A Novel Articulating Stylet for Improving First-Pass Intubation Success

SUMMARY Endotracheal intubation (ETI) is performed for surgery under general anesthesia, and to provide oxygen during cardiac arrest and respiratory failure. To perform this procedure, medical personnel use both hands: the left hand inserts a laryngoscope to provide visualization, and the right hand maneuvers the endotracheal tube (ETT) into the patient’s airway. Most often, the ETT is preloaded with a stylet device to help guide the ETT through the curving airway path and into the trachea. However, there can be complications if the pre-formed curve of the stylet does not correspond to the anatomical curve of the patient. Common patient characteristics including obesity, a short, thick or immobile neck, small mouth, or receding chin, especially in combination, may require multiple attempts. In emergency situations multiple attempts can exacerbate physiologic co-morbidities such as hypotension or hypoxia. Multiple large studies have established that inability to intubate on the first attempt is strongly correlated with patient injury. In aggregate, difficult intubation and resultant patient injuries account for over $1B excess costs in the U.S. annually. Visualization has undergone a tremendous technological advance, thanks to video laryngoscopy, but improvement in steering the ETT has lagged behind. SmartAirway addresses this issue with an innovative, articulating stylet, the SmartStylet, that can be adjusted to the patient’s internal airway curvature by the operator in real time to promote first-pass intubation success. Using a uniquely designed spring-steel mechanism, the proposed device is able to flex an onboard, standard, off-the-shelf ETT 60 degrees anteriorly and 15 degrees posteriorly, while in the body and using just one hand. Stylets on the market today only allow for adjustments of the device after interrupting the procedure, removing the styletted ETT, and re- bending it outside the body. Then the entire procedure is repeated. While our working prototype has demonstrated its ability to flex and adjust the ETT’s shape during intubation on a manikin, there is further testing needed before it can be produced and used by healthcare providers. The proposed work in this Phase I proposal will accelerate this through the following aims: 1) Mechanical optimization of the SmartStylet by minimizing the hand-grip force required to flex the tube through enhanced leverage, coating the moving parts with lubricating materials used in stylets today, and other possible design enhancements and mechanical testing, and 2) Demonstration of device efficacy and expected superiority compared to the two most commonly used stylets in clinical practice in a preclinical study in the hands of anesthesiology residents and fellows using a manikin model under routine and difficult set-ups. The inability to properly steer the ETT contributes to the majority of failed intubation attempts, and is due to the limitations of current devices; our device directly addresses this technology gap. The adoption of the SmartStylet has the potential to significantly decrease the number of attempts and complications associated with difficult intubation, improve patient outcomes, and decrease healthcare costs.