Extubation in the Patient with a Compromised Airway

Dr Ali Diba, East Grinstead, UK

For the anaesthetist the smooth transition of the patient from the anaesthetised state with the inherent obtunding of respiratory and protective reflexes of the airways to the awake state with spontaneous respiration and airway protection has never been terribly easy. Patients undergoing surgery particularly involving sites comprising the anatomical airway at or above the glottis have posed particular problems which are compounded in the obese or in those with pre-morbid airway and ventilation compromise for other reasons.

There is little argument that under general anaesthesia, endotracheal intubation with a cuffed tracheal tube is the gold standard for control of the airway, its protection from the ingress of debris and the provision of relatively unimpeded surgical access. In the age of fiberoptics where the process of intubation even in previously impossible scenarios has been rendered relatively untaxing, perhaps the best demonstrator of our hitherto inability to solve the problems of extubation is the widespread use and advocation of the altogether inferior Laryngeal Mask Airway as the modish technique for the commonest of upper airway procedures such as tonsillectomy and dental extractions. 

Instrumentation of the airway to ensure patency during anaesthesia can itself necessitate a greater degree of anaesthesia in order to be tolerable. The still dominant anaesthetic drugs in use (volatile agents) have for so long been the basis of the provision of general anaesthesia that some of their particular adverse effects on the airway namely coughing, breath-holding and laryngospasm are often thought to be a feature of general anaesthesia rather than a peculiarity of these agents.

The books and anaesthetic journals tend only to tackle the subject of extubation from the viewpoint of the chemical control of the hypertensive response to arousal and extubation: little other useful practical guidance is on offer.

The presentation aims to show how extubation can be reproducibly made simple and anxiety free by exploiting the properties of modern intravenous anaesthetic drugs with short recovery profiles.

High levels of narcotisation obtund laryngeal reflexes and allow the awake patient to easily tolerate the tracheal tube and machine ventilation (and even laryngoscopy). Where this is combined with a clear-headed recovery from anaesthesia, the patient is able to obey commands to breath in spite of having little or no “intrinsic” respiratory drive. Remifentanil can be used to provide a narcotic based anaesthetic with intense narcotisation maintained until extubation. Thereafter the rapid elimination of the drug means that the patient only needs to be instructed to breath for a short period until resumption of spontaneous ventilation. The use of propofol for the hypnotic component of anaesthesia allows a lucid wake up with no additional respiratory irritation. The morbidly obese patient may be safely and easily extubated following tonsillectomy in the sitting position without difficulty in this manner.

For a more rapid recovery from surgical anaesthesia and in patients who cannot be relied upon to obey commands (e.g. small children) the two components can be stopped together whilst maintaining artificial ventilation until the tracheal tube is rejected at arousal. Extubation is still problem free although patients may cough once or twice at extubation. Breath holding and laryngospasm will not be seen.