Complications of Tracheotomy
Tracheotomy has a long and colorful history. The first reference to the procedure can be found in the sacred book of Hindu medicine, the Rig Veda, dated to ~ 2000 bc. Alexander the Great is reported to have performed a tracheotomy in the fourth century bc when he “punctured the trachea of a soldier with the point of his sword after he saw a man choking from a bone lodged in his throat”.1 For centuries, however, it would remain a marginal procedure, referred to as “the scandal of surgery” because of the associated high morbidity and mortality. The work of Armand Trousseau in 1834 and later Chevalier Jackson in 1909 demonstrated that by attention to technical detail and attentive postoperative care, the mortality of the procedure could be reduced to less than 2%. Jackson emphasized the importance of a long incision, avoidance of the cricoid cartilage, routine division of the thyroid isthmus, slow and careful surgery, use of a proper cannula, and meticulous postoperative care.
Chevalier Jackson′s description of the “standard open tracheotomy”, continues to be the standard against which all others are compared. This procedure can be performed in the operating room, at the bedside in the intensive care unit (ICU), or as an emergency on the ward as required. The most significant modification to tracheotomy was the introduction of an endoscopic percutaneous technique designed specifically for use at the bedside in intubated adult ICU patients.
Indications for Tracheotomy
The primary objective of a tracheotomy is to secure an artificial airway. Over the years, the indications for tracheotomy have continued to change in parallel with the evolution of medicine. Current major indications for tracheotomy include:
Relief of upper airway obstruction (both acute and chronic)
Providing a means for assisted mechanical ventilation
Facilitating tracheobronchial toilet.
Currently over half of modern-day tracheotomies are performed on critically ill patients requiring prolonged mechanical ventilation.2
The standard open surgical tracheotomy is usually performed in the controlled setting of the operating room. Guiding surgical principles involve the following: (1) placement of the incision one to two fingerbreadths below the cricoid; (2) displacing or ligating the anterior jugular veins, as required; (3) displacing or dividing the thyroid isthmus to provide access to the anterior tracheal wall; (4) entering the trachea between the second and third, or third and fourth, tracheal rings; (5) placement of tracheal retention sutures to facilitate reinsertion of the tracheostomy tube in case of early dislodgement; and (6) meticulous postoperative wound care and suctioning. Although the technique is usually performed in the operating room, it may also be performed at the bedside in intubated ICU patients, or as an emergency life-saving procedure just about anywhere in the clinical setting.
Critically ill intubated ICU patients represent a special subset of the population by virtue of their multisystem disease and the complexity of the care they require. Tracheotomy is a frequently performed procedure in these patients, and, not surprisingly, is associated with a higher risk.2 As such, special consideration is required in terms of indications, technique, and care. Moving these critically ill patients with their monitors requires additional personnel and carries several different risks, including accidental extubation and vital sign changes requiring pharmacologic intervention.3,4 These factors served as the impetus for the development of a simple, yet safe bedside technique.
Seldinger′s description5 in 1953 of catheter replacement of the needle in percutaneous arteriography over a guidewire served as a basis for the development of a bedside percutaneous dilatational tracheotomy (PDT) technique. The “blind aspect” of the procedure was subsequently addressed by the addition of endoscopic guidance, first reported in 1990 in 61 patients by Marelli et al.6 The technique is based on progressive dilatation of an initial tracheal puncture. Kost′s series of 500 cases published in 2005,7 demonstrated that, with bronchoscopic visualization and attention to technical detail, endoscopic PDT is a safe, cost-effective alternative to surgical tracheotomy in the operating theater for adult, intubated ICU patients.
The vast majority of complications are preventable through:—Careful preoperative planning—Attention to technical detail during the procedure—Meticulous postoperative care.
Traditionally, tracheotomy has been performed in the operating room, which is fully equipped with adequate lighting, suction, and assistance. Patients with an unprotected airway as well as those from the emergency room are best transferred to the controlled, monitored setting of the operating room whenever possible. Adult, intubated patients from the ICU may undergo tracheotomy (open or percutaneous) safely either at the bedside8–10 or in the operating room11,12 with comparable complication rates.
It is imperative to examine the patient preoperatively paying particular attention to the neck to anticipate and plan for special situations. The presence of a midline neck mass or high innominate artery may require modification of the level of incision or entry into the trachea, or both. Patients who have undergone previous surgery or radiotherapy to the neck are likely to have scarred, fibrotic, indurated tissue, which precludes the ability to identify any landmarks. In these cases, slow, careful, midline dissection prevents injury to adjacent structures such as the carotid artery and allows identification of the airway. Patients with severe cervical osteoarthritis, kyphoscoliosis, or other conditions, in whom the neck cannot be hyperextended; present a formidable surgical challenge.
It must be stressed that PDT is suitable only in adult intubated patients. This patient population accounts for almost two-thirds of all tracheotomies performed today.
The inability to palpate the cricoid cartilage above the sternal notch
The presence of a midline neck mass or large thyroid gland
A high innominate artery
Patients with an unprotected airway, or patients with acute airway compromise
Children, because of the different airway anatomy as well as the technical difficulties of maintaining adequate ventilation with a bronchoscope within a small endotracheal tube13
Patients requiring a positive end-expiratory pressure ≥ 15 cmH2O as they are at high risk for complications such as subcutaneous emphysema and pneumothorax.
Patients with the above conditions should undergo standard surgical tracheotomy (ST) in the operating room. Patients having had a previous tracheotomy may undergo PDT safely if they have no other contraindications.7 Obese patients may also undergo PDT provided a proximally extended tracheostomy tube is used to reduce the risk of accidental decannulation.
Whether an ST or an endoscopic PDT is performed, every effort should be made to optimize the patient′s comorbidities before surgery. Preoperative testing is minimal and includes a recent chest radiograph as well as serum determination of hemoglobin, prothrombin time, partial thromboplastin time, International Normalized Ratio, and platelets. Coagulopathies should be corrected to an International Normalized Ratio < 1.5, with > 50,000 functioning platelets. The use of aspirin or other nonsteroidal anti-inflammatory medications, and clopidogrel bisulfate (Plavix, Bristol-Myers Squibb Co., New York, NY, USA) should be discontinued for 7 days preoperatively, if at all possible. Aspirin and clopidogrel bisulfate are commonly used together in patients who have had cardiac stent placement, strokes or myocardial infarctions. Patients taking both drugs have a higher incidence of perioperative bleeding and at least one of these agents should be stopped before tracheotomy. Patients on warfarin should stop the drug 5 days before surgery or should receive infusions of fresh-frozen plasma or intravenous or oral vitamin K for rapid reversal of anticoagulation. A cross-match should be obtained if the hemoglobin is < 100 g/dL.
The anesthesia team plays an important role during the procedure: monitoring the airway and vital signs, and keeping the patient stable. Patients suffering from chronic respiratory insufficiency and high CO2 levels may lose their respiratory drive or even develop pulmonary edema following establishment of an airway with tracheotomy. Support in the form of assisted ventilation and appropriate pharmacologic intervention is usually sufficient, although cardiopulmonary resuscitation may be necessary in severe cases.
The choice of tracheostomy tube is important. The purpose of a tracheostomy tube is to:
Provide an airway
Allow for mechanical positive-pressure ventilation
Reduce the risk of aspiration
Facilitate suctioning the tracheobronchial tree.14
Cuffed tubes should have a low-pressure, high-volume cuff to reduce the possibility of tracheal stenosis. Tubes with an inner cannula are preferable because the inner cannula can be quickly removed in the event of a mucus plug, leaving the open outer cannula in situ and the airway protected.
Obese patients with thick pretracheal soft tissues are likely to require extended-length tubes to decrease the risk of accidental decannulation or tube displacement.7 It has been shown that pretracheal soft tissue thickness can be reliably predicted within 4 mm in obese patients as a function of neck and arm circumference.15 It can be seen that a patient with a neck circumference of 55 cm and an arm circumference of 50 cm would have a pretracheal soft tissue thickness of 3 cm. A proximally extended tracheostomy tube would be required in this patient because “standard” tubes have a much shorter proximal length ( Fig. 18.1 ). It should be noted that tracheostomy tubes with either proximal or distal extensions are available. Tubes with adjustable flanges and those made of softer, thermolabile materials for anatomically difficult necks or tracheas are also available. Choosing the correct tracheostomy tube preoperatively is helpful in decreasing postoperative complications such as accidental decannulation, skin maceration/infection, granulation tissue, and tracheitis, all of which may be related to ill-fitting tubes.
Patients with altered anatomy require special consideration. Patients with a history of radiotherapy with or without chemotherapy for head and neck malignancies often have stiff, indurated soft tissue and limited neck extension. Landmarks are predictably difficult to palpate or not palpable at all. Patients with kyphoscoliosis may also have poorly identifiable landmarks. These situations may present formidable surgical challenges. Preoperative localization of the airway with ultrasound is sometimes helpful. In all cases, careful midline dissection, frequent palpation of the laryngotracheal framework during the procedure, and identification of the airway with a needle, are all measures that help to reduce the probability of injury to adjacent structures and postoperative complications.
For tracheotomies performed in the ICU, a fully equipped intubation cart should be readily available in the event of accidental extubation during the procedure.
As with all other minimally invasive techniques, there is a learning curve for endoscopic PDT. Familiarity with open surgical tracheotomy does not confer expertise in PDT and appropriate training should be obtained before using the technique. Careful selection of patients with anatomically favorable necks for the first 30 to 40 patients allows the surgeon to gain experience and reduce the likelihood of complications.
Attention to Technical Detail
For both ST and PDT, careful attention to technical details will help to minimize the risk of complications. Guiding surgical principles involve the following:
Placement of the incision one to two fingerbreadths below the cricoid
Displacing or ligating the anterior jugular veins, as required
Displacing or dividing the thyroid isthmus to provide access to the anterior tracheal wall
Entering the trachea between the second and third, or third and fourth tracheal rings
Placement of tracheal retention sutures to facilitate reinsertion of the tracheostomy tube in case of early dislodgement
Meticulous postoperative wound care and suctioning.
Technical details that are particular to endoscopic percutaneous tracheotomy include the following:
The cricoid cartilage should be identified. Inability to palpate this important landmark constitutes an absolute contraindication to percutaneous tracheotomy.
The procedure should only be performed under continuous endoscopic visualization. Complication rates increased two-fold when bronchoscopy is not used.7 The bronchoscope ensures proper placement of the initial tracheal puncture, and allows visualization of the posterior tracheal wall.
Force should never be used during dilatation or tracheostomy tube insertion. Resistance almost always indicates a problem, which must be identified and corrected before proceeding.
Because of the tight tract, tracheostomy tube changes should be avoided for the first 5 to 7 days postoperatively. Accidental decannulation during this time should be addressed by reintubating the patient. Attempts to reinsert the tracheostomy tube are likely to result in creation of a false passage.
In obese patients, a proximally extended tracheostomy tube should be placed.
Postoperative care of the tracheostomy site is facilitated if there is the opportunity for preoperative teaching. Knowing what to expect helps both children and adults adjust to this new way of breathing. Evidence indicates that patients undergoing tracheotomy experience a reduced quality of life.16 Appropriate teaching, family counseling and highly skilled nursing care are all key factors in reducing anxiety and ensuring a smooth postoperative course. A multidisciplinary tracheotomy team involving a physician, nurse, respiratory therapist, and speech-language pathologist is ideal in coordinating and delivering the complex care that tracheotomy patients require.17 The team assists with wound care, tracheostomy tube changes, deglutition, communication, decannulation, and teaching of the patient and caregivers. The presence of a multidisciplinary tracheotomy team produces measurable results in terms of decreased postoperative morbidity: the frequency of tube obstruction decreases, the use of speaking valves increases, and patients are decannulated more rapidly.18
In the initial postoperative period, patients are positioned with the head of the bed elevated 30° to 45° to maximize the ease of coughing and deep breathing, to facilitate suctioning, and to minimize discomfort. Vital signs require frequent monitoring because changes in blood pressure, respiratory rate, or pulse rate may indicate a new or ongoing respiratory problem, or that the tube may be plugged or have come out of the trachea. Agitation, anxiety, and restlessness may all indicate hypoxia and should not be dismissed or treated with anxiolytics.
Tracheal suctioning plays a key role in maintaining pulmonary toilet and patency of the tracheostomy tube. Initially, this should be done as aseptically as possible and may be necessary as often as three or four times daily. Patients on mechanical ventilation are at risk for hypoxia and cardiac arrhythmias during suctioning because oxygen-rich air is suctioned and catheters may be too large. This can be prevented by ventilating the patient on 100% oxygen for at least five breaths before and after suctioning, and limiting suctioning to ≤ 12 seconds with a small catheter. As an alternative to this open technique, a closed, multiple-use suction catheter contained within a sheath may be used.19 Similarly, to avoid mucus plugging of the tube, the inner cannula must be removed frequently for cleaning. Currently, inner cannulas are either disposable or reusable.
Humidification is extremely important in facilitating mucociliary transport of secretions and preventing serious complications such as crusting, accumulation of secretions, and eventual obstruction of the airway. Humidification is usually performed by a tracheal mask. T-tubes are best avoided because of the torque exerted on the tube, which traumatizes the tissue every time the patient moves.
The importance of meticulous local wound care cannot be overemphasized. The tracheostomy site should be cleaned as often as necessary (three or four times daily) with normal saline or hydrogen peroxide to prevent skin breakdown and infection. The neck tapes holding the tracheostomy tube in place should be changed, as necessary, when soiled. The skin under the tracheostomy neck plate should be kept dry with a thin nonadherent dressing such as Telfa (Covidien, Mansfield, MA, USA) to prevent skin maceration.
Following open surgical tracheotomy, it takes at least 48 to 72 hours for a tract to form, and therefore tracheostomy tube changes should be avoided during this period. Accidental decannulation in the early postoperative period can be very dangerous (even with stay sutures) because of the almost immediate soft tissue collapse, which greatly increases the possibility of tube misplacement in a false passage when reinsertion is attempted. In these cases, reintubation is the safest option. Tracheostomy tube change in the early postoperative period should be avoided unless there is a compelling reason, such as cuff failure, to do so. Should such a situation arise, skill and preparation are necessary for safe tube replacement. These requirements include:
Optimal patient positioning
Two tracheostomy tubes: ideal and smaller size
Tracheostomy tube exchanger.
The use of a tracheostomy tube exchanger may be a very helpful adjunct for early tracheostomy tube changes. The exchanger is a long semiflexible tube with a central lumen through which ventilation is possible. The exchanger is inserted into the tracheostomy tube, which is then removed and replaced with the new tube. The exchanger “guides” the new tracheostomy tube into the trachea. If for any reason the new tracheostomy tube is difficult to replace, ventilation may be temporarily continued through the exchanger.
The PDT technique is primarily dilatational with minimal tissue dissection resulting in a tight tract and a very snug fit of the tracheostomy tube. The technique does not allow for easy 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 to 7 days of the procedure while the tract is still relatively immature. Attempts at forcefully replacing the tracheostomy tube in an emergent situation could result in bleeding, the creation of a false passage, pneumomediastinum, hypoxia, and even death.
Patients who do not require a cuffed tube may benefit from a Passy–Muir or speaking valve in the postoperative period. This one-way valve allows inspiration through the tracheostomy tube and closes on expiration, deflecting air through the vocal folds and permitting phonation. It has also been noted that these valves improve swallowing mechanics by restoring subglottic pressure, thereby facilitating deglutition. Contraindications for use of a speaking valve include: cuffed tracheostomy tube, upper airway obstruction, bilateral vocal fold paralysis, severe tracheal stenosis, copious inspissated secretions, and cognitive dysfunction.
Decannulation in adults can be safely accomplished by following a few simple steps. Indirect or flexible endoscopy should be used in both children and adults to ensure that the upper airway is adequate and the larynx is competent. Granulomas projecting into the stoma should be removed. The tube may then be downsized and plugged during waking hours. The period of plugging allows for adequate evaluation of airway adequacy. It also affords time for laryngeal adductor reflexes to be activated. The patient must be instructed to remove the plug in the event of dyspnea or shortness of breath. If the plug is not tolerated further, the nature of the obstruction must be investigated before further attempts at decannulation. If the patient tolerates the plug for 24 hours, then the cannula can be removed and the stoma can be covered with a light dressing and occlusive tape, which is changed as necessary. In the vast majority of cases, the stoma will close by secondary intention within a few days. The resultant scar from a transverse incision is cosmetically superior to that from a vertical incision.