Surgical tracheostomy, as described by Chevalier Jackson,¹⁰ is a surgical procedure that provides an airway through the cervical trachea. It remains the standard against which all other procedures with the same aim must be compared in terms of success and complications rates. Classically, the procedure is performed in the operating room under general or local anesthesia, as dictated by the clinical situation. An open tracheostomy may be performed at the bedside in the ICU or in the emergency room in urgent situations. After an initial skin incision, sharp dissection is carried out to the thyroid isthmus, which is divided. The cervical trachea is then incised and a tracheostomy tube inserted.

2 Percutaneous Tracheostomy

Percutaneous tracheostomy is performed by means of a skin puncture into the trachea that is subsequently dilated to form a stoma, rather than creating a stoma by surgical incision.¹¹ Although there are many techniques for performing a percutaneous tracheostomy, the initial part of the procedure always involves a puncture through the skin into the trachea, which is then enlarged by dilation or with forceps to spread the puncture to a size that allows placement of an appropriate tracheostomy tube. These techniques are typically used in patients with an established airway (i.e., endotracheal tube [ETT] or laryngeal mask airway [LMA]) and are mostly used for intubated ICU patients.

Emergency situations were traditionally considered absolute contraindications to the use of this technique, but in the past few years, some reports have supported its safety and feasibility in selected emergent cases.^12,¹³ The Ciaglia technique, first described in 1985, is the original technique now described as percutaneous dilational tracheostomy (PDT). It involves making a very small skin incision, introducing a needle into the trachea, and dilating the opening with sequentially larger dilators to allow insertion of a tracheostomy tube of the selected size. As originally described, this procedure was performed blind, but it is increasingly performed under continuous endoscopic guidance.

Other modifications of the Ciaglia technique include the use of lower tracheal rings interspaces (originally performed in the interspace between the cricoid cartilage and the first tracheal ring) and the use of a single, curved dilator to replace the original multiple dilators. Of the percutaneous approaches described, the Ciaglia technique with continuous endoscopic visualization and use of a single dilator is considered by many to be the safest, and it is the most widely used in North America.

The Griggs guidewire dilating forceps technique involves placing a guidewire through an initial puncture site. The area is forcibly enlarged with the use of a dilating forceps (i.e., grooved Howard-Kelly forceps) to obtain a stoma of the desired size. One advantage of this technique is the reduced amount of compression on the airway by the forceps compared with other dilational methods. The procedure as originally described is performed blind and subject to complications such as false passage and subcutaneous emphysema. Concurrent endoscopic visualization reduces these risks, although bleeding may be a problem because of tearing of adjacent structures when inserting and opening the forceps.

The Fantoni technique is based on retrograde dilation of an initial tracheal puncture. During this procedure, a needle is inserted between the tracheal rings (i.e., first and second or second and third) and directed cranially. A guidewire is then passed through the needle and directed toward the oral cavity. Dilation is carried out by means of a conic cannula inserted over the guidewire through the oral cavity. Ventilation at this stage is maintained by means of a special, small ETT that allows passage of the conic cannula alongside the ETT. The tracheostomy tube is ultimately brought out in a retrograde fashion through the cervical trachea and skin. This technique is used primarily in Italy, where it originated, but it has found little applicability in North America, because it is lengthy to perform and involves potential loss of the airway due to the many airway manipulations necessary to perform the procedure and secure the cannula in its final position.

3 Percutaneous Dilational Cricothyrotomy and Tracheostomy in Airway Control

a the Problem of Airway Control

Adverse outcomes related to respiratory events account for one of the two largest classes of injury in the American Society of Anesthesiologists (ASA) Closed Claims Project. As reported by Caplan and colleagues and Cheney and associates, the two major categories of anesthesia-related events or mechanisms causing death or brain damage between 1975 and 2000 were respiratory and cardiovascular difficulties, which together made up 68% of damaging events.^14,¹⁵ Three mechanisms of injury were responsible for most of the adverse respiratory events: difficult ETT placement (23%), inadequate ventilation (22%), and esophageal intubation (13%).

In an analysis of claims against the National Health System in England between 1995 and 2007,¹⁶ airway and respiratory claims accounted for 12% of anesthesia-related claims, 53% of deaths, 27% of cost, and 10 of the 50 most expensive claims in the dataset. These claims most frequently described events at induction of anesthesia, involved airway management with a tracheal tube, and typically led to hypoxia and the patient’s death or brain injury.

In the operating room, in the ICU (or in other hospital areas), and in the prehospital setting, three difficult scenarios have been repeatedly observed during attempts to control the airway: (1) the airway can be easily controlled by mask ventilation, but endotracheal intubation is not possible; (2) the airway cannot be mask ventilated but can be intubated; and (3) rarely, the airway cannot be mask ventilated or intubated. It is every anesthesiologist’s nightmare to encounter a true difficult airway as depicted in the third scenario.¹⁷ Five to 35 of 10,000 patients (0.05% to 0.35%) reportedly cannot be endotracheally intubated, and approximately 0.01 to 2.0 of 10,000 patients are difficult to mask ventilate and intubate.^18,¹⁹

ASA guidelines provide a difficult airway algorithm and suggest strategies for evaluating, preparing for, and intubating the difficult airway. They also consider the relative merits and feasibility of alternative management choices, such as nonsurgical versus surgical techniques for the initial approach to ventilation, awake intubation versus intubation after induction of general anesthesia, and preservation versus ablation of spontaneous ventilation. The algorithm describes emergency and nonemergency pathways for managing the airway if intubation fails. The ASA guidelines also suggest that equipment suitable for “emergency surgical airway access” be among the contents of a portable storage unit readily available in the operating room. The algorithm suggests that emergency invasive airway procedures are “surgical or percutaneous tracheostomy or cricothyrotomy.”

ASA guidelines offer a stepwise approach to the patient with a difficult airway, primarily focusing on difficulties encountered in the operating room, and offer strategies to anticipate and treat a difficult airway in this environment. However, the anesthesiologist is often called on to manage the airways of critically ill patients in other hospital environments, such as the emergency department, wards, diagnostic areas (e.g., radiology), or ICUs. In all settings, it is important that anesthesiologists are trained and prepared to recognize and manage situations in which cricothyrotomy or percutaneous tracheostomy, or both, are considered as preferred options.

b Roles of the Anesthesiologist, Otolaryngologist, and Emergency Medicine Physician

The anesthesiologist may be called immediately or after other physicians have attempted unsuccessfully to secure the airway or failed to recognize the futility of standard intubation techniques. In rare instances, the availability of a physician skilled in the technique of cricothyrotomy or percutaneous tracheostomy may be life-saving. This individual should be the anesthesiologist. Appropriate equipment for cricothyrotomy should be available throughout the hospital or as part of an emergency airway kit. No data exist regarding how frequently anesthesiologists are called to secure an airway outside the operating room, but in many hospitals, this responsibility seems to be handled more frequently by other physicians.²⁰^–²³

Each institution should have a clear plan for alerting qualified individuals when emergency airway support is required in different areas of the hospital.²⁴ Many publications describe the use of various types of advanced airway equipment, report the availability of such devices, and explain the use of simulators to teach difficult airway management skills, and many articles identify the need to educate residents in advanced airway techniques.

Organizing resources and staff to manage a difficult airway and maintaining appropriate training are important for patient safety and clinical quality.^25,²⁶ In 2000, Showan and Sestito proposed that the components of a successful airway management system include personnel, training, an emergency response system, an oversight process, standardized equipment, and patient education. As with any type of emergency, preparedness is the key when planning for response.²⁷^–³⁰

In 1996, a comprehensive airway program was introduced at Johns Hopkins.²⁶ The core components of the comprehensive difficult airway program were communication and electronic medical record information (including airway documentation), equipment, personnel, and education. Investigators based their implementation on the causes that required a surgical airway and the inability of an anesthesiologist to intubate and ventilate. The causes were an inability to access the written medical record, resulting in a lack of preoperative information about the patient’s airway; lack of immediate access to equipment and supplies necessary to manage a difficult airway; and lack of availability of trained personnel to help manage and secure the airway.

Continuing medical education is essential to maintain skills in performing emergent cricothyrotomy, and standardized simulation alone may not be sufficient to warrant optimal training. Individual skills, availability of devices, and training in specific techniques may deviate from standard guidelines, making “at site, ad hoc” guidelines necessary.

A threatened airway protocol has been proposed for implementing an escalation-based model at The University of Texas Medical School at Houston.³¹ The model is based on seven general principles to guide physicians in the identification and management of situations in which hospitalized patients may have rapid deterioration of a condition affecting the upper airway that requires immediate intervention to maintain or reestablish ventilation and oxygenation. These seven principles are concerned with appropriate communication among providers, maintenance of oxygenation, avoidance of sedation until the patient is in a safe environment, complete airway assessment, maintenance of spontaneous ventilation as long as possible, and avoidance of rapid-sequence induction (i.e., administration of a muscle relaxant without a prior attempt to ventilate), unless an easy airway and a full stomach are expected. Four main features constitute the cornerstones of management of a patient with a threatened airway: identification of the airway emergency and escalation of the approach to management, choice of appropriate sedation or anesthesia technique, positioning, and articulation of plans for intervention. A progressive algorithm (Fig. 30-4) that guides the progression of the necessary steps has been inspired by others’ work.^31,³² The use of specific airway devices or tools is mandated in the primary and secondary plans by the success in securing the airway or depending on changes in airway viability (Fig. 30-5).

Figure 30-4 Progressive escalation sequence for a threatened airway.

Figure 30-5 Airway approach algorithm for a threatened airway.

The otolaryngologist plays a critical role in airway management by contributing a skill set that is different from but complementary to that of the anesthesiologist. Circumstances may range from well-controlled elective situations to near-panic, last-ditch attempts to establish an airway when all else has failed.³³ The otolaryngologist possesses an excellent knowledge of the three-dimensional anatomy of the upper aerodigestive tract and the variations encountered in pathologic circumstances. This knowledge and expert endoscopy skills can assist the anesthesiologist in determining a difficult airway.

II Historical Perspective

Surgical manipulation of the trachea for emergent airway control is one of the oldest invasive procedures documented. It was performed in ancient Egypt and India more than 3000 years ago. Tracheostomy was mentioned in the writings and illustrations of the great Greek physician Galen (130 to 200 AD). He provided anatomic drawings of the airway and favored a vertical rather than horizontal incision in emergencies. He based his anatomic knowledge on dissections of animals and assumed that the structures were identical in the human body. Galen also stated that Asclepiades (124 to 56 BC), who practiced in Rome, recommended opening the trachea in its upper part to prevent suffocation. Antyllus (approximately 150 AD) described the indications for and technique of tracheostomy, advocating a transverse incision between two rings. Galenic teaching persisted for more than 1300 years, until Andreas Wesele Vesalius (1515 to 1564 AD) published De Humani Corporis Fabrica, detailing the first correct description of human anatomy. Vesalius secretly conducted extensive dissection of human cadavers and, at age 28, published his landmark work in seven volumes. Included was a detailed description of tracheostomy—control of the airway with the use of a cane or reed and assisted ventilation of the lung. He allegedly performed a tracheostomy and experimentally inflated the lungs of a dead Spanish nobleman, whose heart was reported to beat again. His action outraged the medical and clerical communities.

During the next 300 years, very few reports were published regarding the surgical control of the airway, and they were primarily limited to experimental control of breathing in laboratory animals. In Respiratory Changes of Intrathoracic Pressure, published in 1892, Samuel Meltzer described insertion of breathing tubes through a tracheostomy and successfully controlling ventilation in curarized animals. In France, Armand Trousseau recognized the importance of emergency tracheostomy in airways compromised by upper airway obstruction, diphtheria, and massive infection in the oropharynx and neck.

In 1909, Chevalier Jackson,¹⁰ a laryngologist at the Jefferson Medical School in Philadelphia, described the technical details of surgical tracheostomy and standardized the procedure. Jackson’s technique was for years considered the preferred method of surgical airway management. Jackson later published the results of 30 years’ observation of his own tracheotomized patients and reported a very high incidence of laryngeal and subglottic stenosis in patients who underwent a procedure that he referred to as high tracheostomy, involving division of the cricoid or thyroid cartilage.³⁴ As a consequence, the high tracheostomy technique was abandoned for many decades.

In 1969, Toye and Weinstein described a technique for percutaneous tracheostomy based on the premise that a functional tracheal airway could be more rapidly and safely achieved percutaneously than with Jackson’s method of surgical dissection.³⁵ The technique involved inserting a needle into the trachea and dilating the resultant needle tract to allow placement of a breathing catheter.

Cricothyrotomy, which differed from high tracheostomy because it involved opening of the CTM instead of dissection of the cricoid cartilage, was proposed again in 1976 by two Denver cardiothoracic surgeons, Brantigan and Grow. They published the results of 655 consecutive cricothyrotomies in which there were minimal complications and no reported incidence of subglottic stenosis. Subsequently, other clinical and experimental series have been reported, and cricothyrotomy has become generally accepted. The procedure was found to be faster, simpler, less invasive, and less likely to cause bleeding than tracheostomy. It is associated with lower morbidity and mortality rates than emergency tracheostomy, making it desirable as an emergency technique for gaining immediate airway control. Various modifications of the original technique have been developed. The use of the Seldinger technique for insertion, as described by Corke and Cranswick in 1988, enhances the safety of the procedure.⁸

Using a guidewire and passing a dilator to create a channel reduce the chance of incorrect placement and damage to surrounding blood vessels. Interest in cricothyrotomy as an alternative to endotracheal intubation is largely the result of the development of emergency medicine as a distinct specialty and the frequent treatment of patients with difficult airways in the prehospital and emergency department environments. Emergency physicians and prehospital providers often encounter patients with life-threatening injuries who cannot be intubated by conventional routes and who need immediate and definitive treatment. Most reports of the use of cricothyrotomy in emergent situations appear in the emergency medicine literature. For anesthesiologists, interest in PDT and PDC increased as part of a trend toward less invasive surgical procedures.

The Ciaglia technique, first described in 1985, is the original technique now described as PDT. In this technique, insertion of the guidewire is followed by serial dilations performed with multiple, progressively larger dilators.³⁶ The Rapitrach method, proposed in 1989 by Schachner and coworkers, entails the use of dilating forceps and a single-step dilating technique.³⁷

In 1990, Griggs and colleagues presented the guidewire dilating forceps method, which was similar to the Rapitrach method and based on a one-step dilating techinque ³⁸ that used a modified forceps. In 1997, Fantoni proposed the translaryngeal tracheostomy technique based on retrograde dilation of an initial tracheal puncture by means of a conic cannula inserted through the oral cavity.³⁹

The Ciaglia Blue Rhino, a modified version of the Ciaglia technique, was introduced by Cook Medical (Bloomington, IN) in 2000.⁴⁰ In this technique, the series of sequentially larger dilators of the original Ciaglia technique is replaced by a single, curved dilator with a hydrophilic coating, the Blue Rhino, that progressively dilates the stoma in one step.

In 2002, Frova and Quintel described the Percutwist tracheostomy technique. A “rotating dilation” is performed in a single step by means of a screwlike, rotating device.⁴¹ In 2008, a further development of the Ciaglia technique was presented by Cook Medical: the Ciaglia Blue Dolphin balloon percutaneous tracheostomy introducer. This device combines balloon dilation and tracheal tube insertion into one step.

Many of the techniques proposed for PDC and PDT are performed over guidewires. Although anesthesiologists are familiar with the Seldinger technique for the insertion of vascular catheters, many are unacquainted with airway management techniques that use airway devices based on the same technology and concept.^27,⁴²

III Anatomy and Physiology

Safe and rapid performance of cricothyrotomy requires a thorough knowledge of cricothyroid space anatomy (Fig. 30-6) and its relation to other structures in the neck.^1,^6,⁴³^–⁴⁷ The CTM ligament is 10 mm long and 22 mm wide and is composed mostly of yellow elastic tissue. It covers the cricothyroid space and is located in the anterior neck between the thyroid cartilage superiorly and the cricoid cartilage inferiorly. The cricothyroid space can be readily identified by palpating a slight dip or indentation in the skin immediately below the laryngeal prominence.

Figure 30-6 A, Dissection anatomy. B, External landmarks.

(A, From De Leyn P, Bedert L, Delcroix M: Tracheotomy: Clinical review and guidelines. Eur J Cardiothorac Surg 32:412–421, 2007.)

The CTM consists of a central anterior triangular portion (i.e., conus elasticus) and two lateral parts. The thicker and stronger conus elasticus narrows above and broadens below, connecting the thyroid to the cricoid cartilage. It lies subcutaneously in the midline and is often crossed horizontally in its upper third by the superior cricothyroid vessels. To minimize the possibility of bleeding, the CTM should be incised at its inferior-third portion. The two lateral parts are thinner, lie close to the laryngeal mucosa, and extend from the superior border of the cricoid cartilage to the inferior margin of the true vocal cords. On either side, the CTM is bordered by the cricothyroid muscle. Lateral to the membrane are venous tributaries from the inferior thyroid and anterior jugular veins. Because the vocal cords usually lie 1 cm above the cricothyroid space, they are not commonly injured, even during emergency cricothyrotomy.⁴⁸ The anterior jugular veins run vertically in the lateral aspect of the neck and are rarely injured, but tributaries may occasionally course over the cricothyroid space and be damaged during the procedure. Characteristically, the CTM does not calcify with age and lies immediately underneath the skin.

Variations in the anatomy and dimensions of the CTM are common. The anterior cricothyroid space is trapezoidal and has a cross-sectional area of approximately 2.9 cm². The mean distance between the anterior borders of the inferior thyroid cartilage and the superior cricoid cartilage is 9 mm (range, 5 to 12 mm), whereas the width of the anterior cricothyroid space ranges from 27 to 32 mm. The cricothyroid space is not much larger than 7 mm in its vertical dimension, and that space may be narrowed further by contraction of the cricothyroid muscle. The vertical distance between the undersurface of the true vocal cords and the lower anterior edge of the thyroid cartilage is between 5 and 11 mm. The vertical height of the CTM from the superior border of the cricoid cartilage to the inferior border of the thyroid cartilage in the midline varies from 8 to 19 mm (mean, 13.69 mm), a somewhat greater distance that can probably be explained by the fresh rather than fixed state of specimens.

The arterial and venous vessel patterns in the neck area surrounding the CTM vary considerably. Although the arteries always lie deep to the pretracheal fascia and are easily avoided during a skin incision, veins may be found in the pretracheal fascia and between the pretracheal and superficial cervical fascia. Vascular structures may cross vertically and anterior to the CTM, predisposing them to damage during cricothyrotomy. A small cricothyroid artery, which is a branch of the superior thyroid artery, commonly crosses the upper portion of the CTM, anastomosing with the artery on the other side. External visible and palpable anatomic landmarks are used to locate the CTM. The laryngeal prominence (i.e., thyroid cartilage or Adam’s apple) and the hyoid bone above it are readily palpable. The CTM usually lies one to one and a half finger breadths below the laryngeal prominence. The cricoid cartilage is usually felt below the CTM. The importance of these landmarks is emphasized because it is disastrous to place the cricothyroid tube into the thyrohyoid space instead of the cricothyroid space.

Conscious effort to identify these landmarks reduces the possibility of committing this preventable error (see Fig. 30-6B). When the normal anatomy is distorted, identification of these landmarks is difficult. In these cases, the suprasternal notch may be used as an alternative marker. The small finger of the right hand should be placed in the patient’s suprasternal notch, followed by placement of the ring, long, and index fingers adjacent to each other in a stepwise fashion up the neck, with each finger touching the one below it. When the head is in the neutral position, the index finger is usually on or near the CTM.

IV Indications and Contraindications for Percutaneous Dilational Cricothyrotomy and Tracheostomy

A Cricothyrotomy

Cricothyrotomy is considered by many to be the standard approach to airway management when orotracheal or nasotracheal intubation and fiberoptic approaches have failed.^5,^18,⁴⁹ In the emergency room or prehospital setting,^50,⁵¹ cricothyrotomy is indicated for immediate airway control in patients with maxillofacial, cervical spine, head, neck, and multiple trauma and in patients in whom endotracheal intubation is impossible to perform or contraindicated. It is also used for the immediate relief of upper airway obstruction. In the operating room and in the ICU, the technique is indicated when conventional methods of intubation fail, such as in patients with traumatic facial injuries in whom other techniques of airway access are difficult or impossible to perform. Cricothyrotomy can also be used as an alternative to tracheostomy in patients with recent sternotomy who need airway access because the incision does not communicate with the mediastinal tissue planes. A needle-size cricothyrotomy with a Luer-Lok connection (for jet ventilation) or an anesthesia circuit–size connection is used for thoracic and other procedures involving the airways, especially the trachea, larynx, epiglottis, and base of the tongue.

Emergency cricothyrotomy has largely replaced emergency tracheostomy in the emergency department because of its simplicity, rapidity, and minimal morbidity, and percutaneous techniques are replacing surgical approaches.^52,⁵³ Use of emergency tracheostomy is limited and indicated only when laryngeal trauma may be accompanied by local edema, hemorrhage, subcutaneous emphysema, and damage to the thyroid or cricothyroid cartilage, precluding the performance of cricothyrotomy.

Cricothyrotomy is difficult to perform in pediatric patients because the larynx is smaller and their airways contain less fibrous supporting tissue and have only loose mucous membrane attachments in the airway inlet. Absolute and relative contraindications to cricothyrotomy are rare. Patients who have been intubated translaryngeally for more than 3 days (7 days according to many investigators) should not undergo cricothyrotomy because of the propensity to develop subglottic stenosis. Those with preexisting laryngeal diseases, such as cancer, acute or chronic inflammation, or epiglottitis, have a higher morbidity rate when cricothyrotomy is performed. Distortion of the normal neck anatomy by disease or injury may render the technique impossible. Normal anatomic landmarks may be distorted, making identification of the CTM difficult. Bleeding diathesis and a history of coagulopathy predispose the patient to hemorrhage, making the procedure extremely dangerous.

Cricothyrotomy is technically problematic to perform in the pediatric population and should be performed with extreme caution in children younger than 10 years. It should not be performed at all in children younger than 6 years unless a wire can be placed in the cricothyroid space and placement within the trachea can be verified.⁵⁴ Emergency tracheostomy under controlled conditions is the preferred choice.⁵⁵ Physicians who are unfamiliar or inexperienced with the technique are discouraged from performing the procedure without adequate supervision from a more senior or knowledgeable member of the medical team. Inexperience has been implicated as the most important factor contributing to cricothyroid complications.⁵⁶^–⁵⁸ Accuracy in identifying anatomic landmarks significantly depends on the physician’s experience but is poor overall, justifying the percutaneous technique in emergency conditions but supporting the use of ultrasound or video-enhanced visualization during elective procedures.

B Percutaneous Dilational Tracheostomy

PDT is mainly indicated in adult intubated patients (Box 30-1). In this patient population, the main indications for performing a PDT are the same as those for surgical tracheostomy:

• Preventing upper airway damage due to prolonged intubation

• Facilitating pulmonary toilet

• Providing a stable airway in patients requiring long-term mechanical ventilation and oxygen support

Several benefits of performing a tracheostomy in patients who require prolonged ventilation have been postulated and are supported by different levels of evidence.⁵⁹ Shorter ICU and hospital stays and less need for sedation are the most widely recognized benefits, whereas improved patient comfort, decreased work of breathing, improved oral hygiene, better long-term laryngeal function, faster weaning from mechanical ventilation, lower risk of ventilator-associated pneumonia, and lower mortality rates have also been reported but are supported by a lower level of evidence.⁵⁹

For the population of critically ill adult patients, PDT has been recommended as the procedure of choice for performing elective tracheostomy.^59,⁶⁰ PDT is recommended on the basis of a lower risk of wound infection, being able to perform it at the bedside rather than transferring critically ill patients to the operating room, and better cost-effectiveness compared with surgical tracheostomy.⁶⁰

Upper airway obstruction due to tumor, edema, infection, stenosis, or trauma represents the other major category of indications for tracheostomy. However, the overall safety of performing PDT in emergent situations and with unprotected airways is extremely controversial, and, in these conditions, the procedure should be reserved for selected patients and performed only by experienced providers.¹³ Anatomic suitability for this procedure must be determined preoperatively with the patient’s neck extended. Maximum neck extension increases the length of the cervical trachea and defines critical anatomic landmarks, such as the cricoid cartilage and sternal notch. A contraindication to the procedure is the inability to palpate the cricoid cartilage above the sternal notch. Similarly, the patient with a midline neck mass, high innominate artery, or large thyroid gland should undergo open surgical tracheostomy in the operating room. Coagulopathies should be corrected preoperatively. Ideally, the functional platelet count should be 50,000 or greater, and the international normalized ratio (INR) should be corrected to 1.5 or less. However, there have been reports of PDT safely performed in patients with severe thrombocytopenia.⁶¹

Patients requiring a positive end-expiratory pressure (PEEP) of 15 cm H₂O or higher are at high risk for complications such as subcutaneous emphysema and pneumothorax, and when possible, the procedure should be postponed for these patients. PDT is relatively contraindicated in nonintubated patients with acute airway compromise and in the pediatric population. For airway compromise in nonintubated patients, the risks are related to the length of the procedure and the inability to perform the procedure under direct endoscopic visualization without an ETT. Reasons to avoid PDT in children include the different airway anatomy and dimensions and the technical difficulties of maintaining adequate ventilation with a bronchoscope within a small ETT. Selected cases may present an exception to these contraindications, depending on the experience of the providers.¹³

V Percutaneous Dilational Cricothyrotomy

A Principles and Planning

This chapter focuses on percutaneous dilational techniques. Surgical cricothyrotomy and transtracheal catheter ventilation are discussed elsewhere in Chapter 31.

PDC is fast and usually easy to perform, even on patients with short necks or with spinal injury. Cricothyrotomy may be performed for elective airway management in trauma patients with technically challenging neck anatomy in lieu of tracheostomy, because it does not require a surgeon’s skill to gain airway access and has fewer operative and postoperative complications.⁶²^–⁶⁵ Several commercially available devices use this technology. These devices have in common the insertion of an airway catheter over a dilator, which is usually introduced over a guidewire. The guidewire is inserted through a needle or over-the-needle catheter (i.e., Seldinger technique) after making an initial skin incision. This technique, often used for the insertion of catheter introducer sheaths and central lines, is familiar to anesthesiologists. An airway over a dilator and guidewire is preferable because of the inherent safety of this technique and the ability to insert an airway of far greater diameter than the initial catheter.

The Nu-Trake device (Smiths Medical, Dublin, OH) introduces a housing that is similar to a dilator but made in two parts, with the needle loaded coaxially within it. After the needle is withdrawn, metal airways with obturators are serially introduced inside the housing until the desired diameter of tube is reached.

Several devices allow insertion of the dilator directly over a needle or directly into the skin incision. Although they lack the step of introducing a guidewire, they are included in this discussion because they require a skin incision and a dilator for insertion of the airway. PDC is gaining popularity in the emergency room, ICU, and operating room. It is similar to another popular ICU technique, PDT, which is an elective procedure.

Airways can be introduced rapidly by the Seldinger over-the-wire technique, which allows positive-pressure ventilation without modification of standard ventilation devices. Although the technique requires more time to perform than needle cricothyrotomy, it may be more effective in providing adequate ventilation and oxygenation.

Several cricothyrotomy sets (Melker Emergency Cricothyrotomy Catheter Set, Cook Critical Care, Bloomington, IN; Portex Mini-Trach II, Smiths Medical, Keene, NH; Pertrach, Pulmodyne, Inc., Indianapolis, IN) can be inserted by the PDC technique. The Melker device uses a skin incision, followed by insertion of a guidewire and insertion of a dilator and airway catheter (i.e., cricothyrotomy tube). The Melker set is available in 3.5-, 4.0-, and 6.0-mm-ID, uncuffed airway catheter sizes with lengths of 3.8, 4.2, and 7.5 cm, respectively. The Melker set also comes in a military version that is modified for direct insertion through an incision without the use of a guidewire (similarly, the Portex cricothyroidotomy kit [PCK] and Nu-Trake from Smiths Medical and the Quicktrach I and II from VBM are designed for single insertion without a guidewire). The 4.0-mm-ID airway catheter is 7.5 cm long. This allows use of a smaller-diameter tube of sufficient length for an adult neck. The military version is available with cuffed and uncuffed airway catheters. A cuffed, 5.0-mm-ID, 9-cm-long airway catheter also has been introduced into the market. These sets are available with adapters so that jet ventilators and conventional ventilators can be attached to the airway device. Pertrachs are available with 5.5- and 7.1-mm-ID cannulas.

The over-the-wire technique offers several advantages. Even if the over-the-needle or direct dilational technique, such as the Quicktrach, PCK, or the Melker military version, may be faster to perform, the reported difficulties and complications are greater. This is also true for the Nu-Trake device. Complications have included failure to gain airway access, multiple attempts at cannulation, mediastinal injury, pneumothorax, and severe bleeding. The wire-guided technique has the disadvantage of the wire kinking. Several clinical and cadaver-based studies have established the safety and efficacy of the percutaneous over-the-needle or -cannula, wire-guided technique.^42,⁶⁶^–⁷¹ For some of the devices, their use, diffusion, and success seem to have been influenced by local availability, original country of manufacturing, preliminary animal studies, and marketing, despite scarce clinical evidence of efficacy.

B Insertion Techniques

1 Percutaneous Dilational Cricothyrotomy Device

The PDC device manufactured by Melker contains a scalpel blade; a syringe with an 18-G over-the-needle catheter or a thin-walled introducer needle, or both; a guidewire; a dilator of appropriate length and diameter; and a polyvinyl airway catheter with or without a cuff (Fig. 30-7). A universal kit combines open cricothyrotomy and percutaneous tools in a single tray. (Although it defeats the concept of a percutaneous approach, it may be useful in remote or austere locations.) Detailed insertion instructions for this type of device are available from the manufacturer’s Website, brochure, and CD. A description of the Melker insertion technique (Fig. 30-8) follows:

1. Position the patient supine, and if there is no contraindication, slightly extend the neck by using a roll under the neck or shoulders. If cervical spine injury is suspected, properly immobilize the head and neck, and maintain a neutral position.

2. Open the prepackaged cricothyrotomy set, and assemble the components. Whenever possible and appropriate, use aseptic technique and local anesthetic.

3. Identify the CTM between the cricoid and thyroid cartilages.

4. Carefully palpate the CTM, and while stabilizing the cartilage, make a vertical or horizontal skin incision using the scalpel blade (can also be performed after the Seldinger technique). Make a stab incision (vertical or horizontal) through the lower third of the CTM. An adequate incision eases introduction of the dilator and airway, but the incision can follow the placement of the guidewire.

5. Attach the supplied syringe to the 18-G introducer needle–plastic catheter (over the needle technique) system (same that you would use to place an angio-catheter), or alternatively attach the syringe to the introducer needle only (having removed the plastic catheter) if you prefer or are concerned the plastic catheter may kink. Insert the syringe-needle-catheter or syringe-needle only, and advance it through the incision into the airway at a 45-degree angle to the frontal plane in the midline in a caudad direction. When advancing the needle forward, entrance into the airway can be confirmed by aspiration with the syringe resulting in free air return or air bubbles in a saline-filled syringe.

6. Remove the syringe and needle, leaving the plastic catheter or introducer needle in place. Do not attempt to advance the plastic catheter completely into the airway, which may result in kinking of the catheter and an inability to pass the guidewire. Advance the soft, flexible end of the guidewire through the catheter or needle and several centimeters into the airway.

7. Remove the plastic catheter or needle, leaving the guidewire in place.

8. Advance the handled dilator inside the airway catheter (single dilation if a preincision was made), tapered end first, into the connector end of the airway catheter until the handle stops against the connector. With other sets, insert the dilator to the recommended depth, or insert the dilator over the guidewire for a preinsertion dilation (recommended if a preincision was not made). Use of lubrication on the surface of the dilator may enhance the fit and placement of the emergency airway catheter.

9. Advance the emergency airway access assembly over the guidewire until the proximal stiff end of the guidewire is completely through and visible at the handle end of the dilator. Always visualize the proximal end of the guidewire during the airway insertion procedure to prevent its inadvertent loss into the trachea. Maintaining the guidewire position, advance the emergency airway access assembly over the guidewire with an in-and-out motion.

10. As the airway catheter is fully advanced into the trachea, remove the guidewire and dilator simultaneously.

11. If a cuffed tube is inserted, inflate it with 10 mL of air with the syringe provided.

12. Fix the emergency airway catheter in place with the cloth tracheostomy tape strip in a standard fashion.

13. Using its standard 15- to 22-mm adapter, connect the emergency airway catheter to an appropriate ventilatory device.

Figure 30-7 A, Melker cuffed cannula inserted in a model. B, Melker cricothyrotomy kit, which consists of the items shown and a tracheostomy cloth tape strip for fixation of an airway catheter.

(Courtesy of Cook Medical, Bloomington, IN.)

Figure 30-8 A to H, Melker insertion technique.

(From Melker emergency cricothyrotomy sets: Suggested instructions for placement, instruction pamphlet. Cook Critical Care, Bloomington, IN, 1988.)

5 Percutaneous Dilational Cricothyrotomy

a Arndt

The Arndt cricothyrotomy cannula (Cook Medical) is technically a percutaneous dilational wire-guided cannula designed for transtracheal jet ventilation (Fig. 30-9; see Fig. 30-3).

Figure 30-9 Arndt cricothyrotomy cannula components.

(Courtesy of Cook Medical, Bloomington, IN.)

b Pertrach

The Pertrach (Fig. 30-10) is similar to the previously described devices, except that the guidewire and dilator are a single unit. The introducer needle must be split after the distal end of the guidewire is advanced so that the dilator can be introduced (Fig. 30-11). This is cumbersome, especially in emergency situations, and requires the guidewire and dilator to be advanced far down the airway. A study in cadavers showed equal success for PDC with the Pertrach and surgical cricothyrotomy. Surgical cricothyrotomy was faster, but it was impossible to predict whether bleeding complications would have been higher with the surgical cricothyrotomies. The manufacturer and the users have reported problems with the needle, which is occasionally difficult or impossible to split.

Figure 30-10 Pertrach cannula.

Figure 30-11 Pertrach technique steps.

c Nu-Trake

The Nu-Trake device has a rigid airway and may be difficult to secure. The Nu-Trake requires far greater insertion forces than other devices, often resulting in the introducer-stylet embedding in the posterior wall of the trachea. The device has had frequent air leaks, and the lumen has a tendency to occlude on the posterior wall of the trachea. Subcutaneous emphysema, cricoid cartilage injury, cricotracheal ligament perforation, posterior wall perforation, and incidental submucosal airway hemorrhage have also been described.

d Quicktrach and Portex Cricothyroidotomy Kit

The Quicktrach (Rüsch, VBM) (Fig. 30-12) and PCK (Portex) (Fig. 30-13) offer a single-step technique that is preceded by a skin incision, proceeds over a needle, and is not guided by a wire. The devices are technically faster to use but overall are less safe, carrying a higher complication rate (e.g., multiple attempts, inability to advance the cannula, false pas sage) than the Seldinger technique. The PCK (Fig. 30-14) has a Veress needle system, which is designed to detect pressure on the posterior wall of the trachea. The PCK is inserted directly through the CTM after a skin incision (Fig. 30-15).

Figure 30-12 Quicktrach I standard set.

(Courtesy of Teleflex Medical, Research Triangle Park, NC.)

Figure 30-13 Quicktrach II cricothyrotomy set.

(Courtesy of VBM Medical, Noblesville, IN.)

Figure 30-14 Portex cricothyroidotomy kit.

(Courtesy of Smiths Medical, Dublin, OH.)

Figure 30-15 Portex cricothyroidotomy kit (PCK) insertion technique.

(Modified from Smiths Medical, Dublin, OH.)

The fast access that these systems provide can be life-saving in remote locations and in treating a severely damaged airway, outweighing the potential complications. However, their use in less emergent situations may be questionable, especially by first-time users.

VI Percutaneous Dilational Tracheostomy

A Principles and Planning

PDT is an accepted alternative to surgical tracheostomy, and it is gaining in popularity, particularly for patients in the ICU who have been intubated or are expected to need endotracheal intubation for extended periods.^59,⁷²^–⁷⁶ PDT is a mostly elective procedure, although there have been reports of PDT safely performed in selected emergent situations.¹³ Cricothyrotomy is a preferred route for emergent airway access.

As with any procedure, proper planning begins with a history and physical examination, and palpation of critical landmarks, such as the cricoid cartilage and sternal notch, is mandatory. The neck must be inspected to exclude a high innominate artery or midline neck mass. Preoperative testing is minimal and includes a recent chest radiograph and serum determinations of hemoglobin, prothrombin time (PT), partial thromboplastin time, and platelets. The INR, which is calculated to reflect the PT, best reflects coagulation status. Although 1 is a normal value, an INR corrected to less than 1.5 is acceptable. Because bleeding is usually minimal, crossmatching of blood cell units is unnecessary, even in the presence of a low hemoglobin level.

A fully equipped difficult airway cart should be available nearby in the event of accidental extubation during the procedure. In patients with thick, large necks, consideration should be given to placement of an extra-long tracheostomy tube to prevent accidental decannulation or displacement into the pretracheal soft tissues. Ideally, four people are required for the procedure, including the operating physician, a resident or critical care colleague to perform the bronchoscopy, a respiratory technician or other qualified staff member to assist in adjusting ventilator settings and to hold the ETT firmly in position, and a nurse to administer medications, monitor vital signs, and assist in obtaining necessary materials and instruments. The surgeon and necessary instruments usually are positioned to the patient’s right, the respiratory technician to the left, and the bronchoscopist at the head of the bed.

Many kits are commercially available for this procedure. The most widely used are those based on the original Ciaglia technique (Fig. 30-16A) and subsequent modifications that led to the single-dilator kits. Included in this category is the Ciaglia Blue Rhino G2 Advanced Percutaneous Tracheostomy Kit (Cook Medical), the Portex ULTRAperc Single-Stage Dilator (Smith Medical), and the Ciaglia Blue Dolphin balloon percutaneous tracheostomy kit (Cook Medical).

Figure 30-16 A, Ciaglia kit. B, Detailed instructions (1 to 8) for insertion of the Ciaglia percutaneous tracheostomy set.

(Courtesy of Cook Critical Care, Bloomington, IN.)

The Portex Griggs Percutaneous Dilation Tracheostomy Kit (Smiths Medical), based on the Griggs guidewire dilating forceps technique, is widely used. Detailed insertion instructions for these types of devices are available from the manufacturers’ Web sites, brochures, and CDs. The following paragraphs offer a brief description of the general principles of appropriate planning for these procedures and detailed instructions on how to perform PDT with the single-dilator technique.

The instruments should be placed on a stand over the patient’s bed in the order in which they will be used. An appropriately sized bronchoscope with a suction port must be chosen to fit within the ETT or nasotracheal tube while allowing adequate ventilation. A pediatric bronchoscope must be used when the ETT has an ID of less than 7.0 mm. A video monitor, if available, may be connected to the bronchoscope, allowing full visualization of the intratracheal portion of the procedure by the operating surgeon and staff. Any procedure involving manipulation of the trachea is highly stimulating to the patient and requires adequate local anesthesia supplemented by intravenous sedation. Local anesthesia, consisting of 1% or 2% lidocaine with a 1 : 100,000 solution of epinephrine, is used for generous infiltration of the incision site down to the level of the trachea. Topical anesthesia in the form of 2% to 4% lidocaine may be injected through the bronchoscope and is useful in decreasing the cough reflex during intratracheal instrumentation. Intravenous anesthesia is required, and the particular drug combination depends on the patient and the institution. Frequently used medications include midazolam, fentanyl, remifentanil, propofol, and dexmedetomidine. The presence of an anesthesiologist is recommended, but this depends on the hospital setting and availability. Care should be exercised in managing the ETT, performing the bronchoscopy, and administering drugs, particularly in elderly patients, because large fluctuations in blood pressure and heart rate may occur even with small doses. Muscle relaxation is recommended to facilitate procedures.

B Insertion Techniques

1 Seldinger Guidewire and Single-Dilator Kit

1. The patient is positioned as for conventional tracheostomy with the head extended on the neck, and anatomic landmarks are marked (see Fig. 30-6, B). A standard preparation and drape are applied.

2. The skin and subcutaneous tissues are infiltrated with 2% lidocaine and a 1 : 100,000 solution of epinephrine one or two finger breadths below the previously palpated and marked cricoid cartilage (Fig. 30-17, A).

3. A 1.5-cm horizontal skin incision is made, and the subcutaneous tissues are bluntly separated with a curved hemostat. No attempt is made to manipulate the strap muscles or thyroid gland.

4. At this point, the fiberoptic bronchoscope (FOB) is advanced until its tip is aligned with the lower margin of the ETT (advance in a supraglottic device until the cricoid is visualized). External manipulation and transtracheal illumination can facilitate structure recognition.

5. Any ties securing the ETT are loosened, and the FOB and ETT are withdrawn slowly in unison until the incision is maximally transilluminated.

6. The FOB, which may be connected to a monitor, is maintained in this position throughout the procedure, allowing direct visualization of every step.

7. The 16- or 17-gauge introducer needle is inserted between the first and second or second and third tracheal rings (see Fig. 30-17, B).

8. A midline intercartilaginous placement is verified bronchoscopically.

9. The needle is withdrawn, leaving the overlying catheter sheath through which the guidewire can be inserted (see Fig. 30-17, C and D).

10. The sheath is removed and replaced by a 14-F introducer dilator, which is advanced over the guidewire (several times); this maneuver enlarges the tracheal aperture sufficiently to allow easy placement of the 12-F guiding catheter.

11. The guiding catheter and guidewire are left in place and form the backbone over which the single dilator is used.

12. The single dilator with the hydrophilic coating moistened is advanced over this unit (see Fig. 30-16, B), several times if necessary, until resistance is minimal. The chosen depth of dilation also depends on the size of the cannula to be inserted.

13. The dilator is replaced by the preloaded tracheostomy tube, which is advanced into the trachea. Some resistance may be encountered at the interface between the dilator and tracheostomy tube.

14. The guidewire, guiding catheter, and dilator are removed and replaced by the inner cannula.

15. The ventilatory apparatus is connected to the tracheostomy, which is secured with four corner sutures.

16. When ventilation is adequate, the ETT is removed while examining the vocal folds. A postoperative chest radiograph is obtained to rule out a pneumothorax. In a patient with a large, thick neck, a longer tracheostomy tube should be used to prevent accidental displacement of the tube into the pretracheal soft tissue. In the event of accidental decannulation within 5 days of the procedure, the ICU staff is advised to reintubate the patient orally rather than attempt to reinsert the tracheostomy tube.

Figure 30-17 Use of a single dilator. A, Local anesthesia. B, Introducer needle, C, Guidewire insertion in a clinical case. D, Diagram of guidewire insertion.

Precautions in the performance of this technique include the following:

• Always confirm access into trachea by air bubble aspiration.

• Maintain safety positioning marks of the guidewire, guiding catheters, and dilator during the dilating procedure to prevent trauma to the posterior wall of the trachea.

• Tracheostomy tubes should fit snugly to the dilator for insertion. Generous lubrication of the surface of the dilator enhances fit and placement of the tracheostomy tube.

2 Ciaglia Blue Rhino G2 Advanced Percutaneous Tracheostomy Kit

The Ciaglia Blue Rhino G2 Advanced Percutaneous Tracheostomy Kit (Cook Medical) (Fig. 30-18, A) has a curved dilator that is advanced over a guiding catheter and creates a tracheostomy opening in one pass, obviating the need for multiple dilators as with previous kits (see Fig. 30-18, B). The softness of the dilator, the hydrophilic coating, and the one-passage technique are the main advantages of this widely used percutaneous tracheostomy system, which has been at least as safe as the PDT techniques in multiple trials.^40,⁷⁷^–⁸¹

Figure 30-18 A, Ciaglia Blue Rhino G2 tray. B, Blue Rhino percutaneous tracheostomy dilator.

(Courtesy of Cook Medical, Bloomington, IN.)

3 Ciaglia Blue Dolphin Balloon Percutaneous Tracheostomy Kit

The Ciaglia Blue Dolphin Balloon percutaneous tracheostomy kit (Cook Medical) offers an improvement on the single-dilator PDT technique. This system combines balloon dilation and tracheal tube insertion in a single step (Fig. 30-19). The underlying principle is that balloon dilation should minimize pressure on the anterior tracheal wall and deliver an even and controlled radial dilation. Given the novelty of this device, data from the literature are insufficient to determine any advantage of this system compared with established methods and devices.

Figure 30-19 Ciaglia Blue Dolphin balloon percutaneous tracheostomy introducer.

(Courtesy of Cook Medical, Bloomington, IN.)

4 Portex ULTRAperc Single-Stage Dilator

The Portex ULTRAperc Single-Stage Percutaneous Dilation Tracheostomy Kit (Smiths Medical) is based on the widely accepted Seldinger guidewire technique. The kits are available with the Blue Line Ultra Suctionaid Tracheostomy Tube that features an integrated suction lumen for removal of pooled secretions (Fig. 30-20).

Figure 30-20 A, Portex ULTRAperc kit. B, Insertion of the ULTRAperc cannula with a handle introducer.

(A, Courtesy of Smiths Medical, Dublin, OH.)

In a study comparing the ULTRAperc device with the Blue Rhino in mannequin and porcine models, dilation with the ULTRAperc set was subjectively easier and required less force, and the time for tracheostomy tube insertion was shorter.⁸² The investigators suggest that the ULTRAperc set is subjectively easier to use, quicker, and causes less anterior-posterior tracheal compression during tracheostomy tube insertion compared with the Blue Rhino set in mannequin and porcine airway models. This advantage may be from the tracheostomy tube introducer in the ULTRAperc set that allows smooth passage of the tracheostomy tube through the dilated stoma.

5 Portex Griggs Percutaneous Dilation Tracheostomy Kit

The Portex Griggs Percutaneous Dilation Tracheostomy Kit (Smiths Medical) features guidewire dilating forceps that are central to the Griggs PDT technique (Fig. 30-21). Dilating forceps specially designed to slide along a prepositioned guidewire are used to open pretracheal tissue and the anterior tracheal wall in preparation for tube insertion. Use of the forceps causes less compression compared with the cone-shaped, single-stage dilators. In a prospective, randomized comparison of progressive-dilational versus forceps-dilational percutaneous tracheostomy,⁸³ the progressive-dilational tracheostomy took longer, caused more hypercapnia, and caused more minor and major difficulties than forceps-dilational tracheostomy. We agree that the guidewire dilating forceps technique is safe and easy to learn, and it may be quicker than the progressive-dilational technique. Sometimes, the forceps cannot be inserted to the full length due to thick subcutaneous tissue of the anterior neck. Switching from forceps to a progressive dilator allows completion of the procedure without complications.^31,⁸⁴ The Portex Griggs Percutaneous Dilation Tracheostomy Kit also may be used in combination with Suctionaid tracheostomy tubes with an integral suction lumen to aid suctioning of secretions from above the cuff.

Figure 30-21 A, Portex Griggs forceps used for dilatation during surgery. B, Diagram of forceps dilatation.

(B, Courtesy of Smiths Medical, Dublin, OH.)

6 Percutwist

Increased control over the dilating maneuver from start to finish is one of the advantages of the Percutwist (Rüsch-Teleflex Medical) (see Fig. 46-19 in Chapter 46). Another is the possibility to lift the anterior tracheal wall, facilitating the endoscopic view of the dilation site during the procedure. Gradual application of the forces applied to produce dilation may increase the safety of this technique, although cases of posterior tracheal wall injury have been reported.^78,⁸⁵

7 Translaryngeal Tracheostomy Kit

The Translaryngeal Tracheostomy Kit (Mallinckrodt, Mirandola, Italy) is used mostly in European countries to perform translaryngeal tracheostomy according to the technique introduced by Fantoni in 1997. The critical steps of this procedure and use of this system are summarized in Figure 46-16 (see Chapter 46). Percutaneous tracheostomy has a learning curve and requires appropriate training. All studies comparing different methods should take into consideration potential differences in training of the personnel performing PDT with each proposed technique. Different environments and patient characteristics may dictate the choice of a specific technique or determine the preference for a specific system.

8 Controversies and Questions

a Use of Bronchoscopy and Ultrasound

The issue of bronchoscopy has been hotly debated in the literature over the past 2 decades. Those in favor argue that it is easy to perform and adds to the safety of the procedure by significantly decreasing or eliminating the risk of false passage, pneumomediastinum, pneumothorax, and subcutaneous emphysema. Bronchoscopy allows early detection and suctioning of intratracheal blood and secretions. The bronchoscope also allows proper midline needle placement between the second and third tracheal rings and prevents injury to the posterior tracheal wall.

Opponents argue that bronchoscopy increases the length and cost of the procedure and does not add to safety in experienced hands. Moreover, the presence of the bronchoscope within the ETT may result in CO₂ retention and difficulty ventilating the patient. The accumulated weight of evidence in the literature points to the advantages of bronchoscopy for safety reasons.^86,⁸⁷ Nonetheless, a large meta-analysis was not able to demonstrate a clear advantage of bronchoscope-guided procedures in terms of decreasing overall mortality and major perioperative complications.⁸⁸

Ultrasound has been proposed as a useful tool to identify the anatomy of airway, blood vessels, and other structures, such as the thyroid gland and isthmus. Ultrasound has in some cases replaced bronchoscopic guidance.⁸⁹ However, a combination of the two (depending on resource availability) may offer better results. Whether ultrasound can reduce the incidence of tracheal-innominate fistulas (a rare but deadly complication) needs further investigation.⁹⁰

b Patient’s Habitus

Controversy exists regarding the suitability of percutaneous tracheostomy in obese patients. Obesity may preclude adequate palpation of critical landmarks and increase the risk of false passage or accidental decannulation into the soft tissues of the neck. Optimal positioning of the neck usually permits localization of the cricoid cartilage and sternal notch. Vigorous spreading of the subcutaneous tissues during the procedure facilitates palpation of the tracheal rings for precise needle placement. The risk of false passage may be addressed by always using a bronchoscope and ensuring step-by-step visualization.

Accidental decannulation in these patients is more likely to occur because of the displacement of the tube in the abundant soft tissues. Using proximally extended tracheostomy tubes dramatically reduces the risk of this complication. Ben Nun and colleagues presented a case series of 154 critically ill adult patients in whom percutaneous tracheostomy using the Griggs technique was performed at the bedside.⁹¹ Eighteen of these patients had a short, fat neck as their only risk factor for PDT. Short, fat neck was defined as a neck circumference greater than 46 cm, with a distance between the cricoid cartilage and the sternal notch of less than 2.5 cm and distance between the cricoid cartilage and the pretracheal soft tissues of more than 2.5 cm. No complications were reported in this group. Heyrosa and coworkers reported their results for a series of 89 obese patients (body mass index [BMI] >35 kg/m²) undergoing PDT and 53 obese patients (same BMI) undergoing open tracheostomy, and they found the same complication rate (6.5%) for the two groups.⁹²

Aldawood and colleagues performed PDT in 50 obese patients, mostly without bronchoscopic guidance.⁹³ They reported an increased rate of major complications compared with nonobese patients (12% versus 2%, P = 0.04) but a similar rate of minor complications for the two groups.⁹³ They defined obesity as a BMI of 30 kg/m² or higher. The most frequent major complication was “procedure aborted, not otherwise specified,” but no surgical conversion, pneumothorax, or death occurred in either group. The investigators concluded that PDT could be performed safely in most obese patients.

In a prospective evaluation of endoscopic PDT in 500 consecutive intubated adults in the ICU, patients with a BMI of 30 kg/m² or greater had a significantly greater (P < 0.06) number of complications (15%) than the patients (8%) with a BMI less than 30 kg/m².⁹⁴ This risk was even more significant for patients with a BMI of 30 or more who were also in ASA physical status class 4 (11 of 56 [20%]) (P < 0.02). Byhahn and colleagues reported an extremely high complication rate (43.8%) for 73 obese patients and found that obese patients (BMI >27.5 kg/m²) had a 2.7-fold increased risk for perioperative complications and a 4.9-fold increased risk for serious complications compared with nonobese patients.⁹⁵ The researchers concluded that percutaneous tracheostomy in obese patients was associated with a considerably increased risk for perioperative complications, especially for serious adverse events. Comparison of the results and conclusions from these studies is problematic because of the different criteria used in defining obesity, the dissimilar primary and secondary end points, and the use of different percutaneous techniques for PDT.

VII Postoperative Considerations

A Cricothyrotomy

Cricothyrotomy is usually performed emergently to secure a difficult airway, but it can be performed electively.⁷ When cricothyrotomy is performed under less than ideal circumstances, it should be considered a temporary measure, and when the patient is stabilized, endotracheal intubation with or without an FOB or a tracheostomy should be performed. The FOB affords an opportunity to evaluate the airway, especially at the site of the cricothyrotomy. The cricothyrotomy site should be examined frequently for signs of infection, and all patients should have a careful neurologic and airway evaluation before discharge from the hospital to ensure that there has been no damage to the vocal cords or other proximate structures. There is no consensus of opinion on what work-up is necessary after emergency cricothyrotomy, but any complaints by the patient of difficulty swallowing or phonating should be carefully evaluated. Complication rates from properly performed emergent cricothyrotomy are acceptably low.

B Percutaneous Tracheostomy

With the termination of the intense stimulation produced by the procedure, the effects of the sedation may become more pronounced, and particular care must be taken in monitoring for changes in vital signs such as hypotension, tachycardia, or oxygen desaturation. In some cases, pharmacologic intervention may be required. Excess secretions or blood may compromise ventilation and result in an oxygen saturation drop, requiring suctioning. A postoperative chest radiograph is required to ensure the absence of pneumothorax and pneumomediastinum.

Many of these patients have copious secretions from the tracheostomy site because of their associated pulmonary condition. A tracheostomy tube with an inner cannula facilitates care and hygiene and ensures added safety by easy removal if obstruction from secretions occurs. The percutaneous technique is primarily dilational with minimal tissue dissection, resulting in a tighter tract and a very snug fit of the tracheostomy tube. The technique does not allow placement of traction sutures at the level of the trachea. Because of these factors, the patient should be reintubated orally in the event of accidental decannulation within the first 5 days of the procedure, while the tract is still relatively immature. Attempts at replacing the tracheostomy tube in an emergent situation may cause bleeding, the creation of a false passage, pneumomediastinum, hypoxia, or death.

1 Complications and Outcome Data

a Cricothyrotomy

The reported complication rate is 6% to 8% for elective cricothyrotomy and 10% to 40% for emergent procedures.^96,⁹⁷ The morbidity and mortality rates for elective cricothyrotomy are similar to those for elective tracheostomy. Boyd and colleagues found 10 complications (6.8%) in 147 cricothyrotomies, but no differentiation was made between elective and emergency procedures. In 1976, Brantigan and Grow reported a 6.1% complication rate for 655 cases, most of which were correctable and self-limited, and this compared favorably with the complication rate associated with tracheostomy. The same investigators implicated the presence of acute laryngeal pathology (especially from prolonged intubation before cricothyrotomy) as the predisposing factor in the subsequent development of subglottic obstruction.⁹⁸

Adverse effects of cricothyrotomy can be categorized as those that occur early and those that occur late in the postoperative period. Early complications include asphyxia related to failure to establish the airway, hemorrhage, improper or unsuccessful tube placement, subcutaneous and mediastinal emphysema, prolonged procedure time, pneumothorax, and airway obstruction. Esophageal or mediastinal perforation, vocal cord injury, aspiration, and laryngeal disruption may also occur.⁹⁹ Long-term complications include tracheal and subglottic stenosis (especially in the presence of preexisting laryngeal trauma or infection), aspiration, swallowing dysfunction, tube obstruction, tracheal-esophageal fistula, and voice changes.¹⁰⁰ Voice change is the most common complication, occurring in up to 50% of cases.²⁰ Voice problems include hoarseness, weak voice, or decreased pitch. The voice dysfunction may be caused by injury to the external branch of the superior laryngeal nerve, decreased cricothyroid muscle contractility, or mechanical obstruction related to narrowing of the anterior parts of the thyroid and cricoid cartilages.¹⁰¹ Infection, late bleeding, persistent stoma, and tracheomalacia have also been reported. Although subglottic stenosis is the most frequently reported major complication after cricothyrotomy,¹⁰² it is rare after tracheostomy. Pneumothorax and major blood vessel erosion are also associated with tracheostomy. Other complications associated with tracheostomy include mediastinal emphysema, accidental extubation, cardiac arrest, and death.

The complication rate for cricothyrotomy is higher in the pediatric population. Pneumothorax is the most common complication in children (5%to 7%) and is rarely seen in adults. Between 1% and 2% of adults develop subglottic stenosis after tracheostomy, compared with 2% to 8% of children. Children undergoing cricothyrotomy have a mortality rate up to 8.7%. Prehospital cricothyrotomy performed by emergency medical services (EMS) personnel carries a higher risk of morbidity than the in-hospital procedure. Spaite and Joseph reported an overall acute complication rate of 31% for 20 emergency patients. Failure to secure the airway accounted for the major complication rate (12%). Minor complications included right main stem intubation, infrahyoid placement, and thyroid cartilage fracture. Sixty surgical cricothyrotomies performed by trained aeromedical system personnel had a complication rate of 8.7%.¹⁰³ These complications included significant hemorrhage or soft tissue hematoma and incorrect placement. All the previous complications are from surgical or mixed surgical and percutaneous cricothyrotomy studies. Problems and complications associated specifically with percutaneous cricothyrotomy include difficulties with insertion, esophageal or mediastinal misplacement, and bleeding.¹⁰⁴ The overall reported complication rate is 5%. Complications included CTM calcification, blockage by secretions, dystrophic ossification, and heterotrophic bone formation. Displacement of the tube into the mediastinum may occur and can cause emphysema, respiratory distress, and pneumothorax.¹⁰⁵ Bleeding occurs in 2% of cases, but significant hemorrhage requiring surgical intervention is rare. The Seldinger technique appears to lessen the incidence of bleeding and promote a more precise technique of insertion.¹⁰⁶

b Percutaneous Tracheostomy

Most studies report excellent success and low complication rates with PDT.^90,^107,¹⁰⁸ Since PDT became common clinical practice, data on the utility of this procedure and its potential advantages over standard tracheostomy have been reported in many publications.^36,^73,^90,^107,^109,¹¹⁰

Potential complications of tracheostomy, whether performed openly or percutaneously, can be described as intraoperative or postoperative and as early or late; they are listed in Box 30-2. The overall complication rate reported for PDT in large studies, systematic reviews, and meta-analyses ranges from about 6% to 15%.^85,¹¹¹^–¹¹⁴ It has been suggested that bronchoscopy-guided PDT might have a lower incidence of complications compared with PDT performed without bronchoscopy,^86,^87,¹¹⁵ but the data on this issue are mixed, and other studies have not confirmed this hypothesis.⁸⁸ Among intraoperative complications, premature extubation and bleeding are most concerning and reported more frequently. Early postoperative complications include tube malpositioning, bleeding, subcutaneous emphysema, and pneumothorax. The most significant late complications are glottic and tracheal stenosis and stomal infection. A rare but deadly late complication is tracheal-innominate fistula.⁹⁰ Whether this complication is related to any specific technique or anatomic variants (e.g., tracheostomy performed too low, cannula not appropriately chosen, variant blood vessel anatomy) must be determined, as well as the possible contribution of ultrasound to reduce the incidence. However, because the incidence of this complication is low, a very large number of observations would be required to evaluate the value of an intervention to decrease it.

The differences between techniques used, operators’ experience, patient selection criteria, and indications and timing of the procedures make it difficult to perform an accurate comparison of the data available from the literature on the overall safety of PDT with that for standard open tracheostomy. However, there seems to be a significant amount of evidence to support that PDT has a lower incidence of peristomal bleeding and wound infection compared with open tracheostomy.⁷³^–⁷⁶ ⁸⁸ For these reasons, it has been advocated that PDT should be considered the procedure of choice for performing elective tracheostomy in critically ill patients.^74,⁸⁸ The decreased incidence of bleeding may be related to the lack of sharp dissection and the tamponade effect of the dilator. The much smaller wound created with the PDT technique reduces the surface area available for bacterial colonization and may explain the low rate of wound infection. Late outcome studies evaluating serious long-term complications associated with PDT indicate that the incidence of clinically significant tracheomalacia or stenosis requiring corrective intervention is low.¹¹⁶

After decannulation, 16 patients were evaluated by means of physical examination, standardized interviews, and fiberoptic laryngotracheoscopy. The subjective rating was good for all patients. Laryngotracheoscopy showed incidental tracheal changes in two patients consisting of soft tissue swelling and a membranous scar, respectively. Neither of these findings required treatment.¹¹⁷ Histologic studies were conducted on 21 laryngotracheal specimens from patients who had undergone PDT or standard open tracheostomy. In the percutaneous group, cartilage fractures associated with a strong inflammatory response were found in one third of cases, compared with a more limited inflammatory response in the standard group. There was no clinical evidence of laryngotracheal stenosis in either group.

Carrer and associates, in a prospective observational study of 181 ICU patients receiving PDT over a 6-year period, reported a 0.7% rate of tracheal stenosis requiring tracheal stent placement and a 1.4% rate of recurrent granuloma of the stoma that was treated with laser resection. Late decannulation seemed the major risk factor for these infrequent but clinically significant late complications.¹⁰⁷

2 Practical Applications of Cricothyrotomy

The superiority of the percutaneous technique over the surgical technique has turned attention toward the different cricothyrotomy kits available and their applications, success rates, and complications. An over-the-needle, wire-guided dilation technique is safer and adaptable to various practitioners (with different training time and specialties) and is still relatively fast. Over-the-needle techniques that do not use a guidewire, even if often reported to be faster and easier, can result in higher complication rates.

Another important issue is establishing indications based on patients’ injuries and habitus and on clinical scenarios.^118,¹¹⁹ Percutaneous techniques are increasingly used in the prehospital setting and for major facial injuries, neck abnormalities, or challenging anatomy. Many patients can be assisted or ventilated with a bag-valve-mask if definitive cricothyrotomy is performed, and they can be jet ventilated or ventilated mechanically if a needle cannula has been placed.

Cricothyrotomy is an important tool for managing the impossible airway or the threatened airway, and it often is the last and only way to avoid anoxia. In the previous edition of this textbook, a simplified protocol was proposed for prehospital emergency trauma airway control (Fig. 30-22). The protocol can be expanded by including an in-hospital approach (see Fig. 30-23 and the Difficult Airway Society’s “cannot ventilate, cannot intubate” scenario (http://www.das.uk.com/guidelines/cvci.html) or the ASA algorithm.⁴⁹ Both scenarios converge on an emergency pathway, in which the option of awake airway control or awakening the patient is not possible. In this emergency pathway, as interpreted by a modified ASA difficult airway algorithm (Fig. 30-24), cricothyrotomy performed surgically or percutaneously plays a fundamental role.

Figure 30-22 Emergency airway protocol for prehospital care. B-V-M, Bag-valve-mask; NT, nasotracheal; OT, orotracheal.

Figure 30-23 The Difficult Airway Society cannot intubate algorithm.

(Courtesy of the Difficult Airway Society, London, United Kingdom.)

Figure 30-24 Modified American Society of Anesthesiologists cricothyrotomy airway algorithm.

(Modified from the American Society of Anesthesiologists, Park Ridge, IL.)

When dealing with difficult airways, planning includes ventilation and intubation. Regardless of the techniques and devices that may offer assistance with bag-mask ventilation or intubation, if one or the other fails, a supraglottic device is the first alternative to further attempts to intubate and bag-mask ventilate, and the last is an invasive airway approach (i.e., cricothyrotomy).

In the past few years, many changes in airway management occurred as a result of better airway equipment availability and implementation of airway protocols. As observed by Timmerman and colleagues and Combes and associates, cricothyrotomy is rare, even in emergency airway conditions, if an airway protocol is used (assuming no major neck trauma).^120,¹²¹ However, a careful reading of the literature shows a significant number of complications that may question the underuse of more invasive techniques and argue for the earlier use of these techniques, depending on the level of training, the setting, and clinical conditions. Appropriate training is fundamental to maintain proficiency in the technical skills required to perform these invasive procedures safely, rapidly, and effectively.

VIII Training Models

Because PDC is rarely performed, there is a need for quality teaching and training aids.^25,¹²² Although the technique closely mimics over-the-wire vascular insertion methods, it is sufficiently different that anesthesiologists ideally should practice on a regular basis.^27,⁵⁷ Simple and inexpensive models can be made for training residents and inexperienced personnel, as well as maintaining the skills and proficiency of the trainees and experts.

Of the available animal models, dogs appear to be most similar to humans. The canine CTM, muscles, and cricothyroid area are similar to those in humans. The tracheal dimensions of the 25-kg dog are comparable to those of the adult human.² Cricothyrotomy has been performed on other animals, including pigs, sheep, and goats. The larynx is significantly smaller in these animal models, and 3.5- or 4.0-mm-ID sets must be used for teaching. In pigs, attempts to pass a needle or over-the-needle catheter into the cricothyroid space may result in hitting cartilage. The space can be entered only by directing the needle cephalad, not caudad. Dissection of the larynx revealed a projection on the inferior surface of the thyroid cartilage that articulated with the cricoid cartilage. This cornu had been previously described and had to be removed to perform cricothyrotomy studies.¹⁰¹ The pig trachea model (professionally isolated and prepared) is used for airway training and is combined with manikin simulations for the education of residents and faculty in surgical and percutaneous cricothyrotomy in teaching institutions, workshops, and airway management courses (e.g., Society for Airway Management, Difficult Airway Workshop, American Society of Anesthesiologists Annual Meeting).

Fresh and embalmed cadaver specimens can be used.^67,¹²³^–¹²⁵ The former are superior because the laryngeal structures of embalmed specimens are somewhat constricted because of muscle contraction, and it may be more difficult to discern the cricothyroid space. Mannequins can also be an acceptable model, and several products are available, but cheaper and simple models can also be used for skill maintenance and simulation.¹²⁶ Simulation and practice-workshops are used in teaching programs or as part of dedicated airway management courses or meetings.^56,¹²⁷^–¹²⁹

IX Miscellaneous Considerations

A Cuff Pressure

Tracheostomy tube cuffs are used to create a seal against the tracheal mucosa, thereby minimizing aspiration, and to facilitate positive-pressure ventilation by preventing leakage of air. Tracheal stenosis from low-volume, high-pressure, low-compliance cuffs was a major complication of tracheostomy during the 1960s. These cuffs may exert pressures as high as 180 to 250 mm Hg on the tracheal mucosa, far in excess of the normal capillary perfusion pressures of 20 to 30 mm Hg. The result is a time-related, progressive ischemic injury ranging from inflammatory changes to chondronecrosis and tracheal stenosis or tracheomalacia. With the accumulated evidence attesting to the deleterious effects of low-volume, high-pressure cuffs, there has been a gradual shift in the past 3 decades toward the use of high-volume, low-pressure cuffs because they are safer.

The transition in the 1970s to high-volume, low-pressure cuffs decreased the incidence of cuff-related tracheal stenosis by 10-fold because of the ability of the cuff to seal the airway at pressures below the mucosal capillary perfusion pressure. These cuffs inflate symmetrically, adapt to the tracheal contour, and allow pressure distribution over a wide area. The risk of overinflation with resultant high intracuff pressures may be minimized by the following:

• Having a pressure-controlled cuff with a pressure pop-off valve, which prevents inflation beyond 20 mm Hg (although less than 20 mm Hg has been associated with increased risk of leakage of bacterial pathogens around the cuff into the lower respiratory tract)¹³⁰

• Regular measurement of intracuff pressure with a manometer attached to a three- or four-way stopcock (the latter gives more accurate results)

• Cuff deflation for as long as safely possible in patients who do not require mechanical ventilation

B Infections

1 Risk Factors

a Disruption of Host Defenses

Performing a tracheostomy requires a skin incision, thereby disrupting this highly effective natural barrier to infection. The resultant open surgical wound provides a wide surface area for colonization, which may occur from surrounding skin, preexisting infected pulmonary secretions, aspiration of oropharyngeal secretions, or instrumentation or handling of the tracheostomy tube.

The nose, paranasal sinuses, and pharynx, where filtration and humidification and local leukocyte antibacterial activity occur under normal circumstances, are all bypassed in the patient with a tracheostomy. Impaired vocal fold adduction in patients with tracheostomies and the presence of the tube prevent generation of an effective cough. Oropharyngeal secretions, often colonized with potentially pathogenic gram-negative organisms, are ineffectively cleared or swallowed, allowing some degree of aspiration and contamination of the tracheobronchial tree.

b Tracheostomy Tubes

Most tracheostomy tubes, ETTs, and cuffs are made of polyvinyl chloride, a plastic to which bacteria readily adhere. Clumps of rod-shaped and coccoid bacteria have been identified on the surface of ETTs and, by extension, tracheostomy tubes. Cultures of this material have grown a variety of gram-negative and gram-positive bacteria, including Pseudomonas aeruginosa, Proteus mirabilis, Staphylococcus aureus, and Staphylococcus epidermidis. These bacterial clumps may reach the tracheobronchial tree and lungs through detachment and aspiration or be dislodged during suction or bronchoscopy. Tracheostomy tubes that are made of polyvinyl chloride may serve as reservoirs for persistent contamination of the tracheobronchial tree.

2 Infection Sites

a Stomal Infection

Colonization of the surgical wound after tracheostomy occurs within 24 to 48 hours with primarily gram-negative organisms, including Klebsiella, P. aeruginosa, Escherichia coli, and occasionally S. aureus.^7,¹³¹ Wound edges may demonstrate mild erythema, and yellow or green secretions from the area may be copious, particularly in the first 7 to 10 days. These findings are more marked after standard open tracheostomy than PDT, probably because of the very small incision and tight tract in the latter procedure. Frequent and meticulous wound care with mechanical débridement, if necessary, is the best way to deal with this situation. Progressive cellulitis, despite aggressive local care, indicates infection, usually polymicrobial, and warrants systemic antibiotics. Rarely, necrotizing stomal infections may occur, with substantial loss of soft tissue down to and including the tracheal wall. This may create difficulties in maintaining adequate mechanical ventilation. Progression of the process may result in carotid artery exposure, with its attendant risks. Management involves replacing the tracheostomy tube with an ETT and aggressive wound débridement and cleaning with antiseptic dressings. Rarely, local flaps may be necessary to provide soft tissue coverage for vital structures.

b Tracheostomy Tubes

Colonization of the wound, along with mechanical irritation from the tube, cuff, and tube tip, means that there is always some degree of localized, reversible tracheitis, which often manifests by increased secretions. Progression of this situation may lead to loss of tracheal support, resulting in tracheal stenosis or tracheomalacia. Full-thickness loss may result in life-threatening complications such as tracheal-esophageal or tracheal-innominate fistula. Selecting appropriate tube sizes, materials, and cuffs can minimize mechanical irritation. The cuff should be inflated only when necessary.

The known bacterial colonization of polyvinyl chloride devices makes a strong argument in favor of more frequent tube changes, perhaps weekly, in ventilator-dependent, critically ill patients.

c Hospital-Acquired and Ventilator-Associated Pneumonia

Hospital-acquired pneumonia (HAP) accounts for up to 25% of all ICU infections and for more than 50% of the antibiotics prescribed.¹³² Ventilator-associated pneumonia (VAP) occurs in 9% to 27% of all intubated patients.^133,¹³⁴ In ICU patients, almost 90% of HAP episodes occur during mechanical ventilation. In mechanically ventilated patients, the incidence increases with duration of ventilation.¹³⁰ Important risk factors for HAP include exposure to invasive respiratory devices and aspiration of oropharyngeal pathogens or leakage of secretions containing bacteria around the ETT.¹³⁰

Newly developed taper-shaped cuffs and suction above the cuff systems (Mallinckrodt TaperGuard Evac tube and Portex SACETT) seem to significantly reduce microaspiration compared with the Hi-Lo cuffs, reducing the incidence of VAP. The introduction of similar improvements for tracheostomy tubes may contribute to a reduction in the incidence of VAP in long-term mechanically ventilated patients.