Plate 186

Tracheotomy is performed for two groups of patients. The first group comprises those with an obstruction of the airway at or above the level of the larynx. Such obstruction may result acutely from laryngeal tumors, edema, fracture, foreign bodies, burns about the oropharynx, or severe throat and neck infections.

The second group consists of patients with chronic or long-term respiratory problems. Inability to cough out tracheobronchial secretions in paralyzed or weakened patients may be an indication for tracheotomy, which allows frequent and easy endotracheal suctioning. This group of patients includes those with prolonged unconsciousness after drug intoxication, head injury, or brain surgery and those with bulbar or thoracic paralysis, as in poliomyelitis. To this group are added patients with general debility, especially in the presence of pulmonary infection or abdominal distention, where a temporary course of respiratory support with an endotracheal tube and mechanical ventilator for 10 to 14 days must be converted into a longer course of pulmonary assistance. In these patients inability to maintain an adequate gas exchange or oxygen or carbon dioxide may dictate conversion of the endotracheal tube to a tracheotomy tube. Frequently, checks of arterial blood gases will reveal hypoxemia or hypercarbia, while simple measurements of vital capacity and negative inspiratory force will detect insufficient respiratory muscular effort. These tests are important in the decision to continue tracheal intubation with ventilator assistance. Other candidates for tracheotomy may include patients undergoing major operative or radical resections of the mouth, jaw, or larynx, where this procedure often is done as a precautionary measure. Antibiotics may be indicated.

Because the patient is usually in respiratory difficulty, preoperative preparation is generally not possible.

In cooperative patients, in both elective and emergency situations, local infiltration anesthesia is preferred. In patients who are comatose or are choking, no anesthesia may be necessary or possible. Because it helps to ensure a good airway during tracheotomy, endotracheal intubation is especially useful in patients whose laryngeal airway is very poor and who may obstruct at any moment. It is also an aid in palpating the small, soft trachea of infants.

A sandbag or folded sheet under the shoulders helps extend the neck (Figure 1), as does lowering the head rest of the operating table. The chin is positioned carefully in the midline.

In emergency tracheotomy, sterile preparation is either greatly abbreviated or omitted entirely. In routine tracheotomy, a sterile field is prepared in the usual manner.

Incision and Exposure

Emergency tracheotomy is done when there is no time to prepare for a routine tracheotomy. There may be no sterile surgical instruments available and no assistants.

An emergency airway is made by a transverse cut or stab through the cricothyroid membrane. Here the airway is immediately subcutaneous, yet the level is still under the vocal cords (Figure 2). The wound is held open by twisting the handle of the knife blade in the wound. Later, with the airway ensured, the patient is removed to the operating room and a routine tracheotomy is done.

Incision and Exposure

A vertical incision is made in the midline of the neck from the middle of the thyroid cartilage to just above the suprasternal notch (Figure 3). Alternatively, a transverse incision may be made at roughly the midpoint between the notch and the thyroid cartilage. The skin, subcutaneous tissues, and strap muscles are retracted laterally to expose the thyroid isthmus (Figures 4 and 5). The isthmus may be either divided and ligated or retracted upward after the pretracheal fascia is cut. Usually, upward retraction is the better method.

After the cricoid cartilage is identified (Figure 6), the trachea is opened vertically through its third and fourth rings (Figures 7 and 8). In order to facilitate insertion of the tracheotomy tube, either a cruciate incision is made or a very narrow segment of one ring may be removed (Figure 9). The transverse incision, preferred by some surgeons for cosmetic reasons, is more time-consuming. The difference in the final cosmetic result is negligible, since it is the tube and not the incision that causes scarring.

Details of Procedure

A tracheal hook is used to pull up the trachea and steady it for incision (Figure 9). Great care must be taken not to cut through the trachea too deeply, since the posterior wall of the trachea is also the anterior wall of the esophagus.

After the trachea has been incised, a previously selected tracheotomy tube is inserted. A No. 6 tube is ordinarily suitable for an adult male and a No. 5 or 6 tube for an adult female. Correspondingly smaller tubes are used in children and infants. The trachea of a newborn will accept only a No. 00 or 0 tube. The assistant must be careful to keep the tube in the trachea by holding one finger on the flange; otherwise the patient may cough it out. Plastic endotracheal tubes with an inflatable cuff usually of the size similar to oral intubation are used.

Closure

Closure should be loose to prevent subcutaneous emphysema. Only skin sutures are used. Ties hold the tube in place (Figure 10). A dressing is made by cutting a surgical gauze and pulling the gauze under the flange of the tube.

Postoperative Care

Special and frequent attention is very desirable in the first few postoperative days. The inner tube must be cleaned every hour or two; otherwise it may block off with accumulated secretions. After a tract has formed, usually in 2 or 3 days, the outer tube may be removed, cleaned, and replaced. Even then, however, the tube should be replaced rapidly, since the stoma constricts sufficiently in only 15 or 20 minutes to make replacement difficult. An obturator is provided with each tracheotomy tube to make insertion of the outer tube easier. There must always be a duplicate tracheal tube at the patient's bedside.

Suctioning of the trachea is done as needed. In the alert patient who can cough, suctioning may not be needed at all; but in the comatose patient suctioning may be required every 15 minutes. It is essential that moisture be added to the air, since the nasal chambers are bypassed and the usual means by which the body moistens the air are lost. This can be accomplished by the use of aerosol bubblers or ultrasonic nebulizers.

Blood gases and blood pH should be monitored frequently until stable and satisfactory levels have been attained.