Objectives: Prediction of difficult laryngoscopy in emergency care settings is challenging. The preintubation clinical screening tests may not be applied in a large number of emergency intubations due to the patient's clinical condition. The objectives of this study were 1) to determine the utility of sonographic measurements of thickness of the tongue, anterior neck soft tissue at the level of the hyoid bone, and thyrohyoid membrane in distinguishing difficult and easy laryngoscopies and 2) to examine the association between sonographic measurements (thickness of tongue and anterior neck soft tissue) and difficult airway clinical screening tests (modified Mallampati score, thyromental distance, and interincisor gap).Methods: This was a prospective observational study at an academic medical center. Adult patients undergoing endotracheal intubation for an elective surgical procedure were included. The investigators involved in data collection were blinded to each other's assessments. Demographic variables were collected preoperatively. The clinical screening tests to predict a difficult airway were performed. The ultrasound (US) measurements of tongue and anterior neck soft tissue were obtained. The laryngoscopic view was graded using Cormack and Lehane classification by anesthesia providers on the day of surgery. To allow for comparisons between difficult airway and easy airway groups, a two-sided Student's t-test and Fisher's exact test were employed as appropriate. Spearman's rank correlation coefficients were used to examine the association between screening tests and sonographic measurements. Results:The mean (±standard deviation [SD]) age of 51 eligible patients (32 female, 19 male) was 53.1 (±13.2) years. Six of the 51 patients (12%, 95% confidence interval [CI] = 3% to 20%) were classified as having difficult laryngoscopy by anesthesia providers. The distribution of laryngoscopy grades for all subjects was 63, 25, 4, and 8% for grades 1, 2, 3, and 4, respectively. In this study, 83% of subjects with difficult airways were males. No other significant differences were noted in the demographic variables and difficult airway clinical screening tests between the two groups. The sonographic measurements of anterior neck soft tissue were greater in the difficult laryngoscopy group compared to the easy laryngoscopy group at the level of the hyoid bone (1.69, 95% CI = 1.19 to 2.19 vs. 1.37, 95% CI = 1.27 to 1.46) and thyrohyoid membrane (3.47, 95% CI = 2.88 to 4.07 vs. 2.37, 95% CI = 2.29 to 2.44). No significant correlation was found between sonographic measurements and clinical screening tests.Conclusions: This pilot study demonstrated that sonographic measurements of anterior neck soft tissue thickness at the level of hyoid bone and thyrohyoid membrane can be used to distinguish difficult and easy laryngoscopies. Clinical screening tests did not correlate with US measurements, and US was able to detect difficult laryngoscopy, indicating the limitations of the conventional screening tests for predicting ...

Demand for bedside ultrasound in medicine has created a need for earlier exposure to ultrasound education during the clinical years of undergraduate medical education. Although bedside ultrasound is often used for invasive medical procedures, there is no standardized educational model for procedural skills that can provide the learner a real-life simulated experience. The objective of our study was to describe a unique fresh cadaver preparation model, and to determine the impact of a procedure-focused ultrasound training session. This study was a cross-sectional study at an urban academic medical center. A sixteen-item questionnaire was administered at the beginning and end of the session. Fifty-five third year medical students participated in this 1-day event during their surgical clerkship. Students were trained to perform the following ultrasound-guided procedures: internal jugular vein cannulation, femoral vein cannulation femoral artery cannulation and pericardiocentesis. Preparation of the fresh cadaver is easily replicated and requires minor manipulation of cadaver vessels and pericardial space. Fifty-five medical students in their third year participated in this study. All of the medical students agreed that US could help increase their confidence in performing procedures in the future. Eighty percent (95 % CI 70-91 %) of students felt that there was a benefit of learning ultrasound-based anatomy in addition to traditional methods. Student confidence was self-rated on a five-point Likert scale. Student confidence increased with statistical significance in all of the skills taught. The most dramatic increase was noted in central venous line placement, which improved from 1.95 (SD = 0.11) to 4.2 (SD = 0.09) (p < 0.001). The use of fresh cadavers for procedure-focused US education is a realistic method that improves the confidence of third year medical students in performing complex but critical procedures.

After a focused simulation training session, ED nurses had a high level of comfort using ultrasound for vascular access. Despite having a moderate degree of confidence, ED nurses were accurate in identifying vascular anatomy and performing ultrasound-guided vascular access.

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