Introduction
The management of the difficult airway is now quite rightly entrenched in anaesthetic practice, and relies on a pragmatic and to some degree evidence based approach which has been formulated into guidance that will apply to most situations.(1)
Quite rightly, the guidelines concentrate on what is thought to be best practice when faced with technical or anatomical difficulty. However, airway difficulty can be caused by the circumstances in which the patient is presented, in which case the situational awareness displayed by the anaesthetist is the key skill to successful management.
This article outlines the successful urgent management of three cases of difficult airway where the difficulty was presented by circumstance, rather than technical or anatomical issues.
Case 1
The anaesthetic team were called to the emergency department to assist with a patient who had taken an overdose of a variety of neuroactive substances. The referral was based on the fact that the patient was “uncooperative” and needed “airway protection.”
On arrival, the team were presented with a male in his 40’s escorted by two large security guards. No medical or nursing staff was present at that time. He was disorientated and aggressive to the point where he refused to be monitored, and had displaced cannulae. He was face down on the emergency department (ED) trolley, with arms and legs entwined in the cot sides. When approached, his arms would flail wildly, with purpose. He would not however open his eyes or interact appropriately. Glasgow Coma Scale (GCS) was recorded as 7/15 by emergency department staff. The Anaesthetic team judged the GCS to be greater, but it was immediately clear that the patient was in a state of drug induced inebriation to the extent that the airway was not suitably protected, and was in a condition that a medical ward would not be able to cope with as he was neither orientated nor alert. The patient briefly tolerated a short period of monitoring with a pulse oximeter, which showed normal saturations. No other intervention was possible as the patient would violently repel any other intervention due to their semi -conscious state. Admission to critical care following anaesthesia and IPPV was required for the patient’s own safety.
The team set up for a rapid sequence induction, but were unable to secure any iv access, to pre oxygenate the patient or position them appropriately without risk of harm to themselves or the patient. Obvious signs of a head injury were excluded, and it was decided that administration of a sedative was required to provide optimum conditions. The choice was between nasal midazolam, rectal lorazepam or intramuscular (im) ketamine or benzodiazepine. It was decided that the im route would be unreliable, and ketamine unpredictable following the presumed effects the substances ingested. Rectal lorazepam was impractical. Therefore 20mg nasal midazolam was administered with the team fully standing by to intervene as required. After five minutes, the patient was less aggressive, and the team safely turned him onto his back, and pre oxygenated him whilst administering cricoid pressure. IV access was immediately obtained as standard AAGBI monitoring was placed. A rapid sequence induction with propofol and suxamethonium was commenced. A grade I intubation resulted, and anaesthesia was maintained with propofol infusion and atracurium. A chest X ray confirmed that there was no evidence of aspiration. A CT scan confirmed that there was no evidence of head injury. The patient was taken to critical care, where they were successfully extubated the next morning.
Case 2
The anaesthetic team were placed on standby by the emergency department staff who were expecting an 11 year old child with learning problems, whom the paramedics stated had “unreadably low saturations” due to a likely pneumonia. On arrival, the child was extremely frightened and aggressive, despite being accompanied by parents and carers, to the point where it was impossible to attach any monitors or to administer oxygen. They would not accept being positioned on a trolley. The child was however deeply cyanosed, and it was clear that without immediate intervention a cardiac arrest would soon result.
All anaesthetic equipment and drugs had been prepared already. Fortuitously, two anaesthetic consultants were present, and decided that the only course of action was to ask the carers to restrain the child whilst iv access, and immediate rapid sequence induction took place. The parents and carers consented that this was the only way forward, and with the agreement of all staff, the child was gently restrained, whilst the anaesthetic team secured venous access and immediately administered propofol, suxamethonium and fentanyl. As soon as possib