Severe bradycardia during suspension laryngoscopy performed after tracheal intubation using a direct laryngoscope with a curved blade -A case report-

Abstract

There are a few reports about bradycardia or asystole caused by direct laryngoscopy. However, we encountered severe bradycardia in response to suspension laryngoscopy for laryngeal polypectomy after safely completing tracheal intubation using a direct laryngoscope with a curved blade. The tip of the curved blade of the direct laryngoscope is positioned at the vallecula (between the base of the tongue and the pharyngeal surface of the epiglottis) during tracheal intubation, while the blade tip of the suspension laryngoscope lifts the laryngeal surface of the epiglottis or supraglottic area during surgery. Therefore, suspension laryngoscopy can be said more vagotonic than curved-blade direct laryngoscopy. Because of the possibility of bradycardia induced by suspension laryngoscopy, clinicians must be careful about severe bradycardia even after safely completing intubation using direct laryngoscopy.

Intraoperative cardiac arrest etiologies in head and neck surgery: A comprehensive review

“…The alternative explanation involves direct vagal stimulation. Glossopharyngeal sensory nerve fibers innervate the pharynx, whereas the internal branch of the superior laryngeal nerve (a sensory branch of the vagus nerve) innervates the laryngeal surface of the epiglottis . The laryngoscope could stimulate the latter branch by mechanical irritation of the exposed laryngeal epiglottic surface during suspension.…”

“…The laryngoscope could stimulate the latter branch by mechanical irritation of the exposed laryngeal epiglottic surface during suspension. In turn, efferent parasympathetic vagal signaling could lead to downstream bradycardia/asystole …”

“…The first case was a resection of a true vocal fold lesion in a patient with well‐controlled hypertension . The second case was a laryngeal polypectomy in a patient with no preexisting cardiac disease . The third case involved tracheal dilation for subglottic stenosis in a patient with a history of coronary artery disease and cardiac stent placement .…”

“…Administration of i.v. atropine or glycopyrrolate before suspension prevented bradycardia allowing for the procedures to be completed . Importantly, the authors of the first case noted that placement of the laryngoscope on the laryngeal surface of the epiglottis without significant tension did not trigger bradycardia.…”

Asystole During Airway Manipulation in Neurosurgical Patient:Causes and Management

“…The remainder of the intraoperative course was uneventful. diovascular changes during airway manipulation but all these were reported in non-neurosurgical procedures [4][5][6][7]. Most of the procedures were related to micro-laryngeal surgery and suspension laryngoscopy.…”