Page 575 - Hall et al (2015) Principles of Critical Care-McGraw-Hill

CHAPTER 45: Airway Management 395

guidance, incurring additional expense, time delay, and need for due to chronic irritation or erosion of the trachea, including tracheo-
additional operators to provide some increase in the safety of the esophageal fistula, tracheo-innominate fistula, tracheomalacia, and
procedure. Although simultaneous bronchoscopy is advocated by tracheal stenosis.
some authorities, many more experienced operators rarely if ever use a The absence of a large epidemiologic database, the heterogeneity of
bronchoscope to facilitate the procedure. The speed with which percu- patient populations undergoing tracheostomy in the ICU, and the high
taneous tracheostomy without the use of a bronchoscope can be accom- mortality in some patient populations that undergo the procedure make
plished is impressive, making it attractive as a procedure to emergently discussion of the long-term complications of tracheostomy difficult.
70
secure the obstructed airway in institutions with readily available kits Tracheal stenosis is diagnosed in 40% to 60% of patients who have
and highly skilled operators. Morbid obesity and previous tracheostomy undergone tracheostomy, but it is unclear if this is a complication of
are frequently cited contraindications to percutaneous tracheostomy, their tracheostomy or their prior transglottic tracheal intubation. 71,72 The
but there are case series that suggest that the procedure can be per- high cuff pressures thought to be the major cause of the tissue injury
formed safely in select patients with these diagnoses, as well. 65,66 There that drives this process are more likely to be present during the early,
is no doubt that as with any other procedural skill, there is and will be acute phase of critical illness, when high airway pressures are present.
73
significant variation across practitioners and institutions, which makes On the other hand, the disruption of the tracheal cartilages caused by
rigid prescriptions about percutaneous tracheostomy inappropriate. the presence of the tracheostomy tube may lead to instability, which
■ MINITRACHEOSTOMY may in turn cause tissue injury, which may be worsened by the immune
response to both the tracheostomy tube and the purulent secretions that
Minitracheostomy is a procedure that is sometimes performed in select contaminate its tract. Given this, it is unsurprising that a majority of the
tracheal stenoses attributed to tracheostomy occur at the level of entry
critically ill patients to facilitate clearance of bronchial secretions.
67
Minitrach™ allows repeated suctioning of the trachea below the cords into the trachea.
Tracheo-innominate fistula occurs in less than 1% of patients,
without passing a tube through them at the cost of undergoing the
procedure (which is generally performed at the bedside) with its atten- typically within 1 month of undergoing insertion of a low-lying tracheo-
stomy. Either the tip of the tube or its cuff erodes through the anterior
dant complications. The procedure itself is very similar to that described
for percutaneous tracheostomy, except that it does not require significant wall of the trachea and into the vessel, causing life-threatening bleed-
ing, which requires immediate surgical repair. Significant bleeding
dilation of the track to the trachea, and it does not result in an airway.
Minitracheostomy has been demonstrated to reduce the incidence of from the fistula is often preceded by a relatively mild herald bleed.
Tracheoesophageal fistula occurs via the same mechanism, but entails
radiographic collapse, but has not otherwise been proven to improve
outcomes. 68,69 Minitracheostomy is commonly done at a few centers, erosion through the posterior wall of the trachea into the esophagus.
Tracheoesophageal fistula is frequently difficult to diagnose, as it can
rarely done at most, and never done at others. This is unlikely to change
unless studies demonstrating more dramatic benefit to the procedure present as recurrent pneumonia in a ventilated patient. Other more
obvious symptoms include cuff leak refractory to inflation, aspiration
are published. of large quantities of tube feeds in spite of an appropriately inflated
■ COMPLICATIONS OF TRACHEOSTOMY tracheostomy cuff, and gastric distention with large quantities of air.
The diagnosis of a tracheoesophageal fistula can be established with
The immediate complications of tracheostomy include hemorrhage, either barium swallow or computed tomography scan. Treatment is
malpositioning of the tracheostomy tube, and pneumothorax/pneumo- usually surgical, although a variety of stents have been employed as
mediastinum. Hemorrhage can occur as a consequence of bleeding from an alternative. 74
subcutaneous vessels, neck veins, and the thyroid gland. Most postoper-
ative bleeding is venous in origin, and it may take hours for a noticeable
hematoma to form. A hematoma in the neck can compress the trachea TEACHING AIRWAY MANAGEMENT SKILLS
or cause it to deviate, resulting in increased airway pressures, a sensa- The place to learn airway management skills is the operating room,
tion of dyspnea on the part of the patient, and hypoventilation. Airway not the ICU. Basic airway management skills, although apparently very
obstruction caused by a hematoma is best treated by decompression/ simple, in fact take a great deal of time and experience to master. These
evacuation, as all other therapies will fail to interrupt the cascade of basics are best learned in an environment in which patients will gener-
events leading to deterioration and will allow the underlying process ally have normal anatomy, circulation, and lung mechanics. Elective
to progress. procedures in the operating room present ideal opportunities to learn
Rarely, tracheostomy tubes may be placed into tissue planes in the neck the basics of mask ventilation, laryngoscopy, fiberoptic laryngoscopy,
anterior to the trachea instead of in the trachea. Monitoring end-tidal nasal intubation, and insertion of LMAs. Outpatient bronchoscopies
carbon dioxide concentrations after the tube is inserted is now routine at present excellent opportunities to learn how to adequately topically
most institutions, and will aid in the timely recognition of this problem, anesthetize the nasopharynx and oropharynx. Literature from a wide
allowing it to be quickly corrected. Tracheal positioning of the trache- variety of fields supports the contention that most practitioners tasked
ostomy tube can also be verified with successful passage of a suction with managing the airway are either inadequately trained, or will
catheter through the appliance, auscultation, or fiberoptic bronchoscopy. predictably benefit from more training. 75,76 Once the basics of airway
Pneumothorax and pneumomediastinum are consequences of inva- management have been mastered in the elective setting, they can be
sion of these tissue planes, which can extend superiorly into the neck in applied to airway management in the ICU under adequate supervi-
some patients (particularly those with chronic obstructive pulmonary sion. Attempts to teach the basics of airway management at the bedside
disease or on high amounts of PEEP). These complications are more in the ICU should be discouraged, as critically ill patients do not
likely to occur in situations in which the anatomy is difficult, such as tolerate the high rates of failure that typically occur as practi tioners
patients with morbid obesity, previous neck surgery, or goiter. These learn these skills. Participating in airway management workshops
complications are usually recognized on the routine chest radiograph and the practice of various airway management techniques in models
taken postoperatively in these patients to confirm adequate positioning and simulators is extremely valuable, especially for procedures such
of the new tracheostomy tube. as fiberoptic bronchoscopy, which requires hours of practice to attain
■ LONG-TERM COMPLICATIONS OF TRACHEOSTOMY facility manipulating the bronchoscope. The wide variety of issues that
skillful practitioners must take into account at the bedside or consider
Tracheostomy tubes are frequently left in patients for months and occa- as they undertake the airway management of ICU patients are given
sionally years. This situation puts the patient at risk of complications in Table 45-9.

section04.indd 395 1/23/2015 2:18:56 PM