A review of hemodynamic response to the use of different types of laryngoscopes

Abstract

Endotracheal intubation is the gold standard in airway management either as a means to administer general anesthesia or for mechanical ventilation in critically ill patients for protecting the airway when the airway reflexes are dysfunctional. Macintosh laryngoscope is the standard laryngoscope used for intubation though advances in science have resulted in development of laryngoscopes of different designs. The process of laryngoscopy and intubation (L&I) can result in significant hemodynamic response and this is a topic of debate and research in anesthesia. A comprehensive review of hemodynamic responses to various laryngoscope designs has been undertaken here. Tracheal intubation contributes to more hemodynamic response compared to laryngoscopy alone. The hemodynamic responses to L&I are exaggerated in the elderly and those with uncontrolled hypertension. Orotracheal intubation causes less hemodynamic response as compared to nasotracheal intubation. Laryngoscope design, duration of L&I and the forces applied on the laryngoscope all contribute to hemodynamic fluctuations. McCoy blade and videolaryngoscopes where L&I can be performed without the aid of stylets provide better attenuation of hemodynamic response compared to intubation using the Macintosh laryngoscope. Fibreoptic orotracheal intubation with the aid of combined lingual traction and jaw thrust maneuver provides superior attenuation of hemodynamic response compared to use of laryngoscope.