The Pentax-AWS for airway obstruction after tracheal extubation

Abstract

We report two cases of airway obstruction occurring after tracheal extubation, in which the cause of airway obstruction could immediately be confirmed, and re-intubation carried out, using the Pentax-AWS videolaryngoscope (Pentax, Tokyo, Japan). In the first, a middle-aged woman was scheduled for laparoscopic cholecystectomy. After induction of anaesthesia and neuromuscular blockade, the trachea was intubated. At the end of uneventful operation, 50 mg flurbiprofen axetil, a non-steroidal anti-inflammatory drug, was injected intravenously. The trachea was extubated after the patient regained consciousness and responded to verbal command. Shortly later, she complained of dyspnoea and acute airway obstruction occurred. A laryngeal mask airway was inserted while a new tracheal tube was being prepared, but obstruction continued. As rashes had appeared on her chest wall, anaphylactic reaction to the non-steroidal anti-inflammatory drug was suspected. While treatment was being started for possible anaphylaxis, the laryngeal mask was removed and the Pentax-AWS inserted, to observe the upper airway. Oedema of the glottis was confirmed on the videoscreen. The trachea was re-intubated, by advancing a tracheal tube which was attached to the Pentax-AWS. In the second case, a middle-aged man was scheduled for laryngomicrosurgery. After uneventful induction of anaesthesia and tracheal intubation, the surgeons resected laryngeal tumour without difficulty and reported that there was no oedema or bleeding. The trachea was extubated after the patient had regained consciousness and responded to verbal command. Immediately after this, airway obstruction occurred and arterial haemoglobin oxygen saturation decreased to 70%. Insertion of the Pentax-AWS showed that the supraglottic area was now grossly oedematous. A tracheal tube which was attached to the Pentax-AWS was advanced into the trachea. In both cases, the trachea was extubated uneventually the next day. The shape of the Pentax-AWS blade is based on oropharyngeal anatomy, thus there is no need to place the patient’s head and neck to the ‘sniffing’ position, and little force is required to see the glottis [1, 2]. Consequently, insertion of the Pentax-AWS should be less stressful than with the Macintosh blade in awake patients. The videoscreen of the Pentax-AWS enables one to clearly see the cause of upper airway obstruction. In addition, because a tracheal tube is already attached to Pentax-AWS, it is possible to intubate the trachea immediately after confirming the cause of airway obstruction. We believe that the Pentax-AWS is potentially useful in patients with airway obstruction after tracheal extubation, when there is not enough time to give sedatives or local anaesthetics for insertion of a Macintosh laryngoscope, or to carry out fibreoptic intubation.