The Barriers and Facilitators to Transfer of Ultrasound-Guided Central Venous Line Skills From Simulation to Practice: Exploring Perceptions of Learners and Supervisors

Phenomenon: Ultrasound-guided central venous line insertion is currently the standard of care. Randomized controlled trials and systematic reviews show that simulation is superior to apprenticeship training. The purpose of this study is to explore, from the perspectives of participants in a simulation-training program, the factors that help or hinder the transfer of skills from simulation to practice. Approach: Purposeful sampling was used to select and study the experience and perspective of novice fellows after they had completed simulation training and then performed ultrasound-guided central venous line in practice. Seven novice pediatric intensive care unit fellows and six supervising faculty in a university-affiliated academic center in a large urban city were recruited between September 2012 and January 2013. We conducted a qualitative study using semistructured interviews as our data source, employing a constructivist, grounded theory methodology. Findings: Both curricular and real-life factors influence the transfer of skills from simulation to practice and the overall performance of trainees. Clear instructions, the opportunity to practice to mastery, one-on-one observation with feedback, supervision, and further real-life experiences were perceived as factors that facilitated the transfer of skills. Concern for patient welfare, live trouble shooting, complexity of the intensive care unit environment, and the procedure itself were perceived as real-life factors that hindered the transfer of skills. Insights: As more studies confirm the superiority of simulation training versus apprenticeship training for initial student learning, the faculty should gain insight into factors that facilitate and hinder the transfer of skills from simulation to bedside settings and impact learners' performances. As simulation further augments clinical learning, efforts should be made to modify the curricular and bedside factors that facilitate transfer of skills from simulation to practice settings.     

Retinal anatomy and visual performance in a diurnal cone-rich laboratory rodent, the Nile grass rat (Arvicanthis niloticus)

Unlike laboratory rats and mice, muridae of the Arvicanthis family (A. ansorgei and A. niloticus) are adapted to functioning best in daylight. To date, they have been used as experimental models mainly in studies of circadian rhythms. However, recent work aimed at optimizing photoreceptor-directed gene delivery vectors (Khani et al. [2007] Invest Ophthalmol Vis Sci 48:3954-3961) suggests their potential usefulness for studying retinal pathologies and therapies. In the present study we analyzed the retinal anatomy and visual performance of the Nile grass rat (A. niloticus) using immunohistofluorescence and the optokinetic response (OKR). We found that approximately 35-40% of photoreceptors are cones; that many neural features of the inner retina are similar to those in other diurnal mammals; and that spatial acuity, measured by the OKR, is more than two times that of the usual laboratory rodents. These observations are consistent with the known diurnal habits of this animal, and further support its pertinence as a complementary model for studies of structure, function, and pathology in cone-rich mammalian retinae.     

The electroretinogram (ERG) of a diurnal cone-rich laboratory rodent, the Nile grass rat (Arvicanthis niloticus)

The most widespread models to study blindness, rats and mice, have retinas containing less than 3% cones. The diurnal rodent Arvicanthis niloticus retina has around 35% cones. Using ERG recordings, we studied retina function in this species. Several features differed from that reported in rats and mice: (a) fivefold larger photopic a-wave amplitudes; (b) photopic hill effect in Nile grass rats only; and (c) flicker amplitude plateau between 5 to 35 Hz with fusion beyond 60 Hz in Nile grass rats only. We conclude that A. niloticus might complement rats and mice for studying retinal function and pathologies involving cones.     

Effects of deficiency of the G protein Gsα on energy and glucose homeostasis

G_sα is a ubiquitously expressed G protein α-subunit that couples receptors to the generation of intracellular cyclic AMP. The G_sα gene GNAS is a complex gene that undergoes genomic imprinting, an epigenetic phenomenon that leads to differential expression from the two parental alleles. G_sα is imprinted in a tissue-specific manner, being expressed primarily from the maternal allele in a small number of tissues. Albright hereditary osteodystrophy is a monogenic obesity disorder caused by heterozygous G_sα mutations but only when the mutations are maternally inherited. Studies in mice indicate a similar parent-of-origin effect on energy and glucose metabolism, with maternal but not paternal mutations leading to obesity, reduced sympathetic nerve activity and energy expenditure, glucose intolerance and insulin resistance, with no primary effect on food intake. These effects result from G_sα imprinting leading to severe G_sα deficiency in one or more regions of the central nervous system, and are associated with a specific defect in melanocortins to stimulate sympathetic nerve activity and energy expenditure.