Tracheotomy

The technique of creating a hole (the tracheostomy) in the trachea.

Indications

To provide an artifi cial airway in place of orotracheal or nasotracheal intubation. This may be to provide better patient comfort, avoid vocal cord, mouth or nasal trauma or, in an emergency, bypass acute upper airway obstruction. The optimal time to perform a tracheotomy in an intubated patient is not known; a prospective randomised study (the ‘TracMan’ trial) is underway in the UK. Reduced need for sedation, the potential to eat, drink and speak, and facilitation of mouth care are all advantages.

Percutaneous tracheotomy

Percutaneous tracheotomy can be performed in the ICU. Coagulopathy should be excluded or treated first. Subcutaneous tissues are infi ltrated with 1% lidocaine and epinephrine (adrenaline). After a 1–1.5cm midline skin crease incision, the subcutaneous tissue is blunt-dissected to the anterior tracheal wall. The ET tube tip is withdrawn to the level of the vocal cords. The trachea is then punctured in the midline with a 14G needle between the 1st and 2^nd tracheal cartilages (or lower), allowing guide wire insertion. The stoma is created by dilatation to 32–36Fr (Ciaglia technique) or by a guided forceps dilating tool (Schachner–Ovill technique). In the former case, the tracheostomy tube is introduced over an appropriate-sized dilator, and in the latter, through the open dilating tool. End-tidal CO2 monitoring confirms adequate ventilation during the procedure. Fibreoptic bronchoscopy may be used to confirm correct tracheal placement and no trauma to the posterior tracheal wall.

Complications

The main early complication is haemorrhage from vessels anterior to the trachea. This is usually controlled with direct pressure or, occasionally, sutures. Bleeding into the trachea may result in clot obstruction of the airway; endotracheal suction is usually effective. Paratracheal placement should be rare, but promptly recognised by the inability to ventilate the lungs. Later complications include tracheostomy tube displacement, stomal infection, and tracheal stenosis. Stenosis is often related to lowgrade infection and is claimed to be more common with open tracheotomy. Rare complications include tracheo-oesophageal fi stula due to trauma or pressure necrosis of the posterior tracheal wall, or erosion through the lateral tracheal wall into a blood vessel.

Maintenance of a tracheostomy

Since the upper air passages have been bypassed, artificial humidification is required. Cough is less effective without a functioning larynx so regular tracheal suction will be necessary. Natural laryngeal PEEP is lost with a tracheostomy. The risk of basal atelectasis can be overcome with CPAP or attention to respiratory exercises that promote deep breathing. After 3–5d, the tracheostomy tube can be safely replaced.

Tracheostomy tube removal

Before removing the tube, ensure the upper airway is patent, either by allowing the patient to exhale passed an occluded tube or by visualisation.

Tracheotomy tubes

Standard high volume, low pressure cuff

Fenestrated, with or without cuff

Useful where airway protection is not a primary concern. May be closed during normal breathing while providing intermittent suction access.

Fenestrated, with inner tube

As above, but with an inner tube to facilitate closure of the fenestration during intermittent mechanical ventilation.

Fenestrated, with speaking valve

Inspiration allowed through the tracheostomy to reduce dead space and inspiratory resistance. Expiration through the larynx via the fenestration, allowing speech and the advantages of laryngeal PEEP.

Adjustable flange

Accommodates extreme variations in skin to trachea depth while ensuring the cuff remains central in the trachea.

Pitt speaking tube

A non-fenestrated, cuffed tube for continuous mechanical ventilation and airway protection with a port to direct airflow above the cuff to the larynx. When airflow is directed through the larynx, some patients are able to vocalise.

Passy–Muir speaking valve

This expiratory occlusive valve is placed onto the tracheostomy tube to permit inspiration through the tracheostomy and expiration through the glottis. The tracheostomy tube cuff must be first deflated. The valve allows phonation, facilitates swallowing, and may reduce aspiration. Small studies have suggested that it may reduce the work of breathing. The potential tidal volume drop through cuff deflation makes this valve only suitable in those patients requiring no (or relatively low level) invasive ventilator support.

Silver tube

An uncuffed tube used occasionally in ENT practice to maintain a tracheostomy fistula.