Introduction: Cricothyrotomy is an intervention performed to salvage “can't intubate, can't ventilate” situations. Studies have shown poor accuracy landmarking the cricothyroid membrane, particularly in female patients by surgeons and anesthesiologists. There is less data available about emergency physician performance. This study examines the perceived versus actual success rate of landmarking the cricothyroid membrane by resident and staff emergency physicians using obese and non-obese models. Methods: Five male and female volunteers were selected as models. Each model was placed supine, and a point-of-care ultrasound expert landmarked the borders of each cricothyroid membrane. 20 residents and 15 staff emergency physicians were given one attempt to landmark five models. Data was gathered on each participant's perceived likelihood of success and attempt difficulty. Overall accuracy and accuracy stratified by sex and obesity status were calculated. Results: Overall landmarking accuracy amongst all participants was 58% (SD 18%). A difference in accuracy was found for obese males (88%) versus obese females (40%) (difference = 48%, 95% CI = 30-65%, p < 0.0001); and non-obese males (77%) versus non-obese females (46%) (difference = 31%, 95% CI = 12-51%, p = 0.004). There was no association between perceived difficulty and success (correlation = 0.07, 95% CI=−0.081-0.214, p = 0.37). Confidence levels overall were higher amongst staff physicians (3.0) than residents (2.7) (difference = 0.3, 95% CI = 0.1-0.6, p = 0.02), but there was no correlation between confidence in an attempt and its success (p = 0.33). Conclusion: We found that physicians demonstrate significantly lower accuracy when landmarking cricothyroid membranes of females. Emergency physicians were unable to predict their own accuracy while landmarking, which can potentially lead to increased failed attempts and longer time to secure the airway. Improved training techniques and a modified approach to cricothyrotomy may reduce failed attempts and improve the time to secure the airway.

Introduction: The cricothyroid membrane is used as a landmark for emergent surgical airway access. Ultrasound identification of the cricothyroid membrane is more accurate than landmarking by palpation. The objective of this study was to determine whether head of bed elevation affects the position of the cricothyroid membrane as identified by ultrasound. Methods: This was a prospective, observational study on a convenience sample of adult patients presenting to the emergency department. Participants underwent ultrasound scans by trained physicians at 0, 30 and 90 degrees head of bed elevation to identify the cricothyroid membrane. The cricothyroid membrane position identified at 0 degrees was used as a reference, and the change in position of the external landmark of the cricothyroid membrane with the patient at 30 and 90 degrees was measured. Additionally, the patients gender, age, body mass index (BMI) and Mallampati score were recorded for comparison. Linear mixed effects models with 95% confidence intervals were used to determine the effect of head of bed elevation, age, BMI and Mallampati score on the differences between measured distances. Results: One hundred and two patients were enrolled in the study. The average change in position from reference was statistically significant for both 30 degrees [2.72±0.77mm (p<0.01)] and 90 degrees [4.23±0.77mm (p<0.01)] head of bed elevation. The adjusted linear mixed effects model showed age greater than 70, BMI over 30 and higher Mallampati score were associated with greater change in distance between cricothyroid membrane landmarks. Conclusion: There was a statistically significant difference in the position of the cricothyroid membrane comparing 0 degrees to 30 and 90 degrees head of bed elevation. However, the relatively small differences suggest that this finding is not clinically relevant. Further study is required to evaluate if these differences impact the actual successful performance of cricothyrotomy.

Introduction: In confined-space airway emergencies, prehospital personnel may need to perform cricothyrotomy when conventional airway techniques cannot be utilized or have failed. This study is a prospective, cross-over, randomized controlled trial that compares two widely-known techniques using two commercially available kits.

Methods: Twenty residents at Palmetto Health Richland Department of Emergency Medicine participated in the study. Their performance was assessed using the time required to placement and correctness of placement for each device. The residents performed the procedures on an Air-Man™ manikin that had been situated in a confined space. The residents also indicated which kit they would prefer in a confined-space, emergency airway situation.

Results: All of the devices were placed in the airway. The mean time to placement for the Melker™ and Quicktrach™ kits was 108.5 seconds and 23.9 seconds, respectively. This yielded a mean difference of 84.5 seconds, which provided a t-statistic of 8.88 (p < 0.0001). There was no evidence of a carry-over effect (p = 0.292) or a period effect (p = 0.973). All residents preferred using the Quicktrach™ kit.

Conclusions: Use of the Quicktrach™ kit resulted in the fastest time to placement, was placed correctly in the airway, and was preferred by each of the residents. Its small, simple, and sturdy design, with few parts and easy manipulation, allow the Quicktrach™ to be a valuable option in prehospital situations involving confined spaces. The Melker™ kit, with its many parts, and need for greater manipulation, is not as easily utilized or preferred in a confined space scenario.

The indications for the ruling for the Gulf Forces that emergency cricothyrotomy is to be performed where the airway is thought to be compromised are reviewed. The advantages of this procedure are outlined and some of the likely consequences regarding the incidence of complications and their management predicted.