Lung Ultrasound in Emergency and Critically Ill Patients: Number of Supervised Exams to Reach Basic Competence.

BACKGROUND: Lung ultrasound is increasingly used in critically ill patients as an alternative to bedside chest radiography, but the best training method remains uncertain. This study describes a training curriculum allowing trainees to acquire basic competence. METHODS: This multicenter, prospective, and educational study was conducted in 10 Intensive Care Units in Brazil, China, France and Uruguay. One hundred residents, respiratory therapists, and critical care physicians without expertise in transthoracic ultrasound (trainees) were trained by 18 experts. The main study objective was to determine the number of supervised exams required to get the basic competence, defined as the trainees' ability to adequately classify lung regions with normal aeration, interstitial-alveolar syndrome, and lung consolidation. An initial 2-h video lecture provided the rationale for image formation and described the ultrasound patterns commonly observed in critically ill and emergency patients. Each trainee performed 25 bedside ultrasound examinations supervised by an expert. The progression in competence was assessed every five supervised examinations. In a new patient, 12 pulmonary regions were independently classified by the trainee and the expert. RESULTS: Progression in competence was derived from the analysis of 7,330 lung regions in 2,562 critically ill and emergency patients. After 25 supervised examinations, 80% of lung regions were adequately classified by trainees. The ultrasound examination mean duration was 8 to 10 min in experts and decreased from 19 to 12 min in trainees (after 5 vs. 25 supervised examinations). The median training duration was 52 (42, 82) days. CONCLUSIONS: A training curriculum including 25 transthoracic ultrasound examinations supervised by an expert provides the basic skills for diagnosing normal lung aeration, interstitial-alveolar syndrome, and consolidation in emergency and critically ill patients.

Construction of a Hr mutant knockout mouse model and phenotypic analysis / 中国比较医学杂志

Objective To establish a Hr mutant knockout mouse model to study the function of Hr gene.Methods Transcription activator-like effector nucleases ( TALENs) technique was used to disrupt the mouse Hr locus,creating heritable mutations that eliminate Hr function to explore the effects of Hr on hair development and provide a good model to study the function of Hr gene.The phenotype of Hr -/- mice was observed after birth and skin histology of the transgenic mice was studied by light microscopy.Results It was shown that a F0 mouse with the 2 -bp deletion in Hr gene ranging from 86 to 87 base pairs was obtained.The male mice with clear deletion of the Hr fragment and with obvious frame shifting were mated with wild-type female mice, and F1 mice were achieved.The heterozygous males mated with females to generate the F2 homozygous mice.The first hair coat of Hr-/- mice developed normally.Beginning from 14 days after birth, however, there was a rapid hair loss.The mices were completely hairless except for a few vibrissae at 30 days. Histologically, two characteristic structures appeared, the utriculus and dermal cyst.Conclusions The results suggest that Hr -/- mice are successfully created using TALENs, and Hr is important for regulating hair development, which could explain at least in part the hair loss and be applied to study the mechanism of hair growth and development disorder.