Training mannequins are a traditional component of intubation practice and are helpful for going through the mechanics of a given airway technique. In a mannequin, however, the tongue and the epiglottis, molded and semi-rigid in structure, are distinctly separated from the posterior pharynx. The epiglottis is suspended anteriorly and superiorly away from the laryngeal inlet. Even before the laryngoscope is inserted, the tongue and epiglottis, the two structures central to laryngoscopy, do not behave as they do in a real person with no muscular tone. Identifying laryngeal structures and controlling the tongue and epiglottis on a mannequin is not a challenge.
Along with the mechanical and visual limitations of mannequins, most institutions provide trainees with practice on only one type of intubation trainer. This fosters a very limited understanding of anatomy and mechanical variation encountered in actual patients. As shown by Plummer, Owen and Parry from Flinders University of South Australia, mannequin training is best done using several different types of airway trainers:
Plummer JL, Owen H. Learning endotracheal intubation in a clinical skills learning center: a quantitative study. Anesth Analg. 2001; 93: 656-62.
Parry K, Owen H. Small simulators for teaching procedural skills in a difficult airway algorithm. Anaesth Intensive Care. 2004; 32: 401-9.
Although airway trainers have been used for many decades, it is only with the recent production of AirSim trainers by TruCorp (www.trucorp.co.uk/) that an airway trainer was modeled directly from actual human anatomy. These trainers were developed by the Department of Anaesthetics at Queen´s University, Belfast, UK. Most trainers are snapped together pieces of plastic or rubber made to approximate human dimensions. TruCorp used imaging from three-dimensional CT scanning and a special forming process to create a unique one-piece, upper aerodigestive tract. The result is a much more visually realistic trainer than previously available. TruCorp now makes models that have a full nasopharynx and also a bronchoscopy model that goes to down to 4th generation bronchi. A pediatric airway trainer from TruCorp should be available soon.
Airway Cam is a distributor of the full line of TruCorp trainers and also provides rentals.
CLICK HERE TO BUY OR RENT TRUCORP TRAINERS
Simulators in which the tongue gets expanded, the jaws clenched, and other types of artificially “difficult airways” generally have limited clinical value for improving task performance in actual patients. These types of trainers may be useful for algorithm training where the goal is to push the trainee to adopt an alternative approach, but the risk is that the trainee gets the wrong message. Creating “difficult airways” in this manner for laryngoscopy teaches operators to use excessive force and in most mannequins the mechanics are also flawed; for example, plunging in and out works well in a mannequin but does very poorly in real human tissue. Most “difficult airways” are not so difficult as mismanaged, and most are ultimately (often quickly) intubated by a more experienced person using the exact same instrument as that which failed for initial operator. The goal of task training with mannequins (with a laryngoscope or any instrument) should be to practice simple mechanics, i.e., how to grip the device, maneuver the tube, etc., along with the visual and optical challenges of laryngeal visualization and tube delivery.