Airway Part I Flashcards
During intubation with an ET tube, the tip of the MAC blade sits in what anatomical area?
The vallecula
The 5 anatomical features relevant to endotracheal intubation?
mnemonic (VEVAT)
- Vallecula
- Epiglottis
- Vocal cords
- Arytenoids
- Trachea
During direct laryngoscopy the tube is inserted at ________, then directed towards the ________, and tracheal placement is confirmed with a _________ ETC02 waveform, and esophageal waveform would be_________.
- The right corner of the mouth
- Glottis
- Alpha/Beta square
- Flat
In pediatrics the black line on the ETT should not pass how far pas the cords?:
- <6 months
- Up to 1 year
- Over 1 year
- 1cm
- 2cm
- 3-4 cm
Average ETT length at the interior incisors for:
- Males?
- Females?
- 23-24cm
- 21-22cm
What are the complications of ETT placement? (SHUN-GMTV)
- Sore throat
- Hoarseness
- Neurologic injury
- “Goose” (Gastric tube in the airway)
- Macroglossia
- Tracheal stenosis
- Vocal cord dysfunction
What instrument is used to visualize airway anatomical landmarks but cannot drive the tip of the ETT into the laryngeal inlet?
Bougie
An instrument that is always used in nasal intubation and can be used to direct a tracheal tube into the larynx or other devices into the esophagus.
Magill’s forceps
Laryngeal Mask Airways are inserted in the _______, creates a seal at the ________, and only protects from _______ secretions.
- Hypopharynx
- Larynx
- Pharyngeal
Because LMAs are a __________ device, they are not considered definitive airways.
Supraglottic devices.
A supraglottic device that can protect from gastric contents.
Proseal LMA
Parameters when positive pressure ventilating with an LMA.
- Limitied Tidal Volume < 8ml/kg
- Airway pressure < 20cm H20
LMA sizes…
- 1-6
- 1.5-2.5, 10kg intervals
- 3-4, 20kg intervals
- 5-6, 30kg or more intervals
> 1, up to 5kg
> 1.5, 5-10kg
> 2, 10-20kg
> 2.5, 20-30kg
> 3, 30-50kg
> 4, 50-70kg
> 5, 70-100kg
> 6, 100kg and more
Contraindications for LMA (DIM-HFF)
- Delayed gastric emptying (Diabetic gastroparesis)
- Intestinal obstruction
- Morbid obesity
- Hiatal hernia w/ GERD
- High-risk for gastric content aspiration
- Full stomach
Relative contraindications to LMA intubation (Increased risk for aspiration) (LASTPIG-NCPR-12)
- Laparoscopic surgery
- Airway obstruction (Supraglottic, glottic)
- Supraglottic pathology
- Trauma
- Prone
- Inflation pressures
- Gastric bypass
- Narcotics
- Cervical pathology
- Prolonged procedures
- Restricted access to airway
- 12 weeks pregnant
Complications FROM LMAs? (DANGBAT)
- Dislodment
- Aspiration
- Nerve injury
- Gastric distribution
- Bronchospasm
- Airway obstruction
- Trauma
This is an exaggerated and prolonged response of the protective glottic closure reflex, where airflow is absent, there is no vocal sound, and the true vocal cords cannot be seen, which can be caused by inhaled anesthetics, secretions and/or foreign bodies.
Laryngospasm
what do CRNAs need to anticipate
.Difficult airways
.Unanticipated difficult intubations or ventilations
.Failed airways
.Patients at risk for aspiration of gastric contents
.Patients who present with airway obstruction
Incidence of difficult mask ventilation
0.09%- 51.
What are the four treatments for laryngospasm?
1) Displace the mandible by pressing against the laryngospasm notch and extend the neck
2) Open the vocal cords with forced Oxygen pressure by bag-mask.
3) If Severe - give small dose of sux 0.15-0.30 mg/kg (approx 10-20mg)
4) Intubation (last resort)
Used to ventilate a patients with a mask, be sure you have a tight seal and avoid the eyes because you can accidentally cause this injury?
orneal abrasions
What wasThe average settlement payment for adverse respiratory events?
$200,000
with a range from $1,000 to $6,000,000.
settlement claims for injury due to difficult tracheal intubation averaged?
$76,000
Questions to ask patient about their Airway History:
Prior surgery or hospitalization requiring intubation or tracheostomy?
Prior history of difficult intubation?
Difficult Intubation Medic Alert Record?
History of obstructive sleep apnea?
History of oral, pharyngeal, esophageal disease?
Trauma, burns, chemicals, radiation ?
ways of reducing the risk of aspiration
- NPO orders
- Increase gastric pH (H2 antagonists)
Cimetidine, Ranitidine, Famotidine - Increase gastric motility
Metoclopromide
4. Caution with sedation and opioids: Decrease LES (Lower esophageal sphincter)
- Endotracheal intubation vs LMA
- Rapid sequence induction vs awake intubation
- Aspiration of gastric contents after intubation and prior to extubation
- Awake extubation vs deep extubation
What are the Four D’s that suggest a difficult airway
Dentition (prominent upper incisors, receding chin)
Distortion (edema, blood, vomitus, tumor, infection)
Disproportion (short chin-to-larynx distance, bull neck, large tongue, small mouth)
Dysmobility (TMJ and cervical spine)
what is the airway divided into?
upper and lower airway.
Upper Airway includes:
Nose Mouth Pharynx Hypopharynx Larynx
Lower Airway includes:
Trachea Bronchi Bronchioles Terminal bronchioles Respiratory bronchioles Alveoli
what are the functions of the nose?
The nose and mouth open to the respiratory tree
The nasal mucosa warms and humidifies inspired air
Provides 2/3 of resistance to breathing, Resistance is 2x that of mouth breathing
Blood supply to the nose?
The maxillary artery
Ophthalmic artery
Facial artery
The Spasming of the vocal cords in laryngospasm is caused by the stimulation of which nerve?
The Superior laryngeal nerve
Which stage of anesthesia is laryngospasm most commonly seen?
Stage 2/Excitatory Stage
What are the four treatments for laryngospasm?
1) Displace the mandible by pressing against the laryngospasm notch and extend the neck
Used to ventilate a patients with a mask, be sure you have a tight seal and avoid the eyes because you can accidentally cause this injury?
corneal abrasions
what are the 3 branches of the trigeminal nerve (V)?
- Anterior ethmoidal nerve - V1
Opthalmic division
Anterior third of the septum and lateral wall - Sphenopalatine nerves - V2
Maxillary division
Posterior 2/3rds of the septum and lateral wall - Lingual nerve - V3
Mandibular division
parts of the mouth?
- The soft palate:
Covers the posterior third to half of the oral cavity.
Rises during eating to prevent food and liquids from passing from the mouth into the nose and decreases aspiration
Is movable and can obstruct the airway!!!!!!! - The tongue:
A muscular organ relaxes when the patient is asleep or paralyzed causing obstruction!!!!!!!!!!!!! - The uvula:
Guards the airway, it can swell and cause obstruction - The tonsils:
Partially buried in the soft tissue and are protected by the anterior and posterior tonsillar pillars.
what separates the nasal passages from the mouth?
the hard and soft palate.
Functions of the Glossopharyngeal Nerve (IX)
Innervates. Posterior third of the tongue Roof of the pharynx Tonsils Soft palate Motor fibers to the stylopharyngeal muscle
what are the 3 compartments of the pharynx
Nasopharynx
Oropharynx
Hypopharynx
what is the larynx?
is a musculocartilaginous organ at the upper end of the trachea, below the root of the tongue, lined with ciliated mucous membrane, that is part of the airway and the vocal apparatus.
why is it important to Identify patients that are at increased risk for aspiration of gastric contents?
aspiration increases M&M.
1-7:10K cases M&M = 80% morbidity & 20% mortality
The cricoid cartilage is at:
The cricoid cartilage is at:
level C4-5
describe the larynx
the larynx is a Cartilaginous structure surrounded by ligaments and muscles, it Begins with the epiglottis and extends to the cricoid cartilage
what is the larynx composed of
Composed of: NINE CARTILAGES
3 single cartilages:
Epiglottis cartilage
Thyroid cartilage
Cricoid cartilage
3 paired cartilages:
Aretynoid cartilage
Corniculate cartilage
Cuneiform cartilage
Intrinsic and extrinsic muscles
Functions of the Larynx:
Protect the airway from aspiration
Provide airflow between the hypopharynx and the trachea
Provide cough and gag reflexes
Produce phonation
what are some situations that increase aspiration risks?
Loss of airway reflexes
Altered level of consciousness,
Ie, trauma, car accident
Full stomach
Anatomy – Obesity, Pregnancy, Hiatal hernia
Gastroespohageal Reflux Disease (GERD)
Decreased GI motility: diabetes, trauma
> Risk = pH < 2.5 and volume > 25 ml!!!!!
What is the pressure limit for mask ventilation?
20cm H20
What are the advantages to anesthesia delivery via facemask?
Lower incidence of sore throat
Less anesthetic depth
No muscle relaxants needed
What are the disadvantages to anesthesia delivery via facemask?
Your hands are tied up
Need higher flows
Need to continually assess and readjust airway
Work of breathing is greater
Five Facial characteristics that will contribute to difficulty with Mask ventilation?
1) Fat
2) Emaciated, edentulous faces
3) Protruding nares
4) Flat noses
5) Receding jaws
8 Facial characteristics that will contribute to difficult with Mask ventilation?
1) Male gender
2) A beard
3) Lack of teeth
4) Over the age of 55
5) Macroglossia
6) Obese
7) History of snoring
8) Increased Mallampati score
The following are complications of ____________?Dermatitis, Nerve injury, Gastric inflation, Eye injury, Environmental pollution, Jaw pain, Cervical spine movement, Latex allergy, No correlation between arterial and ETCO2, User fatigue.
Face Mask Ventilation
What are the 3 types of devices used to maintain a patent airway?
Oral Airways
Nasopharyngeal Airways
Laryngeal mask airway (LMA)
What are the five contraindications for Nasopharyngeal Airways?
1) Pt on anticoagulation
2) A basilar skull fracture
3) Pathology
4) Sepsis
5) Deformity of the nose or nasopharynx
What are the eight complications of airway devices?
1) Airway obstruction
2) Trauma
3) Tissue edema
4) Ulceration and necrosis
5) Dental damage
6) Laryngospasm and coughing!!!!!!
7) CNS trauma
8) Nerve Damage
The size of the ETT refers to the?
Internal Diameter
The sound-producing apparatus of the larynx consist of ?
- The two vocal cords and the intervening space
- The Rima glottides
A Leaf shaped lid of cartilage that protects this opening
epiglottis
What muscle are Adductors of the vocal cords and CLOSES the glottis?
Intrinsic Muscles
-Lateral Cricoarytenoid muscle
What muscle are Abductors of the vocal cord
and Separates the vocal cords and OPENS the glottis?
Intrinsic Muscles
-Posterior cricoarytenoid muscle
What muscle is a Tensor of the vocal cord and
Produces tension and elongates the vocal cord?
Intrinsic Muscles
-Crycothyroid muscle
What muscle Shortens and relaxes the vocal cord?
Intrinsic Muscles
-Thyroarytenoid muscle
What muscle closes the glottis, especially the posterior?
Intrinsic Muscles
-Arytenoids
Folds of the ________ play a significant role in the maintenance of the laryngeal functions of breathing and preventing food from entering the airway during swallowing.
Larynx
A fold of mucous membrane covering muscle in the larynx
Ventricular folds (False Vocal Cords)
The lower pair of vocal cords that enclose the lower part of the elastic membrane of the larynx, extend from inner surface of the thyroid cartilage near the median line to a process of the corresponding arytenoid cartilage on the same side of the larynx, and when drawn taut, subjected to the flow of breath produce voice
Vocal cords (True vocal cords)
An opening between the true Vocal folds forms a narrow slit, called the______
glottis
Trigeminal nerve (V) sensory supplies?
- V1 Opthalmic
- V2 Maxillary (sinus)
- V3 Mandibular
Glossopharyngeal nerve (IX) sensory supplies ?
Posterior third of the tongue to the uvula
Vagus Nerve (X) sensory supplies?
- Superior laryngeal
- Recurrent laryngeal
The superior laryngeal nerve innervates?
1) Internal branch- SENSORY
2) External branch- MOTOR
The recurrent laryngeal nerve innervates?
1) RIGHT recurrent laryngeal nerve
2) LEFT recurrent laryngeal nerve
Vagus nerve X (also known as Cranial nerve) innervates between
The epiglottis and vocal cords
Superior Laryngeal nerve (EXTERNAL BRANCH) is a MOTOR to ?
Crycothyroid muscle: Adductor tensor
-Tensor of the vocal cords
Superior Laryngeal nerve (INTERNAL BRANCH) is a SENSORY nerve to?
- Aryepiglottic folds
- Arytenoids
- Epiglottis: tongue base
- Supraglottic mucosa (Hypopharynx)
- Thyroepiglottic joint
- Cricothyroid joint
Motor: NONE
Recurrent Laryngeal nerve sensory MOTOR innervates the larynx below the vocal cords at ?
1) INTERARYTENOID: Posterior cricoarytenoid: Opens vocal cords
2) THYROARYTENOID: Lateral crcoarytenoid: Adduct the vocal cords
* *These muscles adduct the vocal cords and theerby close the rima glottidis, Protecting the airway!!!!!!!!!
Superior Laryngeal nerve (External branch) is a SENSORY nerve to?
Anterior subglottic mucosa
Recurrent Laryngeal nerve is a SENSORY nerve to?
1) Subglottic mucosa
2) Muscle spindles
Gag Reflex sensory innervation
1) AFFERENT pathway is SENSORY: Glossopharyngeal nerve
2) EFFERENT pathway is MOTOR: Vagus nerve
Results in hoarseness but does not compromise respiratory status
Unilateral injury to the RLN (Recurrent laryngeal nerve)
Results in stridor, which may deteriorate into: Severe respiratory distress
Bilateral injury to the RLN (Recurrent laryngeal nerve)
Usually does NOT cause respiratory distress
Injury to the SLN (Superior Laryngeal nerve)
Surgical Incision made through the skin and cricothyroid membrane to establish a patent airway during certain life threatening situations
Cricothyrotomy
Connects the thyroid and cricoid cartilage, located below the thyroid cartilage
Cricothyroid Membrane
Trachea
-Suspended from the cricoid cartilage by the cricotracheal ligament
-1st tracheal ring is anterior to C6
-Trachea ends at the carina, level T5
-Tracheal length approx. 15cm (adults)
-Originates from the inferior border of the cricoid cartilage and extends to the carina
-It is 10-20cm long in adults
-Cricoid cartilage is a complete ring:
-The remainder of trachea is composed of
16-20 C-shaped cartilaginous rings
-Right mainstem bronchus:
Angle is 25-30 degrees!!!
-Left mainstem bronchus:
Angle is 45 degrees!!!!!!
Where should you mark (measure) the ET tube after insertion?
At the teeth or lips after intubation, in centimeters
When placing ET tube where should you place the marks?
When there are two marks, place the vocal cards between the marks when there is only one, the mark should be at the vocal cords
What is the slant at the end of the ET tube called and why is the this important ?
The slant is called a bevel and when present the left facing bevel gives a better view
What is the Murphy Eye in the ET tube?
If the main opening of the ET tube gets blocked gas flow can still occur via the Murphy eye
Without the Murphy eye the ET tube would be completely obstructed, if blocked in any way.
What is the purpose of the ET tube cuff?
Forms a seal against tracheal wall
Prevents gases from leaking pasts the cuff
Allows positive pressure ventilation
Prevents aspiration
How do I inflate the ET tube cuff?
A syringe is attached to the pilot balloon and inflated, syringe is removed, the air does not leak because it is a one way valve.
The high volume low pressure cuffs have what effect on the trachea?
Less risk of tracheal ischemia
The low volume high pressure cuffs have what effect on the trachea?
Higher risk of tracheal ischemia
Why would you use a preformed RAE tube?
North RAE tubes and South RAE tubes allow easy access for dental and ENT surgeons
What is special about a pediatric ET tube?
They are uncuffed, even if a cuffed tube is used it is not inflated to prevent damage to the trachea
What does the reinforced ET tube prevent?
Kinking, used for thyroidectomy and surgery, has spiral wire embedded into the wall of the ET tube to give it strength and flexibility
Are there special tubes for use with Laser?
Yes, special ET tubes resist damage by laser beams
What safety measures are built in to ET tubes to prevent airway fires?
Cuff filled with methylene blue saline.
If cuff is damaged the blue color will identify rupture and saline will help prevent an airway fire.
What are the advantages of routinely using cuffed ET tubes in adults?
Accurate ETCO2, TV, and compliance monitoring
Decrease aspiration
Less OR pollution
*Must use smaller diameter in children
What are important considerations when using uncuffed tube in children
The tube should be large enough to provide effective ventilation
Maintain leak at 20-25 cm H2O
When using a stylet care should be taken to avoid this?
Prevent stylet going through Murphy Eye and perforating the trachea
Physical Characteristics Associated with Difficult Intubation?
Obesity Limited head and neck movement Jaw movement Receding mandible Buck teeth High mallampati score Male sex Age 40-59 Decreased mouth opening Short thyromental distance Short neck Maxillary incisor characteristics
Mallampati Classification descriptions?
Class 1: Soft/hard palates, fauces, pillars, uvula
Class 2: Soft/Hard palate, fauces, portion of uvula
Class 3: soft/hard palate, base of uvula
Class 4: Hard palate only
Laryngeal View different Grades classification?
Grade 1: Full view of the glottis
Grade 2: Only the posterior commissure is visible
Grade 3: Only the epiglottis is seen
Grade 4: No epiglottis or structures visible
How is the Thyromental Distance measured?
Tip of thyroid cartilage to the tip of the chin (mentum). Mandibular space length between the thyroid notch and the inner border of the mandible with the head extended.
- Difficulty of Thyromental Distance >6cm?
3 fingerbreadths: Indicates easy intubation
- Difficulty of Thyromental Distance 6.0-6.5 cm?
Intubation maybe difficult but may be possible
- Difficulty of Thyromental Distance <6 cm?
Intubation maybe impossible
- Airway Assessment includes?
A. Head and neck extension:
Range of motion.
Patient should touch the tip of the chin to the chest.
Ability to place the patient in the sniffing position
- Neck flexed on chest 35 degrees and neck extension 80 degrees
B. Body weight
C. Mallampati classification:
Relates the size of the base of the tongue to the oral cavity
What is the Sniffing Position and the importance?
Proper positioning of the head is essential to facilitate success with mask ventilation and tracheal intubation.
Requires the head to be flexed forward 35 degrees and extended 80 degrees.
Allows for alignment of the oral, pharyngeal, and tracheal axis.
Define the Lemon Law Assessment?
- Look Externally: Look at the patient’s characteristics known to cause difficult laryngoscopy, intubation, and ventilation
- Evaluate 3-3-2
3 fingerbreadths between incisors
3 fingerbreadths between tip of the chin and hyoid bone
2 fingerbreadths between hyoid bone and thyroid notch
-Mallampati score
What class is the pt?
-Obstruction
Listen to respiration
-Neck mobility
Range of motion
Congenital Syndromes Associated with Difficult Intubation?
Trisomy 21 Goldenhar Klippel-Feil Pierre Robin Treacher Collins Turner
Aspiration of Gastric Contents highest percentage of occurrence?
Induction 60%
What’s the Sellick’s Maneuver?
Pressure on cartilage: pushes trachea more posterior for visualization of vocal cords intubation. Compresses esophagus to inhibit vomiting.
