Ultrasound in Causes of Stridor in Children.

Airway ultrasound (US) is an easily available, portable, radiation-free imaging modality for quick, non-invasive, dynamic evaluation of the airway without sedation. This is useful in children with stridor, which is an emergency due to upper airway obstruction requiring immediate management. Several causes of stridor including laryngomalacia, laryngeal cyst, subglottic hemangioma, vocal cord palsy, and lymphatic malformations can be evaluated accurately. Thin musculature and unossified cartilages in children provide a good acoustic window. Thus, airway US is valuable, but underutilized for the evaluation of children with stridor. In this case-based review, we describe the technique, indications, anatomy, and pathologies on airway US.

Diagnostic Performance of Airway Ultrasound for the Assessment of Difficult Laryngoscopy: A Systematic Review and Meta-Analysis.

OBJECTIVE: This study aimed to review and appraise the evidence regarding airway ultrasound assessment in predicting difficult laryngoscopy in adult patients. DESIGN: A systematic review of the literature was conducted according to the Cochrane collaboration guidelines and the recommendations for the systematic review and meta-analysis of diagnostic studies. Observational studies that evaluated the diagnostic performance of airway ultrasound for the prediction of difficult laryngoscopy were included for consideration. SETTING: Literature searches were performed in 4 databases (PubMed [Medline], Embase, Clinical Trials, and Google Scholar) to identify all observational studies using any ultrasound technique to assess difficult laryngoscopy. The search terms included "sonography," "ultrasound," "airway," "difficult airway," "difficult laryngoscopy," "Cormack," "risk factors," "ultrasound at the point of care," "difficult ventilation," "difficult intubation" and others, combined with sensitive filters. The search was done for studies performed in the last 20 years in English or Spanish. PARTICIPANTS: Adult patients older than 18 years old under general anesthesia for an elective procedure. Evident anatomic airway abnormalities, obstetric populations, those using an alternative imaging method besides ultrasound, and animal studies were excluded. INTERVENTIONS: Preoperative bedside ultrasound measuring distances and ratios from the skin to different reference points, such as the ratio of the hyomental distance in a neutral position (HMDN) and hyomental distance in extension (HMDR), HMDN, and the skin-to-epiglottis distance (SED), the preepiglottic area, and tongue thickness, among others. MEASUREMENTS AND MAIN RESULTS: A total of 24 studies evaluated the prediction of a difficult laryngoscopy using airway ultrasound. The diagnostic performance and the number of ultrasound parameters reported in the studies were variable. Meta-analysis was performed for 3 measurements consistently included in most studies. The SED and the HMDR ratio presented a sensitivity of 75% and 61%, respectively, and a specificity of 86% and 88%, respectively. The ratio of the preepiglottic distance to the epiglottic distance at the midpoint of the vocal cords (pre-E/E-VC) presented the best performance for predicting a difficult laryngoscopy (sensitivity: 82%, specificity: 83%, diagnostic odds ratio: 22.2). CONCLUSION: With the currently available evidence, the 3 commonly used point-of-care ultrasound measures used to identify difficult laryngoscopy, (SED, HMDR, and pre-E/E-VC), showed better sensitivity and similar specificity to clinical measures. Future studies and more data may change the authors' confidence in these conclusions, given the wide variability of measurements noted in studies.

Point-of-Care Ultrasound (POCUS) for the Cardiothoracic Anesthesiologist.

Point-of-Care Ultrasound (POCUS) is a valuable bedside diagnostic tool for a variety of expeditious clinical assessments or as guidance for a multitude of acute care procedures. Varying aspects of nearly all organ systems can be evaluated using POCUS and, with the increasing availability of affordable ultrasound systems over the past decade, many now refer to POCUS as the 21st-century stethoscope. With the current available and growing evidence for the clinical value of POCUS, its utility across the perioperative arena adds enormous benefit to clinical decision-making. Cardiothoracic anesthesiologists routinely have used portable ultrasound systems for nearly as long as the technology has been available, making POCUS applications a natural extension of existing cardiothoracic anesthesia practice. This narrative review presents a broad discussion of the utility of POCUS for the cardiothoracic anesthesiologist in varying perioperative contexts, including the preoperative clinic, the operating room (OR), intensive care unit (ICU), and others. Furthermore, POCUS-related education, competence, and certification are addressed.

The diagnostic accuracy of point-of-care ultrasound parameters for airway assessment in patients undergoing intubation in emergency department-an observational study.

BACKGROUND: Endotracheal intubation is an essential resuscitative procedure in the emergency setting. Airway assessment parameters such as the Mallampati classification are difficult to perform in an emergency setting. As point-of-care ultrasound (POCUS) assessment of airway parameters does not require patients to perform any mandatory action, ultrasound may become the potential first-line noninvasive airway assessment tool in the emergency department (ED). The use of POCUS in the ED has not been sufficiently studied. Using POCUS in airway assessment for predicting difficult intubation may be the next step in successful airway management. METHODOLOGY: The study was an observational study conducted at the ED of the All India Institute of Medical Sciences (Rishikesh). The treating emergency physician recorded the patient history and systemic examination along with an indication for intubation. The POCUS assessment of airway parameters pre-epiglottis to epiglottic vocal cord ratio (Pre-E/E-VC), tongue thickness, hyomental distance, and distance from skin to the hyoid bone was performed by the study investigator. During laryngoscopy, Cormack-Lehane (CL) grading was assessed. The data was entered and analyzed. RESULTS: Seventy patients who required intubation in the ED were enrolled in the study. Among the study population, 48.6%, 28.6%, 14.3%, 1.4%, and 7.1% were classified with the following CL grading: 1, 2a, 2b, 3a, and 3b, respectively. At a cutoff of ≥ 1.86, Pre-E/E-VC predicts difficult laryngoscopy (AUC 0.835) with a sensitivity of 83% and a specificity of 94%. At a cutoff of ≥ 5.98 cm, tongue thickness predicts difficult laryngoscopy (AUC 0.78) with a sensitivity of 83% and a specificity of 88%. At a cutoff of hyomental distance ≤ 6 cm, it predicts difficult laryngoscopy with a sensitivity of 83% and a specificity of 88%. All parameters can act as a promising tool for predicting difficult laryngoscopy, with the single best parameter being Pre-E/E-VC. CONCLUSION: Assessment of the airway with POCUS may be helpful to the emergency physician when the clinical airway assessment parameters fail to predict difficult laryngoscopy as most patients requiring intubation are uncooperative. Assessment of the parameters in our study Pre-E/E-VC, tongue thickness, and hyomental distance can act as a promising tool for predicting difficult laryngoscopy in the emergency scenario.

Preoperative point-of-care neck ultrasound: beyond the airway.

PURPOSE: A preoperative point-of-care neck ultrasound, carried out during preoperative airway evaluation by extending the scans to the regions close to the larynx and trachea, can allow for the rapid identification of unknown pathologies or abnormalities in a cost-effective and non-invasive manner. This prospective, observational study examines a series of ultrasound findings in structures close to the airway, made through preoperative point-of-care neck ultrasound in a cohort of 230 patients. METHODS: We conducted a prospective observational study, enrolling 230 adult patients selected for elective abdominal surgery. The primary goal was to verify the predictive role of airway ultrasound in identifying difficult airways, while the secondary goal was to evaluate structures close to the airway such as jugular veins, carotid arteries, thyroid gland and soft tissues. RESULTS: Overall, preoperative point-of-care neck ultrasound proved to be an effective and reliable method of obtaining details about local or systemic pathologies, which could affect perioperative care. For example, the exam consistently revealed the presence of carotid plaques or venous congestion, which could be used to best determine the patient's cardiovascular risk or to instigate further investigations. It also allowed for more accurate central venous catheter placement planning and better airway management and it warned about possible thyroid or neoplastic pathologies that would have otherwise remained unknown. In some cases, information from preoperative point-of-care neck ultrasound has even led to modifications in perioperative therapy. CONCLUSION: Preoperative point-of-care neck ultrasound is fast, inexpensive, and non-invasive, and it can be easily performed by a properly trained professional during the preoperative airway ultrasound evaluation. It can be considered as a new preoperative assessment tool.

The role of upper airway ultrasonography in tracheal necrosis diagnosis: a case report.

BACKGROUND: Tracheal necrosis post endotracheal intubation is a rare life-threatening disease that can compromise airway patency. We demonstrated a novel usage of upper airway ultrasonography (USG) to diagnose tracheal necrosis. CASE PRESENTATION: A middle-aged smoking male presented with productive cough, noisy breathing and exertional dyspnea for 2 weeks. He was intubated one month prior due to a traumatic brain injury. Upper airway USG findings showed irregular air-mucosal interface (AMI) and comet tail artefacts over the 1st and 2nd tracheal ring. A direct laryngoscopy in the operating room showed thick mucopus inferior to the vocal cords, with necrotic tracheal cartilages and debris obstructing the airway. He was successfully treated with parenteral antibiotics, wound debridement and tracheostomy. CONCLUSION: Our case highlights the first documented USG findings of tracheal necrosis. Upper airway USG serves as a potential diagnostic modality in managing the condition.

Point-of-Care Ultrasound: A Vital Tool for Anesthesiologists in the Perioperative and Critical Care Settings.

Point-of-care ultrasound (POCUS) is an essential skill in various specialties like anesthesiology, critical care, and emergency medicine. Anesthesiologists utilize POCUS for quick diagnosis and procedural guidance in perioperative and critical care settings. Key applications include vascular ultrasound for challenging venous and arterial catheter placements, gastric ultrasound for aspiration risk assessment, airway ultrasound, diaphragm ultrasound, and lung ultrasound for respiratory assessment. Additional utilities of POCUS can include multi-organ POCUS evaluation for undifferentiated shock or cardiac arrest, ultrasound-guided central neuraxial and peripheral nerve blocks, focused cardiac ultrasound, and novel applications such as venous excess ultrasound. This review highlights these POCUS applications in perioperative and intensive care and summarizes the latest evidence of their accuracy and limitations.

Efficiency of Simulation-Based Learning Using an ABC POCUS Protocol on a High-Fidelity Simulator.

Critically ill patients with rapidly deteriorating clinical status secondary to respiratory and cardio-vascular compromise are at risk for immediate collapse if the underlying pathology is not recognized and treated. Rapid diagnosis is of utmost importance regardless of the setting. Although there are data to support the use of point-of-care ultrasound in critical patients, there is no consensus about the best educational strategy to implement. We designed a curriculum based on the ABC (Airway, Breathing, Circulation) protocol that covers essential airway, lung, and cardiac ultrasound skills needed for fast diagnosis in critical patients and applied it in high-fidelity simulation-based medical education sessions for anesthesia and intensive care residents year one and two. After theoretical and practical assessments, our results show statistical differences in the theoretical knowledge and above-average results in practical assessment. Our proposed curriculum based on a simple ABC POCUS protocol, with an Airway, Breathing, and Circulation approach, is useful in teaching ultrasound basics regarding airway, lung, and cardiac examination using high-fidelity simulation training to anesthesia and intensive care residents, but further research is needed to establish the utility of Simulation-Based Medical Education in Point of Care Ultrasound in the critical patient.

Applications of Airway Ultrasound for Endotracheal Intubation in Pediatric Patients: A Systematic Review.

Endotracheal intubation is a challenging procedure for pediatric patients. Airway ultrasound as a new technology is suitable for aiding this process, but its diagnostic value remains unclear. We searched MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and the Chinese biomedical literature database to summarize specific applications of airway ultrasound in each step of endotracheal intubation in pediatric patients. Diagnostic accuracy and 95% confidence interval were used as outcomes. In total, 33 studies (6 randomized controlled trials and 27 diagnostic studies) with 1934 airway ultrasound examinations were included. Population included neonates, infants, and older children. Airway ultrasound could be used to determine the endotracheal tube size and confirm endotracheal intubation and intubation depth; the diagnostic accuracy for all these factors was 23.3-100%, 90.6-100%, and 66.7-100%, respectively. Furthermore, the accuracy of airway ultrasound in predicting endotracheal tube size was consistently higher than traditional methods, such as height formula, age formula, and the width of the little finger. In conclusion, airway ultrasound has unique advantages for confirming successful endotracheal intubation in pediatric patients, and it may become an effective auxiliary tool in this field. There is a need to develop a unified airway ultrasound protocol to conduct clinical trials and practice in the future.

Airway ultrasound for patients anticipated to have a difficult airway: Perspective for personalized medicine.

Airway ultrasound allows for precise airway evaluation, particularly for assessing the difficult airway and the potential for front of neck access. Many studies have shown that identification of the cricothyroid membrane by airway ultrasound is more accurate than digital palpation. However, no reports to date have provided clinical evidence that ultrasound identification of the cricothyroid membrane increases the success rate of cricothyroidotomy. This is a narrative review which describes patients with difficult airways for whom airway ultrasound may have been useful for clinical decision making. The role of airway ultrasound for the evaluation of difficult airways is summarized and an approach to the use of ultrasound for airway management is proposed. The goal of this review is to present practical applications of airway ultrasound for patients predicted to have a difficult airway and who undergo cricothyroidotomy.

Airway ultrasound to detect subglottic secretion above endotracheal tube cuff.

BACKGROUND: Subglottic secretion had been proven as one of the causes of microaspiration and increased risk of ventilator-associated pneumonia (VAP). The role of ultrasound to detect subglottic secretion has not yet been established. PURPOSE: The purpose of this study is to determine the sensitivity and specificity of upper airway ultrasound (US) in the detection of subglottic secretions as compared to computed tomography (CT) scanning. MATERIAL AND METHODS: A prospective observational study was carried out in adult trauma patients requiring mechanical ventilation and cervical CT scan. All patients had an endotracheal tube cuff-pressure maintained between 20 and 30 cm H2O. Airway US was performed at the bedside immediately before the patient was transferred to the CT scan suite. The sensitivity, specificity, and positive/negative predictive values (PPV, NPV) of the upper airway US detection of subglottic secretions were then calculated and compared with CT findings. RESULTS: Fifty participants were consecutively included. Subglottic secretions were detected in 31 patients using upper airway US. The sensitivity and specificity of upper airway US in detecting subglottic secretion were 96.7% and 90%, respectively (PPV 93.5%, NPV 94.7%). 18 (58%) patients with subglottic secretions developed VAP during their ICU stay (p = 0.01). The area under the receiver operating curve (AUROC) was 0.977 (95% CI 0.936-1.00). CONCLUSIONS: Upper airway US is a useful tool for detecting subglottic secretions with high sensitivity and specificity. CLINICAL IMPLICATIONS: This study shows: 1. Upper airway US may aid in detecting subglottic secretions, which are linked to VAP. 2. Detecting subglottic secretions at the bedside aids in determining the best frequency of subglottic aspiration to clean the subglottic trachea. 3. Upper airway US may also aid in detecting the correct ETT position. Trial registration Clinicaltrials.gov. CLINICALTRIALS: gov identifier NCT04739878 Date of registration 2nd May 2021 URL of trial registry record https://clinicaltrials.gov/ct2/show/NCT04739878 .

Point-of-Care Ultrasound: A Moving Picture Is Worth a Thousand Tests.

The effective utilization of point-of-care ultrasound may decrease the utilization of conventional diagnostic modalities. This review describes the various pathologies that can be effectively and rapidly identified with point-of-care cardiac, lung, abdominal, vascular airway, and ocular ultrasonography.

Management of an Anticipated Difficult Airway in a Pediatric Patient With Stickler Syndrome.

Stickler syndrome (SS) is a congenital autosomal dominant condition that affects the formation of collagen. Of primary importance to the anesthesia provider is the propensity for difficulties in managing the airway due to orofacial abnormalities associated with this syndrome. The authors present a two-year-old infant with SS who required anesthetic care for a cleft palate repair. The potential anesthetic implications of this syndrome are discussed and the importance of proper planning and preparation and the usefulness of ultrasound as an airway evaluation tool are highlighted.

Useful Ultrasonographic Parameters to Predict Difficult Laryngoscopy and Difficult Tracheal Intubation-A Systematic Review and Meta-Analysis.

Unexpected difficult airway management can cause significant morbidity and mortality in patients admitted for elective procedures. Ultrasonography is a promising tool for perioperative airway assessment, nevertheless it is still unclear which sonographic parameters are useful predictors of difficult laryngoscopy and tracheal intubation. To determine the ultrasonographic predictors of a difficult airway that could be applied for routine practice, a systematic review and meta-analysis was conducted. Literature search was performed on PubMED, Web of Science and Embase using the selected keywords. Human primary studies, published in English with the use of ultrasonography to prediction of difficult laryngoscopy or tracheal intubation were included. A total of 19 articles (4,570 patients) were analyzed for the systematic review and 12 articles (1,141 patients) for the meta-analysis. Standardized mean differences between easy and difficult laryngoscopy groups were calculated and the parameter effect size quantified. A PRISMA methodology was used and the critical appraisal tool from Joanna Briggs Institute was applied. Twenty-six sonographic parameters were studied. The overall effect of the distance from skin to hyoid bone (p = 0.02); skin to epiglottis (p = 0.02); skin to the anterior commissure of vocal cords (p = 0.02), pre-epiglottis space to distance between epiglottis and midpoint between vocal cords (p = 0.01), hyomental distance in neutral (p < 0.0001), and extended (p = 0.0002) positions and ratio of hyomental distance in neutral to extended (p = 0.001) was significant. This study shows that hyomental distance in the neutral position is the most reliable parameter for pre-operative airway ultrasound assessment. The main limitations of the study are the small sample size, heterogeneity of studies, and absence of a standardized ultrasonographic evaluation method [Registered at International prospective register of systematic reviews (PROSPERO): number 167931].

Development of a scoring system for predicting difficult intubation using ultrasonography.

BACKGROUND AND AIMS: Ultrasound measurement of anterior neck soft tissue thickness by skin to epiglottis distance (SED) has been shown to predict difficult laryngoscopy. In this study, we developed an airway scoring system incorporating SED into three clinical predictors and assessed whether it would improve accuracy in prediction of difficult intubation. METHODS: Mentohyoid distance, mandibular subluxation, head extension and ultrasound measurement of skin to epiglottis distance were measured a day before surgery in 310 adult patients. During direct laryngoscopy, Cormack-Lehane grading was noted (Grade 1 and 2 = Easy, Grade 3 and 4 = Difficult). We constructed a score named MSH, which included mentohyoid distance, mandibular subluxation and head extension. Then, SED was added to the MSH score to form another new score named USED-MSH. Student's t-test, Mann-Whitney U test and Chi-square test or Fisher exact tests were used. Both scoring systems were compared under the receiver-operating characteristic curve and area under the curve (AUC) were calculated. RESULTS: Difficult intubation was observed in 62/310 patients (20%). The AUC for USED-MSH score was greater than the MSH score (0.93, 95% CI [0.89-0.97] vs 0.76, 95% CI [0.69-0.84], P value <0.001). USED-MSH score had higher sensitivity (93.6% vs 59.7%) and lower specificity (85.9% vs 91.1%) with similar positive predictive value (62.7% vs 62.4%) in comparison with MSH score. CONCLUSION: An airway scoring system using the ultrasound measurements of skin-to-epiglottis distance along with the clinical predictors would be helpful in the prediction of difficult intubation.

Clinical Audit to Assess Upper Airway Ultrasound Skills in Anaesthesia Trainees.

This audit looks at upper airway ultrasound skills and basic knowledge of anaesthesia trainees. The implementation took place in a District General Hospital in the United Kingdom where upper airway ultrasound is not a part of formal training. Seventeen anaesthetic trainees were given hands-on experience of upper airway ultrasound and were asked to fill in a questionnaire. The result showed a rapid learning curve for assessing cricothyroid membrane localisation, but difficulty in oesophageal identification. A potential plan to improve this skill was proposed and if implemented, will help all trainee anaesthetists in the present and future to develop this skill.

Relationship Between Evaluations of Tracheal Tube Position Using Ultrasound and Fluoroscopy in an Infant and Pediatric Population.

INTRODUCTION: A non-radiographic technique to measure the location of the tracheal tube (TT) in children is of value given the risk of inappropriate TT placement along with concerns about radiation exposure. Airway point-of-care ultrasound (POCUS) has demonstrated utility in children, but the examinations vary by age and may require non-traditional techniques or utilize less common probes. This study evaluated the performance of measuring the tracheal location of the cuffed TT using a novel, linear probe-based POCUS examination over a wide age range of children. After adjusting for the subjects' height and TT size, ultrasound measurements of the TT cuff location were compared with fluoroscopy measurements of the TT tip location. METHODS: Perioperative pediatric patients (<10 years) requiring a cuffed TT were enrolled. After routine TT placement, ultrasound and fluoroscopy images were obtained. Measurements from the TT cuff to the cricoid cartilage were obtained from the POCUS examination. Chest fluoroscopy was reviewed to measure the TT's distance from the carina. Both measurements were then compared after scaling for patient height. The duration of the ultrasound examination and image quality scores were also recorded. RESULTS: Forty-one patients were enrolled, with a median age of 3 (25th/75th percentile: 1.50/7.00) years. The POCUS examination identified the TT cuff in all cases with the highest image quality score. The median POCUS exam time was 112 (25th/75th percentile: 80.00/156.00) seconds. There was a strong correlation between the POCUS measurements and the fluoroscopy measurements, r = -0.7575, 95% CI [-0.8638, -0.5866 ], p < 0.001). CONCLUSIONS: Our results demonstrate a strong correlation between POCUS TT localization measurements and traditional measurements via fluoroscopy. This study further supports the utility of POCUS for pediatric care.

Novel role of focused airway ultrasound in early airway assessment of suspected laryngeal trauma.

BACKGROUND: Upper airway injury secondary to blunt neck trauma can lead to upper airway obstruction and potentially cause a life-threatening condition. The most important aspect in the care of laryngeal trauma is to establish a secure airway. Focused airway ultrasound enables recognition of important upper airway structures, offers early opportunity to identify life-threatening upper airway injury, and allows assessment of the extent of injury. This information that can be obtained rapidly at the bedside has the potential to facilitate rapid intervention. CASE PRESENTATION: We report a case series that illustrate the diagnostic value of focused airway ultrasound in the diagnosis of laryngeal trauma in patients presenting with blunt neck injury. CONCLUSION: Early recognition, appropriate triaging, accurate airway evaluation, and prompt management of such injuries are essential. In this case series, we introduce the potential role of focused airway ultrasound in suspected laryngeal trauma, and the correlation of these exam findings with that of computed tomography (CT) scanning, based on the Schaefer classification of laryngeal injury.

Pre-extubation ultrasonographic measurement of intracricoid peritubal free space: A pilot study to predict post-extubation airway obstruction in children.

OBJECTIVE: Post-extubation airway obstruction (PEAO) is common and difficult to predict in children. We hypothesized that Intracricoid Peritubal Free Space (IPFS) obtained by deducting the outer diameter of the endotracheal tube in situ (ODTT - provided by the manufacturer) from the ultrasonographically measured internal transverse cricoid diameter (ICDt) is likely to be inversely proportional to the risk of developing PEAO. This prospective observational study was planned to evaluate this hypothesis. METHODS: This study was conducted in a Pediatric Intensive Care Unit of a tertiary care teaching hospital in a low-middle income economy. Laryngotracheal ultrasound was performed just prior to the first elective extubation in 93 patients (3mo-12yrs) intubated for ≥ 48 h, to calculate the IPFS. Patients with pre-existent upper airway conditions, chronic respiratory diseases and poor airway reflexes were excluded. Patients with Westley's Croup Score (WCS) ≥4 were classified as PEAO, and those with WCS ≥7, as extubation failure (EF). RESULTS: Thirty-two (34%) patients developed PEAO, while seventeen (18%) developed EF. Baseline clinical characteristics were similar in patients with and without PEAO. IPFS was lesser in patients who developed PEAO (4.16 ± 1.18 mm vs. 5.28 ± 1.51 mm, p < 0.001) and EF (4.13 ± 1.44 mm vs. 5.07 ± 1.46 mm, p = 0.019) compared to those who did not. IPFS <5.16 mm predicted PEAO [sensitivity, 84%; positive predictive value (PPV), 87%; AUC, 0.714), while IPFS <3.77 mm predicted EF (specificity, 80%; PPV, 88%; AUC, 0.679). Combining clinical risk factors (presence of clinical edema, prolonged ventilation and younger age) and lesser IPFS helped develop a clinico-sonographic prediction model with improved predictability for PEAO and EF (AUC, 0.820 for both). CONCLUSIONS: Lesser IPFS is reasonably sensitive and specific to predict PEAO and EF respectively with high PPV. Combining clinical risk factors and IPFS improved the PPV further. Further studies with larger samples stratified for different age groups in different clinical settings are required to confirm these observations.

Differences Between Esophageal and Tracheal Intubation Ultrasound View Proficiency: An Educational Study of Novice Prehospital Providers.

Objectives Airway ultrasound is now possible in the prehospital setting due to advances in ultrasound equipment portability. We questioned how well prehospital providers without prior experience could determine both esophageal and tracheal placement of an endotracheal tube in cadavers after a brief training course in ultrasound.  Methods This educational prospective study at the Simulation Center in Mayo Clinic Jacksonville Florida enrolled 50 prehospital providers. Demographic and practice background information was obtained through surveys. Each participant performed a baseline ultrasound to determine endotracheal tube placement in a cadaver that was randomly assigned to an esophageal or tracheal intubation. Participants then repeated the randomized testing after a 15-minute tutorial. Before and after overall accuracy as well as proportions of correct identification of esophageal and tracheal intubations were determined and compared using standard binomial proportion and McNemar's tests. Results  None of the participants had prior experience of performing airway ultrasound. Baseline group scores were 60% (CI 45%-74%) for overall accuracy (n=50), 55% (CI 32%-76%) for correct identification of an esophageal intubation, and 64% (CI 44%-81%) for correct tracheal detection. Baseline scores were not significantly different from standard binomial distributions. Post-test scores were 82% (CI 69%-91%) for overall accuracy, 96% (CI 80%-100%) for esophageal intubation detection, and 66.7% (CI 45%-84%) for tracheal intubation detection, with corresponding binomial p-values of <0.001, <0.001, and 0.15. P-values for McNemar's paired test for combined overall accuracy, correct esophageal detection, and correct tracheal detection were 0.04, 0.02, and 0.62, respectively. Conclusions Prehospital participants without prior ultrasound experience demonstrated significant gains in airway ultrasound proficiency after a limited introductory course. Post-training score increases were largely due to a notable increase in correct esophageal intubation detection rates. Learners did not make significant progress in correctly identifying a tracheal intubation. Airway ultrasound educational design may benefit from added emphasis on the potentially more difficult to recognize tracheal intubation view.