**6.3 Wide-bore cannula**

Wide-bore cannula over the guidewire: some wide-bore cannula kits, such as the Cook Melker® emergency cricothyrotomy set, use a wire-guided (Seldinger) technique. This approach is less invasive than a surgical cricothyroidotomy and decrease the need for special machine for ventilation. The skills required are familiar to anaesthesiologists and intensivists because they are common to central line insertion and per-cutaneous tracheostomy method; however, these techniques require fine and smooth motor control, making them less suited to stressful situations. However, a wire-guided technique may be a reasonable alternative for anaesthetists who are experienced with this method, the evidence suggests that a surgical cricothyroidotomy is both faster and more reliable.

Non-Seldinger wide-bore cannula: A number of non-Seldinger wide-bore cannula-over-trochar devices are available for airway rescue. Although successful use has been reported in Cannot intubate, cannot oxygenate (CICO), there have been no large studies of these devices in clinical practice [43].

#### **7. Postoperative management**

#### **7.1 Extubation**

Extubating patients at the end of surgery should be discussed between anaesthesia and surgery teams. Patients with severe trauma to the airway, those with

pan facial fracture fixation, prolonged surgery and airway oedema should be kept ventilated in intensive care unit. Extubating patients should be done carefully with all equipment for reintubation ready. Some patients may be extubated in operating theater over airway exchange catheters (AEC) (**Figure 8**).

AEC is a long hollow bougie that comes in several sizes and can be placed into the trachea through the tracheal tube. The tracheal tube is then removed, and the AEC left in the airway with the tip at the level of the mid trachea. It is important that the catheter remains above the carina, and it should not be inserted beyond 25 cm in an adult patient. The AEC can then be used in the same way as a bougie to help reintubate the trachea in case of deterioration. It has been used in the recovery unit and on critical care unit after head and neck surgery. Usually, the AEC can be left in for few hours after extubation but is can be tolerated for up to 72 h [44].

While transferring the patient to intensive therapy unit (ITU), it is safer to keep the patient asleep with tracheal tube in place, but extra care to be taken to avoid tube dislodgment.
