A simulated 'can't intubate, can't oxygenate' manikin crossover study investigating a modified front-of-neck access airway device

A 'can't intubate, can't oxygenate' (CICO) situation is an uncommon and time-critical emergency. Many institutions have adopted a 'scalpel-bougie-endotracheal tube (ETT)' technique based on evidence produced by the 4th National Audit Project of the Royal College of Anaesthetists and 2015 Difficult Airway Society guidelines. We made a modification to the traditional 'scalpel-bougie-ETT' technique, using a shortened bougie and replacing the ETT with a cuffed Melker airway in a preassembled device (called 'Secure Airway for Front-of-neck Emergencies' (SAFE airway device)), which we felt might reduce cognitive load on a single operator in an emergency CICO situation. We then performed a simulation crossover study using 20 volunteer anaesthetic doctors to compare this modification with the traditional technique. After a standardised pre-recorded video demonstration, participants performed simulated tube insertion using both the standard 'scalpel-bougie-ETT' technique and the SAFE airway device in randomised order. Participants were filmed for accurate timestamping. The primary outcome was time to successful tube insertion while secondary outcomes included number of attempts and ease of insertion. Overall time to cuff inflation was shorter, statistically and practically, with the SAFE airway device compared with the ETT (median 30 vs. 52 seconds, P < 0.001). Twenty-five percent of participants required multiple attempts using the ETT method versus 5% using the SAFE airway device, which was also rated as being easier to use. This study demonstrates that the SAFE airway device was fast, effective, easy to use and acceptable to airway practitioners in a simulated manikin environment. These findings indicate that further studies of the SAFE airway device are warranted.

Modelling and Manufacturing of a 3D Printed Trachea for Cricothyroidotomy Simulation

Cricothyroidotomy is a life-saving medical procedure that allows for tracheal intubation. Most current cricothyroidotomy simulation models are either expensive or not anatomically accurate and provide the learner with an unrealistic simulation experience. The goal of this project is to improve current simulation techniques by utilizing rapid prototyping using 3D printing technology and expert opinions to develop inexpensive and anatomically accurate trachea simulators. In doing so, emergency cricothyroidotomy simulation can be made accessible, accurate, cost-effective and reproducible.

Three-dimensional modelling software was used in conjunction with a desktop three-dimensional (3D) printer to design and manufacture an anatomically accurate model of the cartilage within the trachea (thyroid cartilage, cricoid cartilage, and the tracheal rings). The initial design was based on dimensions found in studies of tracheal anatomical configuration. This ensured that the landmarking necessary for emergency cricothyroidotomies was designed appropriately. Several revisions of the original model were made based on informal opinion from medical professionals to establish appropriate anatomical accuracy of the model for use in rural/remote cricothyroidotomy simulation.

Using an entry-level desktop 3D printer, a low cost tracheal model was successfully designed that can be printed in less than three hours for only $1.70 Canadian dollars (CAD). Due to its anatomical accuracy, flexibility and durability, this model is great for use in emergency medicine simulation training. Additionally, the model can be assembled in conjunction with a membrane to simulate tracheal ligaments. Skin has been simulated as well to enhance the realism of the model. The result is an accurate simulation that will provide users with an anatomically correct model to practice important skills used in emergency airway surgery, specifically landmarking, incision and intubation. This design is a novel and easy to manufacture and reproduce, high fidelity trachea model that can be used by educators with limited resources.