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408 PART 4: Pulmonary Disorders

this phenomenon varies widely, ranging from as low as 3% to as high as
TABLE 47-1 Upper Airway Problems Related to Endotracheal Intubation
30%, although most patients with postextubation stridor do not require
Related to Insertion reintubation. Women, patients with relatively large tubes and/or
17
Epistaxis (with nasotracheal intubation) small tracheas, and patients with cuff leak volumes <110 mL are at
18
Tooth avulsion and aspiration increased risk. Analyses of multiple studies of the use of corticosteroids
for the prevention of complications from laryngeal edema indicate that
Hypopharyngeal trauma single-dose regimens are ineffective for this purpose, while multiple-
Laryngospasm (either from airway manipulation or medications) dose regimens administered to high-risk patients 12 to 24 hours prior
Laryngeal or tracheal trauma or tear to extubation appear to be effective and well tolerated. 17,18 Based upon
the available evidence, it is reasonable to administer a short course of
Vocal cord paralysis and/or arytenoid dislocation
parenteral steroids beginning 12 to 24 hours prior to planned extubation
Related to Intubation in high-risk patients. Patients with a diagnosis of postextubation stridor
Endotracheal tube obstruction from secretions or kinking are typically treated with various combinations of parenteral steroids,
nebulized racemic epinephrine, and helium-oxygen mixtures, although
Vocal cord injury: edema, ulceration, granuloma, and paralysis possible
firm evidence to support these approaches are lacking.
Laryngomalacia from ischemic cuff injury
Other Traumatic Injuries Aspirated foreign bodies lodge in the upper airway
Subglottic stenosis much less commonly in adults than in children. Still, asphyxiation may
19
Tracheal stenosis follow foreign body aspiration in adults, while large objects aspirated
into the esophagus can occasionally obstruct the upper airway. Risk
Related to Extubation
factors in adults include diminished level of consciousness; impaired
Excess secretions swallowing mechanism or diminished upper airway sensation as a result
Residual sedation of neuromuscular disorder, prior cerebrovascular accident, or advanced
Laryngospasm age; and inability to chew food properly because of poor dentition. Food
particles and medical or dental appliances are most frequently aspirated.
Unmasking of coexisting laryngeal edema or other upper airway disorder Symptoms include cough and dyspnea, and stridor may be present. Chest
radiography or lateral films of the neck may reveal the diagnosis. In the
case of impending respiratory arrest, the Heimlich maneuver may be life-
Long-term endotracheal intubation may cause a variety of injuries to saving. Otherwise, the patient should undergo endoscopy in most cases
the upper airway. Fortunately, current endotracheal tube cuffs have a with a rigid endoscope. Flexible fiberoptic endoscopy is generally inad-
higher volume and lower pressure than were used a number of years ago, visable for foreign body removal because the airway cannot be protected
decreasing problems related to long-term intubation. Whether or not an if the object lodges in the glottis during removal; however, experienced
individual patient will develop subglottic or tracheal stenosis is difficult to operators may elect to attempt removal in carefully selected patients.
predict. While duration of intubation has been shown in some studies Upper airway injury may result from inhalation of toxic chemicals, or
to be correlated with laryngeal or tracheal stenosis, the relationship is more commonly from thermal injury. Upper airway burn injury should
not strong. Similarly, while increased tube caliber, frequency of inser- be suspected whenever a patient has survived a fire or explosion in an
tion, the severity of respiratory failure, female gender, and the presence enclosed space, and when chemicals or plastics have burned. Physical
of diabetes or immunocompromise have all been suggested as exac- examination findings that suggest the presence of upper airway injury
erbating factors, the data on this topic are inconsistent. As mentioned include the presence of burns or soot on the face, singed nasal hairs,
previously, the possibility of subglottic or tracheal stenosis should be erythema of the oropharynx, and hoarse voice. Sometimes the external
considered when encountering breathless patients who have undergone signs are relatively mild despite significant inhalation injury. Thus any
long-term intubation previously. In such cases, the diagnosis of UAO patient suspected of incurring inhalation injury should undergo fiber-
may easily be overlooked. Voice change and stridor are clues to the diag- optic laryngoscopy. Affected patients may experience life-threatening
nosis. CT of the upper airway with three-dimensional reconstruction UAO from airway edema and mucosal sloughing anytime from initial
can be very useful in such cases, if patient stability permits. presentation to 24 hours later. In addition, upper airway edema may be
Obstruction of the endotracheal tube from secretions may be unrec- exacerbated by the considerable amount of fluids required to resuscitate
ognized until it progresses to a point at which ventilation becomes patients with extensive burns. When the airway needs to be secured,
20
impossible. More subtle presentations may delay liberation from endotracheal intubation is preferred over tracheostomy because of the
mechanical ventilation by causing the patient to perform poorly during higher incidence of tracheal stenosis associated with the latter therapy
spontaneous breathing trials. Interestingly, luminal narrowing of the when performed in burn patients. Because corticosteroids increase the
endotracheal tube cannot be predicted based on its duration of use. incidence of infectious complications and may increase mortality when
16
Theoretically, tube obstruction may be prevented through frequent administered to burn patients, we do not recommend their use here.
suctioning and adequate humidification, particularly when copious and Traumatic neck injury may directly injure the larynx. Such an injury
viscous secretions are present. The development of obstructed respira- should be suspected whenever there are ecchymoses or tenderness over
tory system mechanics—a high peak to plateau airway pressure gradi- the thyroid or cricoid cartilages. In addition to pain, patients may have
ent—in a patient without a history of obstructive lung disease, or in the stridor, hoarseness, and hemoptysis. Cervical spine injury should be
absence of wheezing, suggests the diagnosis. While difficulty passing excluded, while endotracheal intubation must be done with care to avoid
a suction catheter is highly suggestive, we have removed endotracheal exacerbating any existing injury. Stabilization of the neck and avoidance
tubes that are nearly completely occluded through which a suction cath- of neck extension during airway manipulation are mandatory. In a crisis,
eter was able to be passed. If time permits, bronchoscopic examination tracheostomy may be necessary to establish an airway. The evaluation
quickly establishes the diagnosis. Chapter 49 outlines the approach to and treatment of laryngeal injury is beyond the scope of this review.
high-peak airway pressures in further detail; here, we stress that prompt There are a number of iatrogenic causes of UAO. A hematoma in
removal of the endotracheal tube, with manual mask ventilation of the the neck may cause UAO through direct compression, as may rarely
patient while awaiting reintubation, can be lifesaving. occur following surgery. Inadvertent carotid artery puncture during
Postextubation stridor from laryngeal edema complicates the course central line placement may cause a rapidly expanding hematoma with
of a substantial minority of critically ill patients, despite the use of low- airway compromise, particularly if the patient has a bleeding diathesis.
pressure, high-volume endotracheal tubes. The reported incidence of Recurrent laryngeal nerve injury may occur during neck dissection or

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