Abstract
Although the term ‘tracheostomy’ simply means a hole entering the trachea, it can be usefully divided into tracheostomy (in which a hole is made between the anterior neck and the trachea, which remains otherwise intact) and laryngectomy (in which the larynx is removed and the trachea is joined to the neck as a blind-ending stoma). Both groups of patients have an increased risk of complications outside and within hospitals. Many of these are entirely avoidable by better knowledge and reliability of care. There is confusion about different types of tracheostomy and between management of complications of tracheostomy and laryngectomy stoma. There is a need for clear understanding of the differences and what represents good care of such patients and their airways. Complications include airway blockage and displacement. Harm may occur if airway emergencies are not managed promptly and in a structured manner. Standard operating procedures, algorithms and checklists have a role in improving reliability of care and approaches to emergencies. Recent evidence shows multidisciplinary teams using quality improvement principles can reduce complications, hasten decannulation and improve patient experience. The National Tracheostomy Safety Project and the Global Tracheostomy Collaborative have been established to improve education and safety of tracheostomy care.
History
A tracheostomy is an artificial opening made into the trachea through the anterior neck (Figure 29.1). This may be temporary or permanent. A tracheostomy tube is usually inserted, enabling gas to enter the trachea and lungs directly, bypassing the nose, pharynx and larynx.
Figure 29.1 (a and b) Tracheostomy tube in the anterior neck.
Tracheostomy is one of the earliest described surgical procedures, probably dating to the sixteenth century. Historically it was undertaken to relieve obstruction to the upper airway caused by trauma or tumour. In countries with advanced critical care services the majority of tracheostomies are now performed percutaneously by intensivists rather than by surgeons, with the commonest indication being to facilitate prolonged ventilation.
Indications
Indications for temporary and permanent tracheostomy are:
to secure and maintain a patent (clear) airway in actual or potential upper airway obstruction
to secure and maintain a safe airway in patients with injuries or surgery to the face, head or neck
to facilitate weaning from artificial ventilation
to facilitate long-term artificial ventilation
to facilitate tracheal suctioning where there is poor cough effort with sputum retention
to protect (partially) the airway of patients at high risk of aspiration
There is no convincing data that can guide clinicians as to the timing of tracheostomy. Prolonged use of a translaryngeal tracheal tube can damage the larynx and the upper airway and requires prolonged sedation. Balancing these risks against the risks of tracheostomy (procedural and post-placement) can be difficult.
Types of Tracheostomy
Tracheostomy may be temporary (short/long term) or permanent and may be formed electively or in an emergency. They may also be classified by their method of initial insertion.
Temporary tracheostomies are often used in patients with a temporary need for:
bypass of upper airway obstruction
‘tracheobronchial toilet’
‘protection’ against aspiration in patients with disordered pharyngolaryngeal neurological control mechanisms (e.g. head injuries or neurological diseases)
Certain maxillofacial or ENT surgical procedures require a temporary tracheostomy to facilitate the procedure.
It should be noted that while cuffs provide some protection against aspiration this is not complete, especially with low-pressure PVC cuffs, which have microfolds through which aspiration may occur. Silicone cuffs which have fewer folds may provide better protection.
Long-term/permanent tracheostomies are used when the underlying condition is chronic, permanent or progressive, including carcinoma of the naso-oropharynx or larynx, chronic respiratory support or long-term airway protection.
Surgical Tracheostomy
Surgical tracheostomies are usually undertaken in an operating theatre where conditions are sterile and lighting is good, although this is also possible in the emergency department or intensive care unit (ICU). General anaesthesia is commonly used, although tracheostomy under local anaesthesia is possible. Anaesthesia for tracheostomy requires careful consideration of airway management once sedative agents are administered.
In the anterior neck, midway between the cricoid cartilage and the sternal notch, a 2–3 cm long horizontal incision is made. The skin and platysma are dissected and the strap muscles retracted laterally, exposing the thyroid isthmus, which is either mobilised or divided. Following haemostasis, a cricoid hook or lateral stay sutures are used to expose the trachea and a small opening or ‘window’ is made in the trachea. A Björk flap may be created, where a part of the tracheal cartilage is incised, folded and sutured to maintain stoma patency. The tracheostomy tube is inserted through the stoma and may be sutured to the skin and/or secured with cloth ties or a holder.
Airway Management for Surgical Tracheostomy
Airway management for surgical tracheostomy will depend on the setting. In all settings communication between anaesthetic and surgical teams is paramount and national audits have shown that airway management may be difficult and associated with complications.
In an elective setting it is likely the trachea is already intubated. The tracheal tube will need to be withdrawn to enable passage of the tracheostomy tube. There is a risk of damaging the tracheal tube cuff during the surgery which may be overcome by inserting the tracheal tube deeply (cuff below surgery) or withdrawing it partially (cuff and distal tube above surgery). Both have limitations.
In the emergency setting and when the patient is not already intubated airway management may be much more complex. Where feasible, nasendoscopy before the procedure may assist in planning a safe approach. If general anaesthesia is safe tracheal intubation is usual, though a supraglottic airway (SGA) may occasionally be used and this may also be the case when a surgical airway is performed after an SGA is used for airway rescue and followed by surgical tracheostomy.
The most challenging situation is awake tracheostomy in the awake patient with airway obstruction. Efforts to assist oxygenation may require heliox or high flow nasal oxygenation. The optimal position required for surgery (fully supine and the neck fully extended) is often poorly tolerated and requires explanation: surgical compromise may be needed. Sedation may be unavoidable to ensure safety in the delirious patient but should be avoided wherever possible in a critical airway. Resisting sedation/anaesthesia and reassuring the patient may actually be the anaesthetist’s greatest challenge during high-risk awake tracheostomy.
Once the tracheostomy is inserted its position in the airway should be immediately confirmed with capnography. Airway suction to remove secretions, blood and debris is good practice. Endoscopy via the tracheostomy tube is useful to assess adequacy of tube placement. The distal lumen of the correctly positioned tube will be parallel to the tracheal wall – and at endoscopy the entire trachea will be visible (full moon view). If positioning is suboptimal endoscopy may only reveal a limited view of the trachea (half-moon or crescent moon) and this requires correction by repositioning or a different choice of tracheostomy tube.
Percutaneous Dilatational Tracheostomy
Percutaneous dilatational tracheostomy (PDT) has become the technique of choice in ICU as it is a relatively quick bedside procedure, can be performed by a non-surgeon and does not require transfer of the critically ill patient to theatre. It involves a modified Seldinger technique of four steps:
needle insertion into the trachea
guidewire insertion through the needle
conversion to a larger stoma through some form of dilation
insertion of the tracheostomy tube over the guidewire
Bleeding during the procedure is generally controlled by the tamponading effect of the tube in the dilated tract.
Several different dilatational techniques are described. Originally, serial dilatation using sequentially larger dilators was used, but single-step dilation with a curved tapering dilator is now the most commonly used technique (Ciaglia technique, Figure 29.2). In the Griggs technique forceps are introduced over a guidewire and then extended to dilate the stoma with the tracheostomy tube then placed between them. The Fantoni technique involves needle puncture of the trachea and passage of a retrograde guidewire through the vocal cords, followed by railroading a combined dilator and tracheostomy tube over the guidewire into the larynx and out through the anterior tracheal wall. The tracheostomy tube is then separated from the dilator and rotated 180° to face the carina. The PercuTwist technique involves rotating a screw-like dilator over a guidewire to dilate the stoma. Dilation using a high-pressure balloon has also been described.
A meta-analysis of studies comparing at least two PDT techniques included 1130 patients and reported broad equivalence between techniques and devices, except the Fantoni technique, which was associated with more significant complications. The single-step dilation technique was associated with fewer failures than Griggs, PercuTwist or balloon dilation techniques.
Indications and Contraindications for PDT
Indications for PDT are similar to those for surgical tracheostomy. Most are performed in ICU to facilitate weaning from mechanical ventilation, tracheal toilet or airway protection. It is an elective procedure and in emergency settings a surgical technique is generally preferred.
Contraindications include children, infection at the insertion site or an unstable cervical spine injury.
Distorted airway anatomy, previous tracheostomy, neck surgery or radiation, obesity (body mass index (BMI) > 30 kg m−2), bleeding diatheses, high positive end-expiratory pressure (PEEP) (≥ 10 cmH2O) or FiO2 (≥ 70%) and haemodynamic instability are relative contraindications to PDT. If a patient has notably abnormal clotting or a large vessel near the puncture site many will choose surgical tracheostomy and direct haemostasis; however, an experienced operator may still undertake PDT. The availability (and method of contact) of an airway surgeon should be established prior to commencing PDT.
Airway Management during PDT
Airway management during PDT requires an individual suitably experienced in airway management and anaesthesia. The patient should be anaesthetised and paralysed with the airway secured, as minor movements or coughing may lead to needle misplacement and injury. Perforation of the posterior tracheal wall is a particular risk.
The patients should be ventilated with an FiO2 of 100%. A tracheal tube must be withdrawn so that its tip does not lie in proximity to the tracheal puncture site and so that its cuff is not damaged by needle or guidewire insertion. Before manipulating the airway, position the patient with the neck extended, shoulders elevated and the bed at 30° head-up (to reduce venous pressure) for maximum exposure of the neck. Following oral and tracheal suction, the tracheal tube is withdrawn (or replaced) and the cuff positioned to just at/above the vocal cords. Conventional or videolaryngoscopy may be used, although the view may be worsened due to positioning.
Alternatively, an existing tracheal tube may be exchanged for an SGA prior to PDT. This requires an experienced skilled operator and optimal positioning of the SGA. A second generation SGA with a high airway seal and through which airway endoscopy is readily achieved should be chosen. Endoscopy facilitates full vision of the trachea to guide needle insertion. As with conventional anaesthesia, SGAs are not suitable for all, especially the obese and those with high airway pressures.
Whichever technique is chosen, oxygenation, ventilation and anaesthesia must be maintained throughout the procedure. Following airway device displacement, inability to perform PDT, or serious bleeding, the airway manager should be prepared to reintubate the patient. Only after confirming proper placement of the tracheostomy tube using capnography should the tracheal tube be removed.
Ultrasound Prior to Surgical Tracheostomy or PDT
Bedside ultrasound screening may enable optimal needle location by identifying the tracheal rings, thyroid isthmus and pretracheal vascular structures. It enables measuring the distance from the skin to the trachea and avoidance of overlying blood vessels and is especially useful in patients who are morbidly obese or have difficult neck anatomy in whom the trachea may be impalpable and may not be in the midline (See Chapter 7).
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