Anaesthesia for tonsillectomy with or without adenoidectomy requires defence of the shared airway from blood and debris. This necessarily involves endotracheal intubation after induction, which may be gaseous or IV. If an uncuffed tube is used in the child patient, a suitable pack (ribbon gauze, for example) should be placed around the laryngeal additus to protect the larynx from contamination of blood and saliva. Use of a Boyle-Davis gag (Figure SI.3) will prevent compression of the tube during surgical positioning. Having decided upon intubation, IPPV should be used and commonly a non depolarising relaxant, opioid, vapour combination is used for the maintenance of anaesthesia. Extubation should be undertaken in the head down lateral position after adequate pharyngeal suction. There are two choices for timing of this event, while the patient is still deep or after protective reflexes have returned. The latter is more common today. Blood loss should be particularly carefully assessed in young children.
Post tonsillectomy haemorrhage is a specific problem that requires mention. Following post tonsillectomy haemorrhage, the patient will usually be pale, tachycardic and sweaty. Intravenous resuscitation is essential before induction and two different techniques of anaesthesia have been recommended. In both situations the patient should be placed head down, in left lateral position with suction to hand. Following preparation of all equipment a choice may be made between intravenous or gaseous induction. In the first instance after the usual RSI precautions (pre-oxygenation, cricoid pressure) a cautious dose of induction agent is given, followed by suxamethonium and securement of the airway by endotracheal intubation. Alternatively, a gaseous induction of halothane and oxygen may be employed using suction as necessary and enough time to achieve a plane of anaesthesia deep enough to permit laryngoscopy and intubation. Maintenance and extubation are as described above. Some authorities recommend the emptying of swallowed blood from the stomach with a nasogastric tube before extubation which would appear a wise counsel.
Figure SI.3 Boyle-Davis gag
Middle ear surgery has one main requirement which differentiates it from other surgical procedures. This is the need for control of blood loss to achieve the surgeon the best possible view down the microscope. In practice, "smooth' anaesthesia is desirable (for example no coughing or straining) and a relaxant, opioid, vapour technique is usually employed after intubation with an armoured endotracheal tube. Lidocaine spray to the larynx has been advocated before intubation to reduce the response to the presence of the tube as has the use of alfentanil with induction. Arterial hypotension is often requested, and provided there are no contra-indications this may be achieved by the use of sodium nitroprusside by controlled infusion or beta blockade (esmolol is a suitable choice). Inspired oxygen concentration should be increased and a slight head up tilt will reduce bleeding by aiding venous drainage. It has been suggested that avoidance of nitrous oxide is beneficial to avoid pressure rises in the middle ear as it diffuses in. Oxygen air mixtures are, therefore, recommended in this situation. An anti-emetic agent should be administered during the procedure as nausea from disturbance of labyrinthine function is frequent and post operative vomiting is particularly undesirable.
The majority of elective tracheostomies are performed on intensive care patients following long term oral intubation. In this instance anaesthesia is usually maintained by the use of opioid agents with or without volatile supplementation and muscle relaxants as required to facilitate IPPV. The critical feature of the procedure is to avoid withdrawing the existing endotracheal tube before the surgeon gaining control of the airway by securing the tracheostomy tube in the correct position. If this is not achievable, the original tube can be re-advanced and oxygenation maintained. If the endotracheal tube has been removed without securing the trachostomy tube correctly a potentially dangerous situation develops which may be fatal. Transfer of connecting tubing from old to new tube should be as quick as possible to avoid de-saturation. Emergency tracheostomy is a difficult and hazardous procedure best performed under local anaesthesia.
Was this article helpful?
This guide will help millions of people understand this condition so that they can take control of their lives and make informed decisions. The ebook covers information on a vast number of different types of neuropathy. In addition, it will be a useful resource for their families, caregivers, and health care providers.