Understanding Anesthesiology - The Global Regional Anesthesia ...

achieve good visualization of the larynx. As well, a
short thyromental distance may indicate inadequate
“space” into which to displace the tongue during laryngoscopy.
Combining Mallampati classification with thyromental
distance and other risk factors (morbid obesity, short,
thick neck, protuberant teeth, retrognathic chin), will
increase the likelihood of identifying a difficult airway.
No assessment can completely rule out the possibility
and so the clinician must always be prepared to manage
a difficult airway.
Laboratory investigations of the airway are rarely indicated.
In some specific settings, cervical spine x-rays,
chest ray, flow-volume loops, computed tomography
or magnetic resonance imaging may be required.
Airway Management
Airway patency and protection must be maintained at
all times during anesthesia. This may be accomplished
without any special maneuvers such as during regional
anesthesia or conscious sedation. If the patient is
deeply sedated, simple maneuvers may be required:
jaw thrust, chin lift, oral airway (poorly tolerated if gag
reflex is intact) or nasal airway (well tolerated but can
cause epistaxis).
During general anesthesia (GA), more formal airway
management is required. The three common airway
techniques are:
• mask airway (airway supported manually or with
oral airway)
• laryngeal mask airway (LMA)
• endotracheal intubation (nasal or oral)
The choice of airway technique depends on many factors:
• airway assessment
• risk of regurgitation and aspiration
• need for positive pressure ventilation
• surgical factors (location, duration, patient position,
degree of muscle relaxation required)
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