The normal airway begins functionally at the naresThe nose is the primary pathway for normal breathing.It’s functions:

•Warming

•Humidification

During quiet breathing the resistance to air flow throughThe nose accounts for nearly two-thirds of the total airwayResistance and is nearly twice compared to mouth

The pharynx

•Extends from sphenoid bone to C6 and cricoid cartilage•Is about 15 cm long •Consists of nasopharynx,

Oropharynx and laryngopharynx •Is widest (5cm) opposite the hyoid bone

And narrowest (1.5 cm) at it’s inferior end

Nasal cavity opens through the choanae, nasal passages and nostrilsinto the nasopharynx It extends from the skull base to the soft palate and has a respiratoryfunction On the lateral wall of the nasopharynx there is orificeof the auditory tube

Problems of the nasopharynx:

In the presence of basilar skull fractures entry into theCranium is possible. Pharyngeal tonsils (adenoids) isA site of potential obstruction or hemorrhage.

Fragility of the choanae may cause epistaxis

Oropharynx lies from the soft palate to the bottom of C3It has a digestive functionIt’s forward limit is the junction between the anterior two thirdsAnd posterior third of the tongue

ProblemsThe tongue is a principal source of oropharyngeal obstructionPalatoglossal folds contain tonsils, hypertrophy of whichMay cause difficulties in ventilation and intubationOral cavity: maxillary teeth can interfere with laryngoscopy

Larynx

The larynx lies at the level of the C3-C6

In adult males it is about 5 cm long

Serves as organ of phonation and as a valve for lower airway protection

The structure consists of muscles, ligaments,and a framework of cartilages

The laryngeal skeleton comprises nine cartilages

Three of them are single (thyroid, hyoid, and epiglottis), and threeare pared – arytenoid, corniculate, and cuneiform

Laryngeal ligaments and membranesIn the middle of C6, the cricothyroid membrane provides anEasily palpated and avascular site for emergency cricothyrotomy

The mucous membrane of the epiglottis reflects as the glossoepiglottic fold on the pharyngeal surface of the tongue. On either side of this fold are depressions called valleculae.

The vocal fold extends from thyroid cartilage anteriorly to the arytenoid cartilage posteriorly. Vocal fold consists of the vocal ligament, conus elasticus, muscle fibers, and mucous membrane. Apertura between vocal cords is called rima glottidis

The thyroid cartilage is the largest of the laryngeal cartilages.

The cricoid cartilage is the most inferior of the cartilages of larynx

Epiglottis functionally separates the larynx from pharynx and prevents aspiration by covering the glottis.

Indications for tracheal intubation

•Control of airway, it’s patency

•Prevention and protection against aspiration

•Resuscitation of a moribund patient

•Establishment of route for ventilation

•Fear that ventilation and intubation later on are impossible

Endotracheal tubes

•Most ET are disposable and made of clear polyvinyl chloride.•Length is marked in cm, and internal diameter in mm•High volume cuffs contact the trachea over a broad area, minimizing the pressure on the mucosa.•The standard ET has a bevel that opens toward patient’s left.•Fenestration on the tip of the tube protects against obstruction

Tracheal intubation

Tracheal intubation usually is performed after induction of anesthesia and muscle paralysis but may be accomplished in the conscious patient

Laryngoscopes

These instruments are designed to create a line of sight for passage of the ET by displacing the tongue and epiglottis anteriorly

Miller bladeMacintosh blade

It is important to recognize the structuresAnd not just insert deep and hope on the best!

If the epiglottis is not seen, the blade is, probably, too deep

In adult males, the tube is generally inserted to about 23 cm at the lips, in females – 21 (4 cm above carina)

Tubes inserted too far may cause endobronchial intubation.

A difficult airway can present as difficult mask ventilation, difficult intubation, or both

The major danger is “cannot intubate, cannot ventilate” situation

Some causes for difficult airway management

•Short, muscular neck•Limited neck mobility•Prominent maxillary teeth•Small mouth opening•Arthritis of cervical spine•Obesity•trauma

Oral Endotracheal Intubation

•Preoxygenation, rapid acting anesthetic, mask ventilation, relaxant•Head is in “sniffing position” or in manual stabilization

•The laryngoscope is held in left hand while fingers of right hand open the mouth.

•The laryngoscope blade is gently inserted into the right side of the mouth avoiding the teeth and tongue is taken to the left•Pressure on the teeth, lips or gums is avoided•After visualization of the epiglottis, the curved blade is inserted into vallecula•Laryngoscope is pulled upward and forward to expose the glottis•ETT is inserted

A rapid-sequence induction is employed when the patient is at particular risk for aspiration and intubation is not predicted as difficult

If there is any doubt, intubate coscious patient!

Patients at risk for aspiration

Full stomachTrauma Acute abdomenEsophageal diseasePregnancyobesity

                                      

            

                

Nasal Endotracheal Intubation

•ATLS recommends only in spontaneously breathing patients•In 90% is successful•May be blind or fiberoptic guided•Contraindications: coagulopathy, basilar scull fracture, severe intranasal disorder, presence of CSF leak•ET is inserted into the nose in the plane, perpendicular to the face•Tube is slowly inserted until maximal breath sounds are heard (it means that tube is just above the glottis) and then inserted during inspiration

Laryngeal Mask Airway

•Consists of an inflatable silicone ring attached diagonally to a flexible tube

•The ring forms an oval cushion which fills the space around the larynx

•It assists in the maintenance of a clear airway and is an alternative to a face mask

Laryngeal Mask: Advantages

•Provides a clear airway leaving hands free•Can replace ETT for many patients•Insertion is blind, easy and less traumatic•Is useful when intubation is difficult or impossible•Gives possibility of blind passage of a 6.0 diameter or smaller ET•Can be autoclaved for repeated use

Laryngeal Mask: Disadvantages

•LMA does not prevent regurgitation or aspiration. Does not fit for “full stomach”

•Laryngeal spasm may occur if the patient is anesthetized lightly

•Cost $135.00

Combitube

•A double lumen tube inserted blindly into the esophagus or trachea•The position of the tube is confirmed by the presence ofbreath sounds or capnography•Does not protect airways from aspiration, although gastric suction is possible through the gastric port

Combitube•Technisch unkomplizierte Einführung •Beatmung in ösophagealer und trachealer Lage möglich •weitgehender Aspirationsschutz •bei eingeklemmten, schwer zugänglichen Patienten •Komplikationsrate (zu tief plaziert, falsches Lumen beatmet) •hohe Kosten