What anesthetic techniques are appropriate for patients undergoing laser laryngoscopy?
The caveat to anesthesia for laser laryngoscopy is to supply a gas mixture with the lowest potential for com-bustion. Nitrous oxide (N2O) is as combustible as oxygen. Preferable mixtures include air–oxygen, or helium–oxy-gen. Compared with nitrogen, helium possesses a higher thermal conductivity, predisposing to delayed ignition of the endotracheal tube by several seconds. Theoretically, helium’s lower density will allow for less turbulent flow and lower resistance to flow through smaller endotracheal tubes. The ANSI recommends against using volatile anes-thetics during laser airway surgery because they decom-pose into potentially toxic compounds when exposed to airway fires. Positive pressure ventilation can be provided without an endotracheal tube by employing a Sanders Venturi system. Ideally, the lowest inspired oxygen concentration required to safely oxygenate the patient should be used. Total intravenous anesthesia with propo-fol, remifentanil, or alfentanil might be preferred in most cases.
An immobile surgical field is necessary to ensure precise laser therapy. Even the slightest motion of the vocal cords may result in improper laser therapy. Despite its controver-sies, a succinylcholine infusion with precise train-of-four monitoring may deliver the intense neuromuscular blockade needed for this precise surgery.