Manual Ventilation Flashcards
Functions of the Nose
- Humidify Air
- Transport Air
- Heating and Warming Air
- Sense of Olfactory
- Filter Air
External Nose
External Nares-There are two flared openings called alae
Vestibule-The most anterior portion of the nasal cavity before the alae
Anterior Nares-Located posterior to the vestibules are openings to the internal nose
Internal Nose
AKA nasal cavity
The nasal cavity extends from the anterior nares to the internal nares
The nasal cavity is tilted slightly downwards (10-15 degrees) from the front to the back
Epiglottis
Protects the airway by preventing food from entering
Little’s Area (Kiesselbach’s Plexus)
A highly vascular area located on the anterior aspect of the nasal septum in each nostril
Most nosebleeds will often originate from this area
Pharynx
A tube connecting the nasal cavity, mouth, larynx, and esophagus
Approximately 13 cm in length (in adults)
Extends from the base of the skull to the cricoid cartilage (at level of C)
Muscular wall is composed of skeletal muscle-This means that there is voluntary control which allows us to hold our breath
Nasopharynx
In theory it is a passage for air alone
Extends from the base of the skull to the uvula
Contains pharyngeal tonsils (adenoids) and tubal tonsils
5 Openings to Nasopharynx
The nasopharynx contains 5 openings which is important during intubation as we can have infection
These openings are
- 2 eustachian tubes
- 2 Internal nares
- 1 opening to the oropharynx
Oropharynx
Extends from tip of uvula to upper rim of the epiglottis
Common pathway for food and air
Contains palatine tonsils, which are commonly removed during tonsillectomy
Larynx
Conducts air into the lungs
Acts a switch mechanism to ensure that food bypasses the trachea and proceeds down the esophagus
Larynx is the most heavily sensory inervated organ in the body.
Stimulation of unaesthetized larynx causes very strong sympathetic response-HR and BP may double.
Phonation
True vocal cords located in larynx will vibrate as air passes between them through the glottis
Defenses in the Larynx
Pseudostratified ciliated columnar epithelial cell sit below the vocal cords and sweep mucus up into the pharynx continually
Larynx-Breath Hold, Effort closure and cough
Muscular vestibular folds (false vocal cords help to close the glottis tightly)
Valsalva Maneuver-performed by moderately forceful attempted exhalation against a closed airway, usually done by closing one’s mouth, pinching one’s nose shut while pressing out as if blowing up a balloon
Cartilage of the Larynx
There is 9 Cartilages of the Larynx
- 2 Arytenoid Cartilages
- 2 Cuneiform Cartilages
- 2 Corniculate Cartilages
- 1 Thyroid Cartilage
- 1 Cricoid Cartilage
- 1 Epiglottis Cartilage
Trachea
When we are intubating we want to go into the trachea we have to manipulate things because if we don’t manipulate things then the path of least resistance for intubation is through the esophagus
If doing an emergency cricoid cartilage you don’t have to go through the cric you can go through a ring that is not continuous but C shaped
Thyroid Cartilage
Thryroid cartilage forms anterior wall of larynx
Functions of the Trachea
- Conducts air in and out of the lungs
- Contraction of trachealis muscle can accelerate expired air to excel mucous during a cough
Trachea Measurements
Extends from the larynx to the main stem bronchi 12-15 cm in length and ~2 cm in diameter 16-20 C-shaped cartilage rings
Carina Topography
Carina sits behind “angle of Louis” anteriorly and level of T4 posteriorly
Patent Airway
Airway Patency is the state or quality of the airway being open, expanded, or unblocked
If you are bagging and not ventilating the patient reapply the mask and that is the most common cause
Loss of Airway Patency
Causes of loss of airway patency can be divided into 2 general categories
Central Causes-Any condition that leads to a depression of the CNS (i.e. <8)
Peripheral Causes-Airway obstruction caused by something originating outside the body
Jaw Thrust
The jaw thrust will move the tongue from the back of the throat
Central Causes-Decrease in Cardiac Output
Acute myocardial infarction (MI)
Cardiac tamponade-But when cause through a infection it is considered to be a peripheral cause
CHF
V fib or V tach
Hypovolemic Shock
Septic Shock
Massive Pulmonary Embolism
Mechanisms of Upper Airway Obstruction
Decrease in tone of submandibular muscles leads to posterior displacement of tongue against the posterior pharyngeal wall
While in a comatose state the position of the chin will worsen the obstruction
C-spine adopts a semi flexed position, narrowing the distance between the tongue and posterior pharyngeal wall
Epiglottis gravitates towards the larynx partially occluding the airway
Negative pressure cause by respiratory efforts in presence of obstruction draws tongue towards the airway
Peripheral Causes
- Peripheral causes come from outside of the body
- Infection
- Abscess
- Neoplastic (carcinomas)
- Physical and Chemical Agents
- Thermal
- Caustic Injuries- Can cause swelling
- Inhaled toxins
- Allergic/Idiopathic
- Traumatic
Signs of Loss of Airway Patency
Tachypnea and dyspnea
Noisy snoring respirations
Paradoxical breathing
Tracheal tug or retractions
Nasal flaring-Usually seen in babies
Expiratory Grunting-Is a compensation for collapse that is usually seen in babies
Cardiac dysrhythmias
Pressure in chest and low oxygen levels will affect the heart
Stridor
Absence of breath sounds or visible chest movement
Cyanosis
Peripheral Causes-Infection
Viral and bacterial infection laryngotracheobronchitis (e.g. croup)
Parapharyngeal and retropharyngeal abscess
Lingual tonsillitis
Hematomas or abscess of the tongue or floor of the mouth
Epiglottitis (also known as supraglottitis)
Similar to croup but the patient will have low energy and is very serious and in this case we do not manipulate the airway
Peripheral Causes-Neoplastic
Laryngeal carcinomas Hypopharyngeal and lingual (tongue) carcinomas
Peripheral Causes-Physical and Chemical Agents
Foreign bodies Chocking something shoved up a nose Thermal injuries-Can cause swelling Caustic Injuries- Can cause swelling Inhaled toxins
Peripheral Causes- Allergic/Idiopathic
Angiotensin converting enzymes inhibitors induced angioedema
Peripheral Causes- Traumatic
Blunt and penetrating neck and upper airway trauma