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October 13, 2012
8:00:00 AM - 11:00:00 AM
Room Hall C-Area E
Lightly Preserved Cadavers or Accelerated Training of Critical Care Medicine Fellows in Airway Management
John P. Henao, M.D., Steven Orebaugh, M.D., Samuel Tisherman, M.D., P. Roolf, M.D., Eugene Myers, M.D., James V. Snyder, M.D.
University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, United States


Simulation has been shown to improve airway management skills for inexperienced physicians (1). With use of unembalmed cadavers for accelerated airway training, we found that critical care fellows who were airway novices had high initial intubation success rates in emergent intubations. However, the length of time that unpreserved specimens may be used as teaching tools is limited by tissue decomposition as well as the risk of infection despite screening. Therefore, we assessed required modifications for airway training when using cadavers infused with a “light” embalming formula.

Methods: Five lightly preserved cadavers were evaluated, both before and after a series of structural alterations, for 1) Realistic simulation of direct laryngoscopy (DL) with axial (cervico-thoracic) manipulation in visualizing the glottic opening, expressed as percent of glottic opening (POGO) (2); 2) Authenticity of the response of the epiglottis to a position of the laryngoscope blade tip on or near the hyoepiglottic ligament (HEL) during DL; and, 3) Simulation of bag-mask ventilation techniques. Structural alterations of the specimens to improve the realism of simulation are noted in Table 1.

Results: 1.) Glottic visualization: Preservation allowed very limited exposure of the glottis during DL in only one of five specimens. Transoral glossal reduction improved exposure in all, and allowed glottic exposure during DL in four of the cadavers. SHL section allowed a POGO of 100 in four and 70 in the fifth. Altering tension of the simulated SHL permitted adjustment of the POGO view at DL. 2). Epiglottic response: In all

specimens, rigidity of the epiglottis and its pharyngeal moorings led to an

unrealistic epiglottic elevation with blade lift on the posterior tongue, or

anywhere in the valecula, requiring a section of the glosso-epiglottic

ligaments to “free” the epiglottis, and allow it to drop to its normal

position. This restored the leveraging effect of blade tip pressure on the HEL to create brisk elevation of the epiglottis. 3.) SHL Simulation: The simulated SHL allowed alteration of tension experienced during DL, to compensate for tissue laxity created during repeated attempts by trainees. 4.) Mask Ventilation: Teaching mask techniques in these preserved specimens was impaired by reduced skin elasticity. Tissue rigidity favored airway patency, and the lack of tongue mobility prevented typical obstruction of the posterior pharynx, such that jaw thrust and cervico-thoracic flexion were usually not required to provide effective ventilation. Restoration of the facial contours with tissue builder injections improved mask seal and simulated mask ventilation.

Conclusion: This cadaver model lends itself to teaching a variety of different airway interventions including bag-mask ventilation, assistance of spontaneous ventilation, and direct laryngoscopy. Structural alterations of the specimens permits more realistic simulation of the airway and adjustment of the degree of difficulty of DL.

Figure 1

Copyright © 2012 American Society of Anesthesiologists