1 What are the different techniques for a surgical airway?

2 How is a percutaneous tracheotomy performed?

Most intensivists perform a percutaneous tracheotomy by the Ciaglia technique, which inserts a needle into the trachea under bronchoscopic guidance. A guidewire placed through the needle allows insertion of a Teflon introducer dilator followed by a single curved dilator that increases in caliber from the tip to base where it matches the dimensions of a tracheostomy tube. After stomal dilatation, a tracheostomy tube loaded onto an introducer is inserted over the guidewire. Percutaneous tracheotomy can also be performed with insertion of a balloon catheter between tracheal rings that dilates a stoma tract after balloon inflation. Also, a specialized guidewire dilating forceps (called a GWDF technique) has a groove that allows loading of a guidewire onto forceps and dilates the trachea, threads the wire, and inserts a tracheostomy tube over the wire by a Seldinger technique. In the United States the Ciaglia technique with a curved, graduated dilator is the most commonly performed percutaneous procedure for tracheotomy.

3 What are the indications for a tracheotomy?

The four indications for tracheotomy are as follows:

4 What are the relative advantages of percutaneous versus surgical tracheotomy?

Both techniques provide effective and safe access to the trachea for critically ill patients. No high-quality prospective randomized trials have provided evidence that one procedure is better than the other. However, many studies suggest that percutaneous tracheotomy has advantages of shorter procedure time, ease of performing the procedure in the intensive care unit (ICU), decreased cost by avoiding use of an operating room (OR), provision of a tighter stoma that decreases stomal bleeding and improves tube stability, and lower risk of stomal infections. Performance of the procedure in the patient’s ICU room also expedites an earlier tracheostomy by avoiding the need to schedule OR time. Some surgeons, however, perform standard surgical tracheotomies in the ICU, thereby diminishing the cost benefits of percutaneous tracheotomy by avoiding use of the OR. When a standard surgical tracheotomy is done in the ICU, the ICU room must have adequate lighting and otherwise simulate the OR environment and resources.

5 Is emergency tracheotomy the surgical procedure of choice in patients with apnea and acute upper airway obstruction when intubation fails?

No. Tracheotomy is acceptably safe when performed electively in an OR environment under controlled clinical conditions. Risks of surgical complications increase fivefold, however, when tracheotomy is applied in an emergency situation. An emergency cricothyroidotomy provides the greatest likelihood of successful airway placement with the lowest risks for complications in patients with acute upper airway obstruction who cannot undergo translaryngeal intubation. Advantages of a cricothyroidotomy in this setting derive from the superficial location of the cricothyroid membrane that allows rapid and reliable insertion of an airway.

6 Can a percutaneous tracheotomy be safely performed in a patient receiving mechanical ventilation who requires positive end-expiratory pressure (PEEP)?

Percutaneous tracheotomy can be performed successfully in patients with severe respiratory failure who require high levels of PEEP. In one reported series the procedure was performed under bronchoscopic guidance for patients with mean PEEP levels of 16.6 cm H₂O (range, 12-20 cm H₂O), and no deterioration of arterial oxygen was found at 1 and 24 hours after the procedure compared with patients with lower PEEP levels (mean, 7.6 cm H₂O; range, 5.4-9.8 cm H₂O).

7 How is a cricothyroidotomy performed?

The cricothyroid membrane is located approximately 2 to 3 cm below the thyroid notch. The membrane, which is typically 1 cm in height, lies below the vocal cords but within the subglottic larynx. For a surgical cricothyroidotomy, a scalpel is used to incise the overlying skin and stab the membrane. The resultant opening into the airway is enlarged with a spreader, allowing placement of a tracheostomy tube. For a percutaneous cricothyroidotomy, commercially available instruments designed for emergency situations allow puncture of the membrane and introduction of an airway cannula in one maneuver.

8 Why do all patients not undergo a cricothyroidotomy rather than a tracheotomy?

For long-term airway access, cricothyroidotomy has a higher incidence of delayed airway damage; therefore most intensivists limit its use to 3 to 7 days after emergency insertion. If a patient remains ventilator dependent after this time, recommendations exist to convert a patient with a cricothyroidotomy to a tracheotomy. No studies exist to support this recommendation, however, with some studies reporting more airway injury in patients who undergo conversion.

9 What are the complications of tracheotomy?

Tracheotomy complications are categorized as intraoperative, early postoperative, and late postoperative. The most common complications during each of these periods are listed in Box 15-1.

10 What is the most lethal complication of tracheotomy in the perioperative period?

Inadvertent decannulation of a tracheostomy tube during the first 1 to 5 days after its placement represents a potentially lethal clinical event. It may take several days for a tracheostomy incision to form a stomal tract that allows blind replacement of a decannulated tracheostomy tube. Before this time, attempts to reinsert a tracheostomy tube will most likely create a false tissue tract in the pretracheal space. Subsequent attempts to provide ventilation to the patient with positive pressure through a misplaced tube result in profound cervical emphysema and external compression of the trachea, leading to asphyxia.

11 Can patients with mechanical ventilation and a tracheostomy speak?

Several techniques promote speech in patients with mechanical ventilation and a tracheostomy tube in place. Patients with low to moderate minute ventilation requirements can whisper intelligibly if the tracheostomy tube cuff is deflated to allow a small cuff leak during the ventilatory inspiratory cycle. Addition of a small amount of PEEP creates a leak throughout inspiration and expiration and promotes more continuous and spontaneous speech. A speaking tracheostomy tube provides an external cannula that directs compressed gas to exit the tube below the vocal cords, allowing some patients to communicate in whispered tones. An electrolarynx placed against the neck near the laryngeal cartilage generates a vibratory tone that can be articulated with practice into intelligible speech. If patients have limited or no mechanical ventilatory requirements, a one-way valve can be placed in-line between a fenestrated tracheostomy tube with a deflated cuff and the ventilator tubing, allowing expiration through the native airway and promoting intelligible speech.

12 What is the ideal size of a tracheostomy tube for a patient?

No one size is best for all patients because tracheal caliber and clinical situations vary. Small-caliber tubes may decrease the incidence of tracheal stenosis at the stoma site because of the smaller tracheal incision required. Unfortunately, small tubes present difficulties in airway suctioning, spontaneous ventilation, and fiberoptic bronchoscopy. Furthermore, small tubes have small cuffs that may damage the tracheal mucosa because they require high intracuff pressures to overdistend to seal the airway. Overly large tubes require wide stomas and prohibit adequate cuff inflation to cushion the rigid tube from the tracheal mucosa and to effectively prevent aspiration. The best approximation of ideal size requires the surgeon to select a tube with an outer diameter two thirds the inner caliber of the patient’s trachea at the point of insertion.

13 Why is it important to monitor intracuff pressures?

Cuff pressures in excess of mucosal capillary perfusion pressures (usually 25 mm Hg) can rapidly cause mucosal ischemia and resultant tracheal stenosis. If a tracheostomy tube is underinflated (< 18 mm Hg) in a patient undergoing mechanical ventilation, the risks for aspiration and nosocomial pneumonia increase. Therefore most experts recommend maintaining cuff pressure between 18 and 25 mm Hg. Clinicians should notice the units of measurement of cuff pressures and make the appropriate conversion from centimeters of water to millimeters of mercury to allow adherence to cuff pressure standards (Cuff pressure in millimeters of mercury = [Measured cuff pressure in centimeters of water]/1.36).

14 Should tracheostomy tube cuff pressures be directly measured periodically in patients undergoing mechanical ventilation?

Frequent monitoring of cuff pressure with a pressure gauge provides the only measure to prevent tracheal injury at the cuff site. Other techniques, such as finger palpation of the external inflation bulb, minimal occlusive volume, and the tension felt by the operator on an inflating syringe, do not substitute for direct measurements of intracuff pressure.

15 What precautions should be exercised in patients with a cuffed tracheostomy tube who undergo general anesthesia?

Some volatile anesthetics, such as nitrous oxide, diffuse more rapidly into a tracheostomy tube cuff than oxygen or nitrogen can diffuse out and thereby increase intracuff pressures. During a 2-hour operation, cuff pressures may increase from 15 mm Hg to over 80 mm Hg, which can cause ischemic injury to the tracheal mucosa. Appropriate precautions include frequent monitoring of cuff pressures in the OR or inflation of the tube cuff at the outset of the surgical procedure with the anesthetic gas mixture administered to the airway. Similarly, cuff pressures should undergo frequent monitoring while patients with tracheotomies are transported by helicopter or planes between facilities because increased altitude and lower barometric pressures will also cause cuff overinflation.

16 What should the clinician consider in any patient with airway hemorrhage after the first 48 hours of insertion of a tracheostomy tube?

Bleeding within the first 48 hours of tracheotomy is usually a result of hemorrhage from the incisional wound. Any bleeding that develops more than 48 hours after surgery should suggest the possibility of a tracheoarterial fistula, which develops as a communication between the trachea and a major intrathoracic artery. The innominate artery is most commonly involved because it lies nine to 12 tracheal rings below the cricoid cartilage within reach of a tracheostomy tube. A tube cuff or tip can erode the anterior tracheal wall as a result of pressure necrosis and penetrate the artery. This life-threatening complication requires immediate evaluation by a thoracic surgeon capable of performing an emergency sternotomy for ligation of the innominate artery because massive hemorrhage often develops after an initial herald episode of mild to moderate bleeding.

17 How should you evaluate a patient who continues to have cough and shortness of breath 2 months after removal of a tracheostomy tube?

Although these symptoms often accompany underlying lung disease, they also occasionally represent the only clinical manifestations of a tracheoesophageal fistula. Patients undergoing positive-pressure mechanical ventilation may experience gastric distention or frequent belching. Recurrent aspiration of esophageal secretions may manifest as nosocomial pneumonia. A tracheoesophageal fistula related to pressure necrosis by the tube cuff or catheter tip occurs as a complication of tracheostomy in fewer than 1% of patients. Risk factors include excessive tube movement, high ventilator inflation pressures, overinflated cuffs, prolonged intubation, diabetes mellitus, and the presence of a nasogastric tube.

Suspicion of a tracheoesophageal fistula should be pursued by endoscopic evaluation by either tracheoscopy or bronchoscopy, which can establish the location and extent of the fistula.

18 Do ventilator-dependent patients wean faster from the ventilator if an early tracheotomy is performed?

No high-quality studies have definitively answered the question whether routine, early tracheotomy within the first 4 to 7 days of mechanical ventilation improves clinical outcomes in general populations of critically ill patients. These studies are difficult to design because physicians demonstrate tremendous inaccuracies during the first 4 to 7 days of mechanical ventilation in identifying which patients may undergo successful extubation within the next few days, thereby avoiding an unnecessary tracheotomy. Accumulated evidence and expert opinion, however, conclude that tracheotomy versus continued endotracheal intubation does not improve survival or even shorten hospital stay. However, tracheotomy may improve patient comfort, decrease sedation needs, and allow earlier mobilization. There is no clear evidence that early tracheotomy decreases risk for ventilator-associated pneumonia.

19 When should a tracheotomy be performed in a ventilator-dependent patient?

Because clinical studies have not determined the ideal time to perform a tracheotomy in patients who require long-term mechanical ventilation, clinicians must individualize the decision. A tracheotomy should be considered when a patient appears likely to benefit from the procedure and when a need for prolonged ventilation becomes apparent. The potential benefits of tracheotomy over prolonged translaryngeal intubation include improved comfort, enhanced ability to communicate, and greater mobility. The anticipatory approach of estimating likely duration of ventilator dependency and likelihood of benefiting from tracheotomy is preferred over the routine selection of patients for tracheotomy after an obligate duration of intubation, which has been termed calendar watching.

20 Describe the role of a fenestrated tracheostomy tube in the ICU

Newer fenestrated tracheostomy tubes with multiple small holes in their greater curvature assist speech and weaning from tracheostomy in spontaneously breathing patients without stimulating growth of granulation tissue. After removal of an inner cannula (if present) and deflation of the cuff, patients can breathe around the cuff and through the fenestrations in addition to the stoma to decrease airway resistance. Placement of a one-way valve, such as the Passy-Muir valve, on the tracheostomy tube allows patients to inhale through the tube and exhale out their native upper airways, thereby promoting speech.

Some physicians recommend placement of a fenestrated tracheostomy tube to facilitate gradual weaning toward decannulation. Others prefer to use a tracheal button, arguing that placement of a fenestrated tube interferes with spontaneous clearing of secretions through the native airway and delays decannulation.

21 What is a tracheal button?

Tracheal buttons, such as the Olympic tracheal button and the Montgomery tracheal button, assist weaning from a tracheostomy tube (Fig. 15-1). Designed as a straight, rigid, or flexible plastic or Silastic tube, tracheal buttons fit through the stoma to maintain its patency in case patients need suctioning or reinsertion of a tracheostomy tube through the tract. The button is ideal for patients with borderline ventilatory status because the distal end abuts the anterior tracheal wall and does not protrude into the airway to impede respiration or clearance of secretions by coughing.

Figure 15-1 A tracheotomy stoma button. The silicone distal flange deforms to allow placement into the trachea through the stoma tract.

22 Why do patients aspirate after removal of a tracheostomy tube?

Scarring at the stoma site may interfere with the rostrocaudal excursion of the larynx during swallowing, which is necessary for glottic closure. In addition, prolonged diversion of ventilation away from the glottis causes attenuation of the vocal cord adductor response that is important in aspiration prevention.

23 When should you suspect upper airway obstruction after decannulation of a tracheostomy tube?

Patients may have upper airway obstruction immediately after decannulation, or obstruction may develop up to 6 months later. Causes of delayed upper airway obstruction after decannulation include subglottic or tracheal stenosis and tracheomalacia. These complications may progress slowly with a gradual narrowing of the airway causing exercise-induced dyspnea, which may be ascribed to the patient’s underlying respiratory condition or recovery from critical illness. Stridor and other classic manifestations of upper airway obstruction may be later findings after the airway is narrowed more than 90%. Late presentations with sudden onset of stridor may result from acute illnesses, such as bronchitis or pneumonia that unveils the underlying airway narrowing.