Indications for percutaneous dilational tracheotomy (PDT) are similar to those for open tracheotomy (OT) and include providing a portal for pulmonary toilet in debilitated patients or patients with neuromuscular disease, and providing a means for prolonged ventilatory support. Similar to OT, PDT should be considered in patients requiring mechanical ventilation 7 to 10 days following initial intubation. If prolonged intubation is expected based on patient circumstances (high spinal cord or traumatic brain injury), earlier tracheotomy may be considered.
Advantages of PDT over a prolonged translaryngeal intubation include a reduced risk of direct endolaryngeal injury, decreased risk of ventilator-associated pneumonia (VAP), more effective pulmonary toilet, increased airway security and ease in weaning from mechanical ventilation, improved patient comfort with decreased requirements for sedation, and earlier discharge from the intensive care unit (ICU). In suitable patients, the major advantage of PDT to OT is that it is performed as a bedside procedure, obviating the need for operating room time and patient transport, as well as being significantly more cost effective.
When evaluating a patient for PDT, a thorough history and physical examination will identify anatomic contraindications, including previous difficult tracheal intubation, morbid obesity, obscure cervical anatomy, goiter, short thick neck, previous neck surgery (especially tracheotomy), cervical infection, facial or cervical trauma/fractures, halo traction, or known presence of subglottic stenosis. Physiologic contraindications to PDT include hemodynamic instability, requirement of FiO2 > 0.60, a positive end-expiratory pressure (PEEP) > 10 cm H2O, or uncontrolled coagulopathy. Cervical deformity, previous radiation therapy, edema, or tumor can also make tracheal cannulation difficult and increase the risk of morbidity. The need for emergency control of the airway is an absolute contraindication to PDT.
Complications of PDT include injury to posterior tracheal wall resulting in a tracheoesophageal fistula, injury to cupula of lung with pneumothorax, tracheal ring rupture, recurrent laryngeal nerve injury, paratracheal insertion, tube dislodgement with loss of airway, stomal hemorrhage, peristomal cellulitis, subglottic or tracheal stenosis, or a tracheoinnominate fistula. A guidewire placed too deep in the trachea during the procedure can potentially cause bronchoconstriction or lung injury.
Several components are required for PDT placement, and these include bronchoscope, medications, tracheotomy insertion kit, and tracheotomy tube. Kits are available for either the single or the serial dilator technique, and either a standard or a percutaneous tracheotomy tube may be used. The tube cuff must be checked for leaks and then be well lubricated prior to placement. We recommend that the operator develop a materials checklist to facilitate gathering of the critical components prior to the procedure.
A three-drug regimen including sedative, analgesic, and nondepolarizing muscle relaxant agents facilitates placement. It is important to maintain immobility during insertion of the introducer needle, guidewire, dilators, and tracheotomy tube to prevent inadvertent puncture of the posterior tracheal wall. Direct manipulation of the trachea (particularly during dilation) is cough provoking, thus the recommendation for paralytics.
Positioning is aided with a shoulder roll to allow maximal extension of the neck during the procedure. Neck extension elevates the trachea out of the mediastinum and displaces the chin to allow greater access to the anterior neck. The palpable anatomic landmarks are shown in Figure 1. The exposed neck can then be prepped with a standard surgical scrub and sterile drapes applied.
The procedure requires two operators: one performing the tracheotomy and the second providing tracheal visualization with flexible fiberoptic bronchoscopy. Identification and transillumination of the area between the second to fourth tracheal rings with visual confirmation of proper tracheotomy tube positioning improves success in patients with poorly palpable surface anatomy. A respiratory therapist maintains the endotracheal tube (ETT) position and ventilation with 100% oxygen. After all equipment is gathered, the correct level of placement of the ETT being used for control of ventilation is verified by passing a fiberoptic bronchoscope into the trachea by way of a special anesthesia adapter (Figure 2A). The skin is prepped with an antiseptic, and a sterile draping is done.
The tracheotomy is performed between the second and fourth tracheal rings. Placing the tracheotomy tube above this level may result in injury to the first ring or cricoid cartilage, which increases the risk of subglottic stenosis or bleeding from the thyroid isthmus. Placing it too low can predispose to tracheoinnominate fistula. A point midway between the cricoid cartilage and the sternal notch is palpated and marked. Local anesthesia is infiltrated in the skin and subcutaneous tissues, as well as into the trachea (Figure 3). A vertical skin incision is made in the midline from the level of the cricoid cartilage and extending 1.0 to 1.5 cm downward.
The second or third tracheal interspace is visualized in preparation for the tracheotomy.
The ETT should be withdrawn to 1 cm above the anticipated needle insertion site under bronchoscopic or transillumination guidance. In average-sized adults, the tube can be withdrawn to about the 17-cm mark at the teeth. The bronchoscope can show indentation of the trachea with palpation, locating the tracheotomy site. A 17-gauge sheathed introducer needle is then advanced in the midline, angling posterior and caudad (Figure 4). Aspiration with an attached syringe containing a small amount of water will indicate when the tracheal wall has been punctured. Puncture of the trachea is confirmed bronchoscopically to ensure midline needle placement (Figure 4). The stylet or needle is removed leaving the outer cannula in the trachea. The “J”-tip guidewire is advanced through the cannula into the trachea toward the carina (Figure 5). After cannula removal, a short 14-French mini-dilator is advanced over the guidewire using a slight twisting motion and then removed (Figure 6).