anaesthesia.Airway evaluation and management 1.(dr.amr)Presentation Transcript
Airway Evaluation and Management
Key Learning Objectives
Review the anatomy relevant to airway management
Understand the components of an airway examination
Learn the principles of mask ventilation and intubation
Despite the site of surgery or the anesthetic technique chosen, every patient receiving anesthetic care is exposed to a varying degree of risk of airway compromise. That is, all levels of sedation, general anesthesia, and regional anesthesia carry with them at least a small risk of airway obstruction and apnea.
Therefore, every anesthesia provider must examine each patient in anticipation of a need to mechanically ventilate and intubate, regardless of whether or not such interventions were part of the primary anesthetic plan. A thorough airway examination and history, combined with expert airway management, guard against the life-threatening risks of airway obstruction and apnea.
The human airway is a dynamic structure that extends from the nares to the alveoli.
Obstruction can occur at any point because of anatomic collapse or a foreign body
which includes liquids such as mucous, blood, and gastric contents
The pharynx is basically a wide muscular
tube forming the common upper pathway of alimentary
and respiratory tracts. It extends from the base of the skull
to the level of C6.
The pharynx lies posterior to, and communicates with,
the nose, mouth and larynx. This relationship
divides the pharynx into three sections: naso-, oro and
Laryngo pharynx. The posterior surface of the pharynx
lies on the prevertebral fascia and cervical vertebrae.
The larynx is a functional sphincter at the beginning of the respiratory tree to protect the trachea from foreign bodies. It is lined by ciliated columnar epithelium and consists of a framework of cartilages
linked together by ligaments which are moved by a series of muscles.
Cartilages of the larynx
The thyroid cartilage is said to be shaped like a
shield. It consists of two plates that join in the
midline inferiorly to form the thyroid notch (Adam’s
apple). Each plate has a superior and inferior horn or cornua at the upper and lower limit of its posterior border, respectively. The inferior horn articulates with the cricoid cartilage.
The cricoid cartilage is shaped like a signet ring, with the large laminal portion being posterior.
Each lateral surface features a facet that articulates with the inferior horn of the thyroid cartilage. The upper border of the lamina has an articular facet for the
There is a pair of arytenoid cartilages , each shaped like a triple-sided pyramid possessing medial, posterior and anterolateral surfaces.
Each arytenoid cartilage projects anteriorly as the vocal process and in a similar fashion laterally as the muscular process.
The posterior and lateral cricoarytenoid muscles are inserted into the muscular process.
The epiglottis is a leaf-shaped cartilage. It has a lower tapered end which is joined to the thyroid cartilage by the thyroepiglottic ligament.
The free upper end is broader and projects superiorly behind the tongue.
The lowest part of the anterior surface of the
epiglottis is attached to the hyoid by the hyoepiglottic ligament.
Two other minor cartilages are the corniculate and the cuneiform.
Ligaments of the larynx
Extrinsic ligaments are the:
thyrohyoid membrane, cricotracheal, cricothyroid, and hyoepiglottic ligaments.
The intrinsic ligaments of the larynx are of minor importance, being the capsules of the small synovial joints
Muscles of the larynx
Sternothyroid, thyrohyoid and inferior constrictor is a constrictor of the pharynx
Intrinsic group: These are paired, with the exception of the ( transverse arytenoid).
The mucous membrane of the larynx above the vocal cords is supplied by the internal laryngeal nerve, that below by the recurrent laryngeal nerve.
All muscles of the larynx are supplied by the recurrent laryngeal nerve except for the cricothyroid, which is supplied by the superior (also known as external) laryngeal nerve.
The trachea descends from the lower border of the cricoid
cartilage (C6) to terminate at its bifurcation into the two
main bronchi at the sternal angle (T4). The length of the
adult trachea varies between 10 and 15 cm. The walls of
the trachea are formed of fibrous tissue reinforced by 15–
20 incomplete cartilaginous rings. Internally the trachea
is lined by respiratory epithelium. The trachea may be
divided into two portions, that in the neck and that in the
At the carina, the two main bronchi arise. The right
main bronchus is shorter, wider and more upright than
the left. The right pulmonary artery and azygos vein are
intimately related to the right main bronchus. The left
main bronchus passes under the aortic arch anterior to
the oesophagus, thoracic duct and descending aorta. The
structure of the extrapulmonary bronchi is very similar to
that of the trachea.
Branching of the intrapulmonary bronchi gives rise to
functional units – the bronchopleural segments.
usually simply referred to as intubation , is the placement of a flexible plastic or rubber tube into the trachea to maintain an open airway or to serve as a conduit through which to administer certain drugs.
Modified for variety of specialized applications:
Flexible, wired-reinforced (armored), rubber,
Microlaryngeal, oral/nasal RAE, double lumen, cuffed non cuffed.
All endotracheal tubes has a radio-opaque line.
Airflow resistance depends on tube diameter, curvature and length.