Tracheostomy
Scott E. Kopec
Timothy A. Emhoff
Although reports of performing tracheostomy date back to the first century BC [1], it was not performed regularly until the 1800s when used by Trousseau and Bretonneau in the management of diphtheria. In the early 1900s, this procedure was used to treat difficult cases of respiratory paralysis from poliomyelitis. Largely because of improvements in tubes and advances in clinical care, endotracheal intubation has become the treatment of choice for short-term airway management.
Although tracheostomy is occasionally required in critically ill and injured patients who cannot be intubated for various reasons (e.g., cervical spine injury, upper airway obstruction, laryngeal injury, and anatomic considerations), the most common use of this procedure today is to provide long-term access to the airway in patients who are dependent on mechanical ventilation. With improvements in critical care medicine over the past 30 years, more patients are surviving the initial episodes of acute respiratory failure, trauma, and extensive surgeries and are requiring prolonged periods of mechanical ventilation. It is now common practice to expeditiously convert these patients from translaryngeal intubation to tracheostomy. Tracheostomy is becoming a very common procedure in the intensive care unit (ICU). The prevalence of tracheostomies in ICU patients ranges from 8% to more than 30% [2,3].
In this chapter we review the indications, contraindications, complications, and techniques associated with tracheostomy. We also discuss the timing of converting an orally intubated patient to tracheostomy.
Indications
The indications for tracheostomy can be divided into three general categories: (i) to bypass obstruction of the upper airway, (ii) to provide an avenue for tracheal toilet and removal of retained secretions, and (iii) to provide a means for ventilatory support. These indications are summarized in Table 12.1 [4,5,6,7,8,9,10].
Anticipated prolonged ventilatory support, especially patients receiving mechanical ventilation via translaryngeal intubation, is the most common indication for placing a tracheostomy in the ICU. There are several advantages and disadvantages of both translaryngeal intubation and tracheostomy in patients requiring prolonged ventilator support,
and these are summarized in Table 12.2 [11,12,13]. Most authors feel that when the procedure is performed by a skilled surgical group, the potential benefits of tracheostomy over translaryngeal intubation for most patients justify the application despite its potential risks. However, there are no detailed clinical trials consistently confirming the advantages of tracheostomy in patients requiring prolonged mechanical ventilation. In a retrospective and a nonrandomized study, there were conflicting data regarding mortality in patients with respiratory failure of more than 1 week with regard to receiving a tracheostomy or continuing with an endotracheal tube [2,3].
and these are summarized in Table 12.2 [11,12,13]. Most authors feel that when the procedure is performed by a skilled surgical group, the potential benefits of tracheostomy over translaryngeal intubation for most patients justify the application despite its potential risks. However, there are no detailed clinical trials consistently confirming the advantages of tracheostomy in patients requiring prolonged mechanical ventilation. In a retrospective and a nonrandomized study, there were conflicting data regarding mortality in patients with respiratory failure of more than 1 week with regard to receiving a tracheostomy or continuing with an endotracheal tube [2,3].
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Contraindications
There are no absolute contraindications to tracheostomy. Relative complications include uncorrected coagulopathy, high levels of ventilator support (i.e., high levels of positive
end-expiratory pressure [PEEP]), and abnormal anatomy of the upper airway. However, a prospective cohort study has demonstrated that percutaneous tracheostomy can be safely preformed in patients with refractory coagulopathy from liver disease [14]. Morbidly obese patients with body mass index greater than 30 kg per m2 also appear to be at higher risk for complications with both open tracheostomy [15] and percutaneous tracheostomy [16]. In patients with severe brain injury, percutaneous tracheostomy can be safely performed without significantly further increasing intracranial pressure [17].
end-expiratory pressure [PEEP]), and abnormal anatomy of the upper airway. However, a prospective cohort study has demonstrated that percutaneous tracheostomy can be safely preformed in patients with refractory coagulopathy from liver disease [14]. Morbidly obese patients with body mass index greater than 30 kg per m2 also appear to be at higher risk for complications with both open tracheostomy [15] and percutaneous tracheostomy [16]. In patients with severe brain injury, percutaneous tracheostomy can be safely performed without significantly further increasing intracranial pressure [17].
Certain conditions warrant special attention before anesthesia and surgery. In patients undergoing conversion from translaryngeal intubation to a tracheostomy for prolonged ventilatory support, the procedure should be viewed as an elective or semielective procedure. Therefore, the patient should be as medically stable as possible, and all attempts should be made to correct the existing coagulopathies, including uremia. Ventilator settings should be reduced to where tube exchange during the tracheostomy is safe because during the exchange positive pressure is temporarily lost for some period of time. If not already on 5 cm H2O of PEEP, placing the patient supine and using 5 or 7.5 cm H2O of PEEP temporarily is a good test to decide if the patient will tolerate the exchange. For obvious reasons, emergent tracheostomies for upper airway obstruction may need to be preformed when the patient is unstable or has a coagulopathy.
Timing of Tracheostomy
When to perform a tracheostomy on an intubated, critically ill patient has continued to remain very controversial. Older recommendations range from performing a tracheostomy after just 3 days of translaryngeal intubation due to the risk of mucosal damage to the larynx and vocal cords [18] to more than 21 days on the basis of reported high complication rates of open tracheostomies [19]. In 2003, Heffner recommended a more up-to-date approach regarding the timing of converting an intubated patient to a tracheostomy [11]. This recommendation takes into account the very low mortality and morbidity associated with placing a tracheostomy, plus the advantages and disadvantages of both translaryngeal intubation and tracheostomy. In summary, if a patient remains ventilator dependent after a week of translaryngeal intubation, a tracheostomy can be considered. Whether to perform the procedure or not should depend on the anticipated duration of ventilatory support and the benefits of a tracheostomy in that specific patient. If the patient appears to have minimal barriers to weaning and appears likely to be successfully weaned and extubated within 7 days, tracheostomy should be avoided. In those patients whom it appears unlikely that they will successfully be weaned and extubated in 7 days, tracheostomy should be strongly considered. For those patients whose ability to wean and be extubated is unclear, the patient’s status should be readdressed daily [11].
Table 12.3 Studies Evaluating Early (≤7 Days) Versus Late (> 7 Days) Tracheostomy | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Over the past several years there has been momentum to perform a tracheostomy early, that is, after 1 week of mechanical ventilation. Fueling this was a meta-analysis [20], which suggested advantages to “early tracheostomy,” performed within 7 days of translaryngeal intubation over a “late tracheostomy” (> 7 days) in critically ill patients requiring mechanical ventilation. The meta-analysis combined five prospective studies and included 406 patients and suggested that early tracheostomy resulted in a decrease in length of ICU stay by an average of 15.3 days and a decrease in duration of mechanical ventilation by an average of 8.5 days [20]. Potential reasons for the decrease in duration of mechanical ventilation include easier weaning due to less dead space, less resistance, and less obstruction due to mucus plugging in patients with tracheostomies. There was no significant increase in hospital mortality or risk of hospital-acquired pneumonia. However, there are obvious limitations to the meta-analysis. Since this meta-analysis, several other studies have revealed conflicting data. Table 12.3 summarizes several studies comparing early versus late tracheostomy [20,21,22,23,24,25,26,27,28]. In summary, it remains unclear if early tracheostomy has any impact on mortality, length of ICU stay, days on mechanical ventilation, or ventilatory-associated pneumonia. Until more definitive data are available, Heffner’s 2003 recommendations [11] appear to make the most sense for most medical and surgical patients on prolonged mechanical ventilation.
Early tracheostomy may be beneficial in some specific instances. Patients with blunt, multiple-organ trauma have a shorter duration of mechanical ventilation, fewer episodes of nosocomial pneumonia [29], and a significant reduction in hospital costs [30] when the tracheostomy is performed within 1 week of their injuries. Similar benefits have been reported in patients with head trauma and poor Glasgow Coma Score [31,32,33], acute spine trauma [34,35], and thermal injury [36] if a tracheostomy is performed within a week after the injury. Also, patients with facial injuries may require early tracheostomy to allow or facilitate facial fracture surgery, fixation, and immobilization.
Procedures
Emergency Tracheostomy
Emergency tracheostomy is a moderately difficult procedure requiring training and skill, experience, adequate assistance, time, lighting, and proper equipment and instrumentation. When time is short, the patient is uncooperative, anatomy is distorted, and the aforementioned requirements are not met, tracheostomy can be very hazardous. Emergency tracheostomy comprises significant risks to nearby neurovascular structures, particularly in small children in whom the trachea is small and not well defined. The risk of complications from emergency tracheostomy is two to five times higher than for elective tracheostomy [37,38]. Nonetheless, there are occasional indications for emergency tracheostomy [39], including transected trachea, anterior neck trauma with crushed larynx [40], severe facial trauma, acute laryngeal obstruction or near-impending obstruction, and pediatric (younger than 12 years) patients requiring an emergency surgical airway in whom an cricothyrotomy is generally not advised. In emergency situations when there is inadequate time or personnel to perform an emergency tracheostomy, a cricothyrotomy may be a more efficient and expedient manner to provide an airway.
Cricothyrotomy
Cricothyrotomy (cricothyroidotomy) was condemned in Jackson’s [41] 1921 article on high tracheostomies because of excessive complications, particularly subglottic stenoses [42]. He emphasized the importance of the cricoid cartilage as an encircling support for the larynx and trachea. However, a favorable report of 655 cricothyrotomies, with complication rates of only 6.1% and no cases of subglottic stenoses [43], prompted reevaluation of cricothyrotomy for elective and emergency airway access. Further reports emphasized the advantages of cricothyrotomy over tracheostomy. These include technical simplicity, speed of performance, low complication rate [43,44,45,46,47], suitability as a bedside procedure, usefulness for isolation of the airway for median sternotomy [46,48], radical neck dissection [49], lack of need to hyperextend the neck, and formation of a smaller scar. Also, because cricothyrotomy results in less encroachment on the mediastinum, there is less chance of esophageal injury and virtually no chance of pneumothorax or tracheal arterial fistula [47]. Despite these considerations, many authorities currently recommend that cricothyrotomy should be used as an elective long-term method of airway access only in highly selective patients [41,43,49,50,51]. Use of cricothyrotomy in the emergency setting, particularly for managing trauma, is not controversial [52,53,54]. Emergency cricothyrotomy is useful because it requires a small number of instruments and less training than tracheostomy and can be performed quickly as indicated as a means of controlling the airway in an emergency when oral or nasotracheal intubation is nonsuccessful or contraindicated. The cricothyroid membrane is higher in the neck than the tracheal rings and therefore closer to the surface and more accessible. In emergency situations, translaryngeal intubations fail because of massive oral or nasal hemorrhage or regurgitation, structural deformities of the upper airway, muscle spasm and clenched teeth, and obstruction by foreign body through the upper airway [52]. Cricothyrotomy finds its greatest use in trauma management, axial or suspected cervical spine injury, alone or in combination with severe facial trauma, where nasotracheal and orotracheal intubation is both difficult and hazardous. Thus cricothyrotomy has an important role in emergency airway management [53].
Use and Contraindications
Cricothyrotomy should not be used to manage airway obstruction that occurred immediately after endotracheal extubation because the obstruction may be found below the larynx [41,43,53]; likewise, with primary laryngeal trauma or diseases such as tumor or an infection, cricothyrotomy may prove to be useless. It is contraindicated in infants and children younger than 10 to 12 years under all circumstances because stenosis and even transection are possible [53]. In this age group, percutaneous transtracheal ventilation may be a temporizing procedure until the tracheostomy can be performed.
Anatomy
The cricothyroid space is no larger than 7 to 9 mm in its vertical dimension, smaller than the outside diameter of most tracheostomy tubes (outside diameter 10 mm). The cricothyroid artery runs across the midline in the upper portion, and the membrane is vertically in the midline. The anterior superior edge of the thyroid cartilage is the laryngeal prominence. The cricothyroid membrane is approximately 2 to 3 cm below the laryngeal prominence and can be identified as an indentation immediately below the thyroid cartilage. The lower border of the cricothyroid membrane is the cricoid cartilage [47,48,52,55]. A description of the cricothyrotomy procedure is contained in standard surgical texts.
Complications
The report of incidents of short- and long-term complications of cricothyrotomy ranges from 6.1% [43] for procedures performed in elective, well-controlled, carefully selected cases to greater than 50% [53,56] for procedures performed under emergency or other suboptimal conditions. The incidence of subglottic stenosis after cricothyrotomy is 2% to 3% [42,44]. This major complication occurs at the tracheostomy or cricothyrotomy site, but not at the cuff site [57]. Necrosis of cartilage due to iatrogenic injury to the cricoid cartilage or pressure from the tube on the cartilage may play a role [54]. Possible reasons that subglottic stenoses may occur more commonly with cricothyrotomy than with tracheostomy are as follows: the larynx is the narrowest part of the laryngotracheal airway; subglottic tissues, especially in children, are intolerant of contact; and division of the cricothyroid membrane and cricoid cartilage destroy the only complete rings supporting the airway [42]. Furthermore, the range of tube sizes is limited due to the rigidity of the surrounding structures (cricoid and thyroid cartilage), and the curvature of the tracheostomy tube at this level may obstruct the airway due to potential posterior membrane impingement [58]. Prior laryngotracheal injury, as with prolonged translaryngeal intubation, is a major risk factor for the development of subglottic stenosis after cricothyrotomy [42,44].
The association of cricothyrotomy with these possible complications leads most authorities to consider replacing a
cricothyrotomy within 48 to 72 hours with a standardized tracheostomy procedure. This is commonly done by an open surgical tracheostomy (OST), which occurs between the second and third tracheal rings, as compared to a percutaneous dilational tracheostomy (PDT), which usually occurs between the cricoid cartilage and the first ring or the first and second rings [58].
cricothyrotomy within 48 to 72 hours with a standardized tracheostomy procedure. This is commonly done by an open surgical tracheostomy (OST), which occurs between the second and third tracheal rings, as compared to a percutaneous dilational tracheostomy (PDT), which usually occurs between the cricoid cartilage and the first ring or the first and second rings [58].
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