Difficult tracheal intubation using the Airway Scope in a patient with unexpected mouth-opening difficulty

Abstract

Some reports show that the Airway Scope facilitates tracheal intubation in patients with difficult airways [1‐3]. We report a difficult tracheal intubation using the Airway Scope in a patient with unexpected mouth-opening and laryngoscopic difficulty. A 37-year-old woman, 161 cm in height and weighing 55 kg, underwent ovarian resection under general and epidural anesthesia. (Written informed consent was obtained from the patient to publish this report.) The patient was diagnosed with mild asthma and hypertension, with no medicine prescribed. She had been treated with a mouthpiece from 16 years ago until 5 years ago because of temporomandibular joint (TMJ) disorder. Physical examination before anesthesia showed that the Mallampati score was class 1 and the width of mouth opening was more than two fingerbreadths. Anesthesia was induced with 100 mg propofol. Neuromuscular blockage was monitored with the TOF-Watch during anesthesia. After administering 30 mg rocuronium, waning of thenar muscle contraction and a TOF count of 0 were observed. Continuous infusion of remifentanil was started at a speed of 0.27 lg/kg/min. The patient showed restricted mouth opening of one fingerbreadth. Jaw movement within this breadth was straightforward, but we did not apply a jaw thrust maneuver. Direct laryngoscopy with Macintosh laryngoscopy was difficult, and the Cormack‐ Lehane view was grade IV even after administering 10 mg additional rocuronium. The blade of the Airway Scope could not be advanced into the mouth. Finally, tracheal intubation was successful using the Trachlight. The operation was completed without problems. The patient could voluntarily open her mouth to 30 mm 3 h after the operation.