Comparing the Utility of Landmark-Palpation Guided to Ultrasound-Guided Teaching Methodologies for Subclavian Central Venous Access Using a Formalin-Embalmed Cadaver Model.

Background: Low-risk and realistic simulation strategies are needed to train clinical learners to perform hands-on invasive procedures. This follow-up study compares the utility of landmark-guided palpation-based to ultrasound-guided teaching techniques for subclavian central venous access using formalin-embalmed cadavers. Methods: The subclavian veins of 3 cadavers were imaged with ultrasound to evaluate vein patency before palpation-based venous access was attempted. Twenty-three first-year medical students were trained to access the subclavian vein using palpation-based techniques. Training involved ten minutes of didactic orientation and ten minutes of hands-on practical instruction using cadavers. Participant confidence was measured using a 10-point Likert scale on pre- and post-training questionnaires. Objective skills testing for each participant included quantifying the number of skin punctures and recording the time elapsed from first skin puncture to fluid flashback into the syringe. Data was analyzed using a generalized linear model (GLM) approach. Results: Participant confidence significantly increased following training in both ultrasound and palpation training groups across all questionnaire items (P<0.001). The ultrasound group had fewer skin punctures (P<0.001) and fewer failures (1) than the palpation group (6). Participants in the ultrasound group were more confident than those in the palpation group in their ability to locate the vein and select the optimal site for needle access (P<0.05). Conclusion: Formalin-embalmed cadavers provide a safe, stress-free, and effective means by which to train students in subclavian vein access using both palpation and ultrasound-based techniques. Repeated practice accessing and aspirating fluid from a cadaveric subclavian vein significantly increases trainee confidence, an essential factor in physician performance that may lead to fewer complications. Introducing this type of low-risk and hands-on practice may be beneficial for trainees before they attempt subclavian vein access on live patients.

A Narrative Review of Common Uses of Ophthalmic Ultrasound in Emergency Medicine.

BACKGROUND: The timely evaluation of ocular conditions in the emergency department (ED) can be difficult due to a general lack of specialized equipment, trained personnel, and the time-sensitive nature of emergent ocular conditions. Recently, the use of ocular point-of-care ultrasound (POCUS) has been shown to be particularly useful in the ED. POCUS can be used to promptly diagnose various ocular pathologies, which include ocular trauma, vitreous hemorrhage, central retinal artery occlusion, and retinal detachment. OBJECTIVES: This narrative review seeks to inform the reader of current literature regarding the use of POCUS for the assessment of various ocular emergencies in the ED. The goal of this review is to provide the emergency physician with succinct and up-to-date information and instruction regarding the current uses of POCUS for patients presenting with particular ocular emergencies. Ocular pathologies that are common (ocular trauma) or for which ultrasound is particularly useful (such as retinal detachment) are discussed. Other ocular pathologies are also briefly discussed, such as central retinal artery occlusion, which is a promising new application for ultrasound evaluation. DISCUSSION: There have been many studies that provide evidence for the utility of POCUS in the evaluation of trauma and other ocular pathologies, including vitreous hemorrhage, retinal detachment, and central retinal artery occlusion. CONCLUSIONS: Ocular POCUS is a useful modality in the evaluation of acute ocular complaints in the ED. Emergency physicians should be aware of these findings and feel confident in the utility of ocular POCUS in the ED.

Using formalin embalmed cadavers to teach fracture identification with ultrasound.

BACKGROUND: Ultrasound is being utilized more frequently to diagnose fractures in bone and track fracture reduction quickly, and without radiation exposure in the ED. Realistic and practical methods of teaching sonographic fracture identification to medical trainees are needed. The objective of this study is to determine the feasibility of using formalin-embalmed human cadavers in teaching medical trainees to use ultrasound to identify synthetic fractures in tibia, radius, and metacarpal bones. METHODS: First-year medical students attended an orientation presentation and a 15-min scanning workshop, to evaluate fractures in cadaver bones with an instructor. Next participants independently scanned bones to determine if a fracture was present. Questionnaires were given that assessed participant self-confidence and ability to evaluate still ultrasound images for fracture and differentiate between tissue layers before, after, and 5 months following training. RESULTS: Participants were collectively able to scan and differentiate between fractured and unfractured bone in 75% of 186 total bone scanning attempts (tibia: 81% correct, metacarpal: 68% correct, radius: 76% correct). When evaluating still ultrasound images for fracture, participants' scores rose significantly following training from an average score of 77.4 to 91.1% (p = 0.001). Five months post-training, scores fell slightly, to an average of 89.8% (p = 0.325). CONCLUSIONS: Ultrasound images of formalin-embalmed cadaveric fractures are of sufficient quality to use in teaching fracture identification to medical trainees. With only 15 minutes of scanning experience, medical trainees can learn to independently scan and significantly increase their ability to identify fractures in still ultrasound images.