Toward an Objective Diagnostic Test for Bacterial Cellulitis.

BACKGROUND: Prior studies repeatedly showed that cultures of skin lesions diagnosed as "cellulitis" are usually negative. However, lack of a gold standard for diagnosis (against which culture might be judged) and failure to assess the human immune response are important limitations of prior work. In this pilot study, we aimed to develop a criterion standard for research on bacterial cellulitis, to evaluate the sensitivity of procalcitonin for bacterial cellulitis, and to use gene expression analysis to find other candidate diagnostic markers. METHODS: We classified lesions via biopsies, 16s rRNA gene detection, culture, and histopathology. We quantified procalcitonin expression in blood. We also used Nanostring technology to quantify transcription of immunomodulators that may distinguish cases from inflamed controls. RESULTS: Of 28 participants, 15 had a clinical diagnosis of cellulitis, six had a diagnosis of non-infectious dermatitis, and seven were normal volunteers. Of the "cellulitis" patients, three (20%) had pathogens isolated, and were designated confirmed cases. Procalcitonin was undetectable in all three. HLA-DQA1 was expressed 34-fold more in confirmed cases vs. controls (fold change of geometric mean). Heat maps depicting multiplex gene expression analysis revealed a distinct profile of gene expression in confirmed cases relative to comparators. CONCLUSIONS: Most "cellulitis" patients had microbiologically-negative biopsies. Procalcitonin was undetectable, and HLA-DQA1 elevated, in confirmed bacterial cases. Multivariable transcriptomic profiling results supported our algorithm's ability to identify patients with true bacterial cellulitis. A larger sample may allow discovery of an immunological signature capable of distinguishing bacterial cellulitis from its mimics in clinical practice.

Techniques and Trends, Success Rates, and Adverse Events in Emergency Department Pediatric Intubations: A Report From the National Emergency Airway Registry.

STUDY OBJECTIVE: We describe emergency department (ED) intubation practices for children younger than 16 years through multicenter prospective surveillance. METHODS: Academic and community EDs in the United States, Canada, and Australia recorded data electronically, from 2002 to 2012, with verified greater than or equal to 90% reporting. RESULTS: Ten of 18 participating centers provided qualifying data, reporting 1,053 encounters. Emergency physicians initiated 85% of intubations. Trainees initiated 83% (95% confidence interval [CI] 81% to 85%). Premedication became uncommon, reaching less than 30% by the last year. Etomidate was used in 78% of rapid sequence intubations. Rocuronium use increased during the period of study, whereas succinylcholine use declined. Video laryngoscopy increased, whereas direct laryngoscopy declined. The first attempt was successful in 83% of patients (95% CI 81% to 85%) overall. The risk of first-attempt failure was highest for infants (relative risk versus all others 2.3; 95% CI 1.8 to 3.0). Odds of first-attempt success for girls relative to boys were 0.57. The odds were 3.4 times greater for rapid sequence intubation than sedation without paralysis. The ultimate success rate was 99.5%. CONCLUSION: Because we sampled only 10 centers and most of the intubations were by trainees, our results may not be generalizable to the typical ED setting. We found that premedication is now uncommon, etomidate is the predominant induction agent, and rocuronium and video laryngoscopy are used increasingly. First-attempt failure is most common in infants.