Nasal S. Aureus Carriers Reduces Surgical-Site Infections
Clinical question: Can rapid screening and decolonization of nasal carriers of Staphylococcus aureus on admission reduce surgical-site S. aureus infections?
Background: More than 80% of healthcare-associated (HCA) S. aureus infections are endogenous in origin. High-level nasal carriers have a three- to sixfold increased risk of infection with this organism compared with noncarriers and low-level carriers. Decolonization of nasal and extranasal S. aureus on admission might reduce this risk of infection.
Study design: Randomized, double-blinded, placebo-controlled, multicenter trial.
Setting: Three university hospitals and two general hospitals in the Netherlands.
Synopsis: In this study, 918 mostly surgical patients with nasal S. aureus identified preoperatively by PCR tests were randomized to decolonization versus placebo. The five-day decolonization protocol involved mupirocin nasal ointment and chlorhexidine soap baths. Decolonization reduced length of stay by nearly two days. Through six weeks postdischarge, the cumulative incidence of S. aureus infection was 3.4% after decolonization versus 7.7% with placebo (RR 0.42; 95% CI, 0.23-0.75). Among the sites of infection, deep surgical sites had the greatest risk reduction (RR 0.21; 95% CI, 0.07-0.62).
The results of this study are encouraging, but a few limitations should be noted. The decolonization protocol lasted five days, which might make implementation less practical. Also, the relative contributions of mupirocin and chlorhexidine are unclear.
S. aureus is important, but it represents a minority of surgical-site infections; the effect of the protocol on other organisms is unknown. Lastly, MRSA is not prevalent in the Netherlands and no carriers were identified in the study. Although the protocol was designed to eradicate MRSA, such carriers might have different carriage patterns requiring throat swabs in addition to nasal swabs.
Bottom line: Preoperative detection of S. aureus nasal carriage and nasal and extranasal decolonization significantly reduced endogenous S. aureus infection and length of stay. Decolonization might be most beneficial for carriers at increased risk of deep infection, such as those undergoing cardiac surgery.
Citation: Bode LG, Kluytmans JA, Wertheim HF, et al. Preventing surgical-site infections in nasal carriers of Staphylococcus aureus. N Engl J Med. 2010;362(1):9-17.
ABCD2 Is a Poor Predictor of Early Ischemic Stroke after Transient Ischemic Attack
Clinical question: How well does the ABCD2 score predict stroke risk within seven days of transient ischemic attack (TIA)?
Background: After TIA diagnosis, the seven-day risk of ischemic stroke is approximately 5%. Identifying these high-risk patients might facilitate ED decision-making. The ABCD2 score, a prediction tool for stroke after TIA, might be useful but has not been prospectively validated in a large, broad-patient population.
Study design: Prospective validation study, convenience sample.
Setting: Sixteen hospitals in North Carolina.
Synopsis: The ABCD2 score (range 0-7 points) predicts stroke risk after TIA. The investigators evaluated the accuracy of ABCD2 in predicting seven-day ischemic stroke risk in a convenience sample of 1,667 TIA patients. Strokes were categorized as disabling or nondisabling.
Overall, the score was poorly predictive of all ischemic stroke (c stat 0.59) and moderately predictive of the subset of disabling ischemic stroke (c stat 0.71). The ABCD2 had the most discriminatory power when used to identify patients at low risk of disabling stroke (0-3 points); for these patients, the negative likelihood ratio (LR) was 0.16 (0.04-0.64).
The study is the largest published external-validation study of the ABCD2 score, but it had significant limitations that should be considered. There was potential sampling bias because of nonconsecutive sampling, and unaccounted patients with TIA were discharged from the ED. Furthermore, ABCD2 scores were incalculable for 35% of patients, although the authors report that imputed data did not change the findings significantly.