Module 3
Complications of Managing the Airway
Complications with Supraglottic Devices
MASK VENTILATION
The maximum risk of airway problems presents during the ‘cannot intubate, cannot ventilate’
situation.2,3
Difficult mask ventilation is an underestimated aspect of the
difficult airway. The ability to ventilate and oxygenate the
patient sufficiently using a mask is essential. Face masks
should be completely free of residual cleansing agents, as these
can cause serious mucosal, skin or eye injury (conjunctivitis,
burning, irritation) and tongue swelling (allergic glossitis).
While applying a mask to a patient’s face, soft tissue damage may occur if the tissue is subjected to
excessive pressure. Care must be taken to avoid contact with the
eyes to prevent corneal abrasions, retinal artery occlusions, or
blindness. Excessive pressure on the mandible may damage the
mandibular branch of the facial nerve, resulting in transient
facial nerve paralysis. Pressure on the mental nerves has been
implicated in causing lower-lip numbness. Oropharyngeal airways
must be gently inserted into the mouth to avoid injury (broken
teeth or mucosal tears). Improper placement may worsen airway
obstruction by forcing the tongue backward. Equal care
should be given to the placement of nasopharyngeal airways to
avoid epistaxis.
During the course of induction, the lifting pressure applied to the angle of the mandible is
sometimes sufficient to subluxate the temporomandibular joint.
Patients may experience persistent pain or bruising at these
points, and may even have chronic dislocation of the jaw which
may cause severe discomfort.
Positive airway pressure can force air into the stomach instead of the trachea. Gastric
distention may occur, causing more difficult ventilation and an
increased propensity for regurgitation. For these reasons,
mask ventilation should not be performed in non-fasted or
morbidly obese patients or patients with intestinal obstruction,
trendelenberg position, tracheo-esophageal fistula, or massive
oropharyngeal bleeding. Cricoid pressure can help reduce
the amount of air being forced into the stomach and limit the
likelihood of vomiting. Nonetheless, gastric rupture has
been reported with face mask ventilation.
Recently, it was shown that independent risk factors for difficulties with mask ventilation include the
presence of beard, body mass index >26 kg/m2, lack of
teeth, age>55 years, and history of snoring.4
Patients with trauma to the pharyngeal mucosa may be at risk for
subcutaneous emphysema. Whenever continuous positive airway
pressure is applied to patients with basilar skull fractures, pneumocephalus may occur.
LARYNGEAL MASK AIRWAY
The laryngeal mask airway (LMA) has been
used in millions of patients and is accepted as a safe
technique. Muscle relaxation is unnecessary, laryngoscopy
is avoided, and hemodynamic changes are minimized during
insertion. However, numerous complications are associated
with the LMA. The tip of the epiglottis can be folded into
the vocal cords during placement, inducing labored breathing,
coughing, laryngospasm, and sometimes complete airway
obstruction. Excess lubricant can promote coughing or
laryngospasm. A known disadvantage of the device is its
inability to protect against pulmonary aspiration and
regurgitation of gastric contents. The incidence of
regurgitation of small amounts of gastric contents was reported
to be as high as 25%.5
However, the overall risk of aspiration and regurgitation using
the LMA is in the same low range as for endotracheal intubation
when the indications and contraindications of LMA usage are
respected.6
Laryngospasm and coughing may result from inadequate anesthesia, tip impaction against the glottis, or
aspiration. The incidence of sore throat is reported to be
7–12%, an incidence similar to that seen with oral airways.7
The incidence of failed placement is 1–5%, although this tends
to decrease with increasing operator experience. The LMA
cuff is permeable to nitrous oxide and carbon dioxide, which
results in substantial increases in cuff pressure and volume
during prolonged procedures. Increased intra-cuff
pressures may increase the incidence of postoperative sore
throat or cause transient dysarthria. Edema of the
epiglottis, uvula, and posterior pharyngeal wall may at worst
lead to airway obstruction. Hypoglossal nerve paralysis,
post-obstructive pulmonary edema, tongue cyanosis, transient
dysarthria, tension pneumoperitoneum and gastric rupture have
also been reported.
To minimize the risk of aspiration and regurgitation, the LMA-Proseale—a laryngeal mask with an
esophageal vent—was developed.8
Cases of gastric insufflation and aspiration have been reported
when this device was malpositioned.9
Branthwaite reported a case of laryngeal perforation leading to
mediastinitis and patient death following blind insertion of an
endotracheal tube through the intubating laryngeal mask airway
(ILMA).10
Contraindications for using an LMA include non-fasted patients, morbid obesity, necessity for high
inspiratory pressures (>20–25 cmH2O) in the presence
of low pulmonary compliance or chronic obstructive pulmonary
disease (COPD), acute abdomen, hiatal hernia, Zenker’s
diverticulum, trauma, intoxication, airway problems at the
glottic or infraglottic level, and thoracic trauma.
ESOPHAGEAL / TRACHEAL COMBITUBE
The Esophageal / Tracheal Combitube (Combitube) is an esophagotracheal double-lumen airway designed
for emergency use when standard airway management measures have
failed. Disregarding recommendations for use of the proper
size of the device (depending on the patient’s height) may cause
injury to the esophagus. Contraindications for using a
Combitube are intact gag reflexes, ingestion of caustic
substances, known esophageal disease, airway problems at the
glottic or infraglottic level, and latex allergy.
Obstruction of the upper airway, subcutaneous emphysema, pneumomediastinum and pneumoperitoneum
during resuscitation settings, and several cases of esophageal
lacerations or perforation have been reported.11,12,13
The incidence of sore throat with the use of this device is high.
OTHER SUPRAGLOTTIC AIRWAY DEVICES
There are many other devices available for
managing the airway at the supraglottic level: laryngeal tube,
ambu laryngeal mask, softseal laryngeal mask, laryngosed
streamlined linear of the pharynx, and perilaryngeal airway.
Most clinical problems are similar to those found with the LMA
(for example, aspiration) and result from dislodgement,
overfilling of cuffs, and insufficient depth of anesthesia.
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