Point-of-Care Ultrasound: Novel Technology to Routine Perioperative Assessment Tool

A Porcine Model for Learning Ultrasound Anatomy of the Larynx and Ultrasound-Guided Cricothyrotomy

BACKGROUND

Difficulty with tracheal intubation is the most common cause of serious adverse respiratory events during anesthesia. Cricothyrotomy is a life-saving procedure that is seldom performed by anesthesiologists. Anesthesiology residents are traditionally trained to perform cricothyrotomy with artificial mannequins and exposed larynx models from animals. These models lack the tissue feel of performing a cricothyrotomy on a patient with difficult neck anatomy. To improve the training experience, we developed a novel training model for cricothyrotomy using a porcine larynx, which incorporates ultrasonographic examination to identify the cricothyroid membrane, and permits varying degrees of difficulty.

METHODS

Twenty-five residents were enrolled in a training curriculum consisting of (1) preprocedure training modules, (2) preprocedure hands-on demonstrations, and (3) three separate cricothyrotomy procedures using a porcine trachea. The first two procedures consisted of residents performing an open and a percutaneous cricothyrotomy on a model, which consisted of porcine trachea with chicken skin pinned over the larynx. The third procedure involved performing an open cricothyrotomy on a more challenging model, constructed by placing several layers of bacon fat between the larynx and chicken skin, making digital palpation of the laryngeal landmarks impossible. Before performing the procedure, residents located the cricothyroid interval with ultrasound. A postcurriculum survey was administered.

RESULTS

Twenty-three of 25 residents were able to perform the open cricothyrotomy by digital palpation on the airway model on the first attempt. With the more challenging model, all 25 residents were able to locate the cricothyroid membrane by ultrasound and successfully perform open and percutaneous cricothyrotomy. Participants felt that they learned new information regarding ultrasound identification of laryngeal anatomy and gained valuable procedural experience in this training exercise.

CONCLUSIONS

Use of the porcine trachea with overlying animal skin and fat provides an effective partial-task trainer for open and percutaneous surgical airway education and lends itself to integration of ultrasound imaging for real-time identification of laryngeal and tracheal anatomy.

POCUS in perioperative medicine: a North American perspective

Ultrasound (US) performed at the point of care has found fertile ground in perioperative medicine. In the hands of anesthesiologists, transesophageal echocardiography (TEE) has become established as a powerful diagnostic and monitoring tool in the perioperative care of cardiac and non-cardiac patients. A number of point-of-care US (POCUS) applications are relevant to perioperative care, including airway, cardiac, lung and gastric US. Although guidelines exist to define the scope of practice for basic and advanced TEE, there remains a lack of such guidelines for perioperative point-of-care ultrasound (POCUS), despite a number of recent calls for action in the academic anesthesia community. POCUS training has been integrated into anesthesia residency curricula in Canada and the United States of America (USA). However, a nation-wide curriculum is still lacking. Many limitations to the development of perioperative POCUS curricula exist, including the need to define the scope of practice and design integrated longitudinal learning approaches. The main anesthesiologist societies in both the USA and Canada are promoting the development of guidelines and have introduced POCUS courses into their national conferences. Although bedside US imaging has been integrated into the curricula of many medical schools in North America, the need for specific national guidelines for the training and practice of POCUS in the perioperative setting by anesthesiologists is crucial to the further development of POCUS in perioperative medicine.