Airway management for tracheal stent insertion in a patient with difficult airway
A 56 year old, 45 kg male patient developed progressively worsening dyspnea after having undergone chemotherapy for non-small cell carcinoma of trachea. On examination, the patient was in respiratory distress with inspiratory stridor and marked bilateral wheezing. Upper airway was assessed to be normal with a Mallampati Class II. Bronchoscopic examination revealed a tight stricture getting intermittently blocked by inflammation and secretions. Patient was scheduled for interventional bronchoscopy with insertion of Dumon Y – stent across the stenotic trachea. The limbs of the Y would be inserted into left and right main bronchus while the long stem would remain in the trachea across the stricture.\nAfter premedication with glycopyrrolate 0.2 mg IM, anaesthesia was induced with fentanyl 2 μg/kg and sevoflurane 5-8% in oxygen (O2). However, direct laryngoscopy revealed a difficult airway (Cormack Lehane Grade III) and it was not possible to introduce the rigid bronchoscope. As visualization of glottic opening was not possible by direct laryngoscopy the fiberoptic bronchoscope (FOB) (nasal route) was used to guide the ventilating bronchoscope tip into laryngeal inlet []. After passage of the rigid bronchoscope anaesthesia was maintained with sevoflurane in O2 with spontaneous respiration by attaching a Mapleson D Circuit to the side arm of the ventilating bronchoscope [].\nThe FOB was then inserted via the rigid bronchoscope to examine the trachea-bronchial tree and adjust the tip of the rigid bronchoscope above the stricture. However, ventilation became inadequate and ETCO2 increased from 35 mmHg to 50 mmHg and injection suxamethonium 75 mg intravenous (IV) was administered and high-frequency jet ventilation (HFJV) commenced by placing the O2 driven jet through open end of the rigid bronchoscope. Propofol and fentanyl infusions at 50 μg/kg/min IV and 1 μg/kg/h respectively were administered to deepen the anaesthetic depth and diminish the pressure response. FOB examination revealed a crescent shaped tracheal stenosis 5.5 cm away from the vocal cords, causing 75% luminal obstruction. The FOB was then removed and under fluoroscopy guidance, a Y silicon Dumon stent was deployed across the tracheal stricture using the special introducer. After removal of the introducer, the FOB was reintroduced and with the bronchoscopic forceps the stent was adjusted to fit in proper place. During this procedure anaesthesia was maintained with jet ventilation via the ventilating port as there was insufficient space at inlet of rigid bronchoscope for placing the jet needle []. Jet ventilation remained suspended for about 3 min during the stent insertion maneuver. After stent insertion anaesthesia was discontinued. The O2 saturation was maintained above 95% before, during and after the stent insertion. Following resumption of adequate spontaneous breathing, the rigid bronchoscope was removed.