A 54-year-old man, 160 cm tall and weighing 59 kg, with a past history of systemic amyloidosis and light chain multiple myeloma presented for emergency laparotomy with haematemesis and melaena. Upper gastrointestinal endoscopy under sedation with midazolam 7 mg had identified multiple erosions, but bleeding could not be controlled. Preoperative examination revealed a seriously ill patient, ASA IV, with continuing haematemesis. Conscious level was obtunded with a Glasgow Coma Scale of 9, and despite vigorous fluid resuscitation, there was continuing cardiovascular compromise with an arterial pressure of 85/55 mm Hg, and sinus tachycardia of 120 beats min1. Assessment of the airway was difficult in these circumstances but the patient was noted to have a short neck. Review of the patients notes revealed recent onset of dysarthria but no significant anaesthetic history.
Following application of routine monitoring, preoxygenation and the attachment of a Level 1 bloodwarmer, induction of anaesthesia was by a modified rapid sequence with etomidate 4 mg, fentanyl 100 µg and succinylcholine 100 mg. One-handed cricoid pressure was applied throughout by a trained anaesthetic nurse. Laryngoscopy with a Macintosh blade (size 3) revealed heavy soiling of the oropharynx with fresh blood, and a large tongue, which obstructed vision and contributed to a Grade 4 (Cormack and Lehane) view. A second attempt with a McCoy blade (size 3.5) failed to improve the view, and attempts to pass a gum elastic bougie blindly into the trachea were also unsuccessful. The airway was manipulated by jaw thrust and a size 4 Guedel airway was inserted. It then proved possible to ventilate the patient with a facemask and maintain oxygen saturation above 95%. Waking the patient was considered but thought to carry significant risk. As preparations were made to establish a surgical airway, it was decided to attempt intubation using the ILM (Intavent, UK). A second dose of succinylcholine 100 mg, preceded by glycopyrrolate 200 µg, was administered as the initial dose of muscle relaxant had worn off. A size 4 ILM was inserted with some difficulty and the cuff inflated with 30 ml of air. Ventilation via the ILM was initially partly obstructed, but changing the manner of application of cricoid pressure to a bimanual method with neck support resolved the problem. A size 7 armoured tracheal tube (Intavent) was then passed blindly through the mask into the trachea at the first attempt and the cuff inflated. Correct placement was confirmed by auscultation and E'CO2 monitoring.
Amyloidosis is not recognized as a common cause of difficult intubation despite often involving the aerodigestive tract. It is caused by deposition of amyloid protein extracellularly and affects many organs including the heart. Macroglossia, in which the tongue is hard and poorly mobile, is a recognized feature and contributed to the difficult intubation in this case.
The Australian Incident Monitoring Study3 emphasizes the importance of accurate preoperative airway assessment, but this was difficult in a non-compliant, obtunded and bleeding patient. Awake fibreoptic intubation would not have been an option due to considerable amounts of blood in the airway and continuing upper gastrointestinal bleeding. A size 4 ILM was chosen in preference to a size 5 because it was anticipated that macroglossia may make placement of the larger mask difficult or impossible. An interdental distance of 20 mm or less precludes use of the ILM,4 but reduced palatoglossal distance as a result of macroglossia has not been reported to cause problems.
In the face of continuing severe gastric bleeding, it was considered important to maintain cricoid pressure throughout. Cricoid pressure can impede the view at laryngoscopy and by obstructing the hypopharynx, prevent accurate placement of the ILM. A low success rate in placing the conventional laryngeal mask airway during cricoid pressure is well recognized,5 while single-handed cricoid pressure has been shown to significantly impair the ability to insert a tracheal tube and intubate through the ILM.6 Initial difficulties in ventilation with the laryngeal mask component in this patient were resolved when neck support was applied, thereby converting single-handed cricoid pressure to bimanual pressure.
This case demonstrates the successful use of the ILM during difficulty in intubation in a patient with amyloid macroglossia.
N. G. Smart
D. A. Varveris
P. Jacobs
Glasgow, UK
References
1 Brain A, Verghese C, Addey EV, Kapila A, Brimacombe J. The Intubating Laryngeal Mask II. A preliminary clinical report of a new means of intubating the trachea. Br J Anaesth 1997; 79: 7046
2 Baskett P, Parr M, Nolan J. The Intubating Laryngeal Mask. Results of a multicentre trial with experience of 500 cases. Anaesthesia 1998; 53: 11749[ISI][Medline]
3 Kluger MT, Tham EJ, Coleman N A, Runciman W B, Bullock M F. Inadequate preoperative evaluation and preparation: a review of 197 reports from the Australian Incident Monitoring Study. Anaesthesia 2000; 55: 11738[ISI][Medline]
4 Brimacombe JR. Difficult airway management with the Intubating Laryngeal Mask. Anesth Analg 1997; 85: 11735[ISI][Medline]
5 Asai T, Barclay K, Power I, Vaughan R. Cricoid pressure impedes placement of the laryngeal mask airway. Br J Anaesth 1995; 74: 5213
6 Harry RM, Nolan JP. The use of cricoid pressure with the intubating laryngeal mask. Anaesthesia 1999; 54: 6569[ISI][Medline]