Application of incremental sevoflurane concentration approach in the strategy selection of patients with suspected difficult airway caused by laryngopharyngeal lesions: an observational study

Abstract

Objective To observe the application of incremental sevoflurane concentration approach in the strategy selection of patients with suspected difficult airway caused by laryngopharyngeal lesions. Methods Patients [American Society of Anesthesiologists(ASA) Ⅰor Ⅱ] who underwent laryngopharyngeal surgery under general anesthesia with difficult airway risks from May 2014 to May 2018 were enrolled. The risk factors included degree Ⅰ to Ⅱ laryngeal obstruction or without symptoms of laryngeal obstruction but with the presence of laryngeal neoplasms which occluded more than 1/2 of the glottis through preoperative electronic laryngoscopy. All the enrolled patients were inhaled, sevoflurane, and airway assessment was performed and recorded from grades 1 to 3 when the sedation level reached 5 Ramsay score. All the patients at grades 2 or 3 were the formal participates and then these 110 patients were randomly divided into a fast induction group and a slow induction group (n=55). Intravenous anesthetics and muscle relaxants were used for intubation in the fast induction group, while incremental concentrations of sevoflurane were inhaled for intubation in the slow induction group without muscle relaxants. Both groups were compared for the intubation tool selection, intubation times, duration of intubation, successful rate and the incidence of hypoxic events during intubation. Results Compared with the fast induction group, the slow induction group showed a higher successful rate of one-time intubation, shorter intubation time and a lower incidence of hypoxia(P<0.05). Conclusions Incremental sevoflurane concentration approach is a relatively satisfactory tracheal intubation strategy for patients with suspected difficult airway caused by laryngopharyngeal lesions. Key words: Anesthesia; Induction of anesthesia; Endotracheal intubation; Laryngopharyngeal lesions; Difficult airway