Intubation and anatomy of airway and Anesthesia apparatus

Intubation and anatomy of airway and Anesthesia apparatus Tasneem Al-Abbadi

Objectives: 1. The anatomical structures seen in region of intubation 2. Different classifications of airway structures 3. The technique of tracheal intubation 4. Assessment of patients airway including 1 -2 -3 -Test 5. Laryngoscopes and type of blades 6. Tracheal tubes: size and types of tubes Shape of tube and specialized tubes • 7. the laryngeal mask • 8. Other apparatus including oro- and nasopharyngeal airways. • 9. Potential complications of intubation • • •

Different classifications of airway structures ANATOMY OF RESPIRATORY TRACT Anatomically into upper and lower tract in relation to vocal cord: Upper: nose, mouth, pharynx, larynx, trachea, and mainstem bronchi. Lower: bronchioles , terminal bronchioles, Respiratory bronchioles , alveolar ducts, alveolar sacs, alveoli. Or according to its function into conducting zone and respiratory zone Conducting zone : Nose, pharynx, trachea, bronchioles , terminal bronchioles Function: filter, warm and moisten air and conduct air to and from the respiratory zone Respiratory zone : Respiratory bronchioles , alveolar ducts, alveolar sacs, alveoli Function : gas exchange

pharynx • fibromuscular structure that extends from the base of the skull to the cricoid cartilage at the entrance to the esophagus. • 3 part? ? • It opens anteriorly into the nasal cavity, the mouth, the larynx, and the nasopharynx, oropharynx, and laryngopharynx, respectively.

At the base of the tongue, the epiglottis functionally separates the oropharynx from the laryngopharynx (or hypopharynx). epiglottis prevents aspiration by covering the glottis—the opening of the larynx during swallowing

LARYNX • cartilaginous skeleton held together by • ligaments and muscle • Located below the tongue and hyoid bone, between the great vessels of neck. • Level of C 4 -C 6 • 44 mm in males and 36 mm in females* • 9 cartilages of larynx – – – Thyroid Cricoid 2 arytenoid 2 corniculate 2 cuneiform Epiglottis

Muscles of the larynx The muscles of the larynx can be divided into two groups; the external muscles and the internal muscles. The external muscles act to elevate or depress the larynx during swallowing. In contrast, the internal muscles act to move the individual components of the larynx – playing a vital role in breathing and phonation The intrinsic muscles are divided into respiratory and the phonatory muscles (the muscles of phonation). The respiratory muscles move the vocal cords apart and serve breathing. The phonatory muscles move the vocal cords together and serve the production of voice. The extrinsic, passing between the larynx and parts around; and intrinsic, confined entirely. The main respiratory muscles are the posterior cricoarytenoid muscles why?

INTRINSIC MUSCLES OF LARYNX

EXTRINSIC MUSCLES OF LARYNX • • • Sternothyroid muscles depress the larynx. Omohyoid muscles depress the larynx. Sternohyoid muscles depress the larynx. Inferior constrictor muscles Thyrohyoid muscles elevates the larynx. Digastric elevates the larynx. Stylohyoid elevates the larynx. Mylohyoid elevates the larynx. Geniohyoid elevates the larynx. Hyoglossus elevates the larynx. Genioglossus elevates the larynx

INNERVATION OF LARYNX • SENSORY (mucosa) – Above the vocal cords by the internal laryngeal br of the superior laryngeal br of vagus – Below the vocal cords by the recurrent laryngeal N. • MOTOR – All intrinsic ms of larynx are supplied by the recurrent laryngeal N except the cricothyroid ms ( by external laryngeal branch)

TRACHEA • A cartilaginous and membranous tube • Begins as a continuation of the larynx at the lower border of cricoid cartilage at the level of C 6, and terminates at the carina, at the level of T 5. • Adults – 10 -16 cm long and 2. 5 cm in diameter • Infants – 4 -5 cm long and may be as small as 3 mm in diameter • Kept patent by the presence of C-shaped cartilaginous rings

AIRWAY ASSESSMENT • A preanesthetic airway assessment is mandatory before every anesthetic procedure. • The goal of evaluating a patient's airway is to identify any possible problems with maintaining, protecting, and providing a patent airway during anesthesia.

Assessment of patients airway including 1 -2 -3 -Test • to assess several factors that may affect decisions concerning the patient’s airway management. • ‘ 1 -2 -3’ TEST COMPONENTS: 1. TMJ MOBILITY 2. MOUTH OPENING 3. THYROMENTAL DISTANCE

FIRST RULE: TEMPOROMANDIBULAR JOINT (TMJ) MOBILITY To identify any restricted mobility of the temporomandibular joint (TMJ) 1. Ask the patient to sit up with his head in the neutral position 2. open his mouth as wide as possible. -The condyle should rotate forward freely such that the space created between the tragus of the ear and the mandibular condyle is approximately one fingerbreadth in width.

SECOND RULE : Mouth Opening(insicor distance) and tongue protrusion 1. Ask the patient to open his mouth as wide as he can. The aperture of the patient's mouth should admit at least 2 fingers (3 cm) between his teeth, on the other hand, It will be difficult to insert the laryngoscope blade on less than 2 fingers. Don’t forget to look for any missing or dentally worked teeth (Caps, bridges …. Why? )

2. Ask the patient to protrude his tongue maximally. The structures visualized should include: 1) 2) 3) 4) 5) 6) The pharyngeal arches. Uvula. Soft palate. Hard palate. Tonsillar beds. Posterior pharyngeal wall. PUP TOP

Mallampati Classificatin In intubation we care only when the tongue and soft palate are seen. (Mallampati 3&4)

THIRD THE RULE : THYROMENTAL DISTANCE This is the distance between the mentum (chin) and the superior thyroid notch. A distance greater than 3 fingerbreadths is desirable, adults who have less than 3 fingerbreadths may have either an anterior larynx or a small mandible, which will make intubation difficult.