- Improper face mask technique can result in continued
deflation of the anesthesia reservoir bag when the adjustable pressure-limiting valve
is closed, usually indicating a substantial leak around the mask.
In contrast, the generation of high breathing-circuit pressures
with minimal chest movement and breath sounds implies an obstructed
- The laryngeal mask airway partially protects the
larynx from pharyngeal secretions (but not gastric regurgitation),
and it should remain in place until the patient has regained airway reflexes.
- After insertion of a tracheal tube (TT), the
cuff is inflated with the least amount of air necessary to create
a seal during positive-pressure ventilation to minimize the pressure
transmitted to the tracheal mucosa.
- Although the persistent detection of CO2 by
a capnograph is the best confirmation of tracheal placement of a
TT, it cannot exclude bronchial intubation. The earliest manifestation
of bronchial intubation is an increase in peak inspiratory pressure.
- After intubation the cuff of a TT should not
be felt above the level of the cricoid cartilage, because a prolonged
intralaryngeal location may result in postoperative hoarseness and
increases the risk of accidental extubation.
- Preventing unintentional esophageal intubation depends
on direct visualization of the tip of the TT passing through the
vocal cords, careful auscultation for the presence of bilateral
breath sounds and the absence of gastric gurgling, analysis of exhaled gas
for the presence of CO2 (the most reliable method), chest
radiography, or use of fiberoptic bronchoscopy.
- Clues to the diagnosis of bronchial intubation include
unilateral breath sounds, unexpected hypoxia with pulse oximetry
(unreliable with high inspired oxygen concentrations), inability to
palpate the TT cuff in the sternal notch during cuff inflation,
and decreased breathing-bag compliance (high peak inspiratory pressures).
- The large negative intrathoracic pressures generated
by a struggling patient in laryngospasm can result in the development
of negative-pressure pulmonary edema even in healthy young adults.
Expert airway management is an essential skill for an anesthesiologist.
This chapter reviews the anatomy of the upper respiratory tract,
describes the necessary equipment, presents techniques, and discusses
complications of laryngoscopy, intubation, and extubation. Patient
safety depends on a thorough understanding of each of these topics.
Other than rendering a patient insensible to pain, no characteristic
better defines an anesthesiologist than the ability to “manage” an
airway and a patient’s
breathing. Successful intubation, ventilation, cricothyrotomy, and
regional anesthesia of the larynx require detailed knowledge of
airway anatomy. There are two openings to the human airway: the
nose, which leads to the nasopharynx (pars
nasalis), and the mouth, which leads to the oropharynx (pars oralis). These passages are separated
anteriorly by the palate, but they join posteriorly in the pharynx (Figure 5–1). The pharynx is a U-shaped
fibromuscular structure that extends from the base of the skull
to the cricoid cartilage at the entrance to the esophagus. It opens
anteriorly into the nasal cavity, the mouth, the larynx, and the
nasopharynx, oropharynx, and laryngopharynx (pars laryngea), respectively.
The nasopharynx ...