Week 5 Handout Flashcards
What are the intrinsic muscles of the larynx?
Cricothyroid, Vocalis, Thyroarytenoid, Lateral Cricoarytenoid, Posterior Cricoarytenoid, Aryepiglottic, Interarytenoid
These muscles are responsible for vocal cord tension, length, and position.
What is the function of the Cricothyroid muscle?
Tenses and elongates the vocal cords by tilting the thyroid cartilage.
Innervated by the external branch of the superior laryngeal nerve.
Which intrinsic muscle is responsible for adjusting tension in the vocal cords?
Vocalis muscle
Part of the thyroarytenoid muscle and innervated by the recurrent laryngeal nerve.
What is the primary function of the Thyroarytenoid muscle?
Relaxes and shortens vocal cords, aiding in voice modulation.
Innervated by the recurrent laryngeal nerve.
What does the Lateral Cricoarytenoid muscle do?
Adducts vocal cords and narrows the rima glottidis.
Innervated by the recurrent laryngeal nerve.
What is unique about the Posterior Cricoarytenoid muscle?
It is the only abductor muscle of the vocal cords.
Opens the vocal cords and widens the rima glottidis.
What is the function of the Aryepiglottic muscle?
Helps close the larynx during swallowing.
Innervated by the recurrent laryngeal nerve.
What are the components of the Interarytenoid muscle?
Transverse and oblique parts.
Adducts arytenoid cartilages, contributing to vocal cord closure.
What is the largest laryngeal cartilage?
Thyroid cartilage
Commonly known as the ‘Adam’s apple’. Provides protection to vocal cords.
What is the shape and function of the Cricoid cartilage?
Ring-like, broader at the back than the front; forms the base of the larynx and provides attachment for other cartilages and muscles.
Where are the Arytenoid cartilages located and what is their function?
Situated at the top of the cricoid cartilage; critical in vocal cord movement and voice production.
What is the role of the Cuneiform cartilages?
Provide support and stiffen the aryepiglottic folds.
What is the function of the Corniculate cartilages?
Support the aryepiglottic folds and aid in closing the larynx during swallowing.
What does the Trigeminal Nerve (Cranial Nerve V) innervate?
-Innervates the anterior two-thirds of the nasal cavity and nasal septum.
-Provides sensation to the anterior part of the nasal mucosa and soft palate.
-Maxillary and mandibular divisions contribute to the innervation of the mouth and anterior tongue.
What is the primary function of the Facial Nerve (Cranial Nerve VII)?
Motor nerve for facial expressions and contributes to taste sensation in the anterior two-thirds of the tongue.
What does the Glossopharyngeal Nerve (Cranial Nerve IX) provide?
Sensory innervation to the posterior third of the tongue, tonsils, pharynx, and middle ear.
What is the significance of the Vagus Nerve (Cranial Nerve X)?
Provides sensory and motor innervation to most of the larynx and pharynx.
What are the branches of the Superior Laryngeal Nerve?
Internal branch (sensory innervation above vocal cords) and external branch (motor innervation to cricothyroid muscle).
What does the Recurrent Laryngeal Nerve innervate?
Provides motor innervation to all intrinsic muscles of the larynx except the cricothyroid muscle.
What causes Unilateral Vocal Cord Paralysis?
Damage to one recurrent laryngeal nerve due to surgical trauma, tumors, or other medical conditions.
What are the symptoms of Unilateral Vocal Cord Paralysis?
Hoarseness, breathy voice, ineffective cough, aspiration risk.
What management options are available for Unilateral Vocal Cord Paralysis?
Voice therapy, surgical interventions like medialization thyroplasty, or injection laryngoplasty.
What causes Bilateral Vocal Cord Paralysis?
Damage to both recurrent laryngeal nerves, often associated with extensive surgical procedures or systemic diseases.
What are the symptoms of Bilateral Vocal Cord Paralysis?
Significant airway compromise due to inability to abduct vocal cords during breathing.
What management may be required for Bilateral Vocal Cord Paralysis?
Immediate airway intervention, such as tracheostomy, and potential surgical procedures to widen the airway.
What is the Mallampati Classification used for?
A non-invasive test to assess airway visibility and predict intubation difficulty.
What are the classes in the Mallampati Classification?
Class I: Full visibility of tonsils, uvula, soft palate; Class II: Visibility of hard/soft palate, upper tonsils; Class III: Visibility of soft/hard palate, base of uvula; Class IV: Only hard palate visible.
What are the limitations of the Mallampati score?
Not always accurate; should be used with other airway assessment tools; does not account for neck mobility or jaw movement.
What is the Mallampati score used for?
Airway assessment to predict intubation difficulty
It should be used in conjunction with other airway assessment tools.
What factors does the Mallampati score not account for?
Neck mobility and jaw movement
How is the Thyromental Distance measured?
Distance from the notch of the thyroid cartilage to the tip of the chin with the head in a neutral position
What does an adequate Thyromental Distance (≥6-7 cm) suggest?
Lower likelihood of difficult intubation and good neck mobility
What does a restricted Thyromental Distance (<6 cm) indicate?
Potentially difficult airway
Why is the Thyromental Distance important in airway management?
Guides the selection of intubation tools and techniques
What is the Inter-incisor Gap assessment method?
Measurement of the distance between the edges of the upper and lower incisors when the mouth is opened as wide as possible
What does an adequate Inter-incisor Gap (≥3-4 cm) suggest?
Normal jaw mobility
What may a restricted Inter-incisor Gap (<3 cm) indicate?
Limited jaw mobility due to various factors
What does the Mandibular Protrusion Test assess?
How far the mandible can be moved in front of the upper teeth
What does Class A or 1 in the Mandibular Protrusion Test suggest?
Easy intubation
What does Class C or 3 in the Mandibular Protrusion Test indicate?
Potentially difficult intubation
What is the role of the atlanto-occipital joint in airway management?
Crucial for achieving the sniffing position during intubation
What is the significance of reduced mobility at the atlanto-occipital joint?
It can indicate a difficult airway
What does the Cormack-Lehane grading system assess?
View of the glottis during direct laryngoscopy
What does Grade I in the Cormack-Lehane score represent?
Full view of the glottis
What is the importance of the Cormack-Lehane score in airway management?
Helps determine the need for alternative intubation techniques
What is the goal of the Difficult Airway Algorithm provided by the ASA?
Guide airway management strategies
What are indications for awake intubation?
Anatomical abnormalities, history of difficult intubation, risk of aspiration
What is Rapid Sequence Induction (RSI)?
An approach used when the airway must be secured quickly
What are the indications for using Rapid Sequence Induction?
High risk of aspiration and emergency situations
What is a precaution to take during Rapid Sequence Induction?
Avoid bag-mask ventilation after induction
What characterizes Regular Induction?
Gradual induction with confirmed fasting status
What is crucial to monitor during Regular Induction?
Continuous assessment of the airway and respiratory function
What should be done if the patient is asleep and can be ventilated?
Continue to ventilate while monitoring chest rise and EtCO2
Can we ventilate a patient who is asleep?
Yes, continue to ventilate the patient while monitoring chest rise and fall
Monitor End Tidal CO2 (EtCO2) waveform and peak airway pressures
What does the acronym ‘BONES’ refer to in difficult ventilation?
BONES stands for:
* Beard
* Obese (BMI > 26)
* No Teeth
* Elderly (> 55 years old)
* Snores
What are alternate techniques for managing difficult ventilation?
- Two-handed mask ventilation
- Place oropharyngeal airway or nasal trumpet
- Place supraglottic airway
- Attempt intubation
What are the general features of anesthesia face masks?
- Various shapes and sizes
- Typically made from clear, flexible materials
- Soft, cushioned rim
- Equipped with standard connectors
- May include valves and ports
What is the design of the Rendell-Baker-Soucek mask?
It has a more conical shape designed for pediatric patients
This design improves fit and reduces dead space
What is the technique for one-handed mask ventilation?
- Position your left hand in a C-shape
- Place the mask over the patient’s nose and mouth
- Seal the mask by lifting the jaw
- Use the right hand to squeeze the anesthesia bag
- Maintain airway patency with appropriate maneuvers
What are the advantages of two-handed mask ventilation?
- Improved seal
- Enhanced airway control
- Optimal use of force
What is the measurement method for an Oro-Pharyngeal Airway (OPA)?
Size is determined from the corner of the patient’s mouth to the angle of the jaw
What are the indications for using an Oro-Pharyngeal Airway (OPA)?
Used in unconscious patients to prevent tongue obstruction of the upper airway
What are the contraindications for using an Oro-Pharyngeal Airway (OPA)?
Not suitable for conscious patients or those with an intact gag reflex
What should be done before inserting a Naso-Pharyngeal Airway (NPA)?
Lubricate the NPA before insertion
What are the indications for using a Naso-Pharyngeal Airway (NPA)?
Useful in both unconscious and conscious patients, especially if oral access is not possible
What are the contraindications for using a Naso-Pharyngeal Airway (NPA)?
- Severe nasal trauma
- Cribriform plate injury
- Basilar skull fracture
- Transsphenoidal hypophysectomy history
- Coagulopathy
What types of Supraglottic Airway (SGA) exist?
- Laryngeal mask airways (LMAs)
- Laryngeal tubes
- i-gel airways
What are the advantages of using Supraglottic Airway (SGA)?
- Easier and quicker to insert
- Reduced risk of trauma to airway structures
- Useful in difficult airway scenarios
What are the absolute contraindications for using a Supraglottic Airway (SGA)?
- Risk of gastric content aspiration
- Inability to open the mouth
What does ‘RODS’ stand for in difficult supraglottic airway placement?
RODS stands for:
* Restricted Mouth Opening
* Obstruction
* Distorted Airway
* Stiff Lungs/Neck
What is the placement technique for Laryngeal Mask Airways (LMA)?
Inserted into the mouth and advanced along the hard palate until resistance is felt
What is the primary placement technique for LMAs?
Inserted into the mouth and advanced along the hard palate until resistance is felt at the hypopharynx
How is correct placement of an LMA verified?
By effective ventilation and the absence of air leak
What is the maximum recommended cuff pressure for LMAs?
60 cmH2O, with 40 to 60 cmH2O being the recommended range
What complications can arise from overinflation of the cuff?
- Nerve injuries * Pharyngeal necrosis
What is the maximum positive pressure ventilation (PPV) with LMAs?
Limited to 20 cmH2O
True or False: LMAs are suitable for surgeries with a high risk of aspiration.
False
List advantages of LMAs over endotracheal tubes.
- Easier and quicker to insert * Less invasive * Lower risk of trauma to the airway
What is the design of the LMA Classic?
Reusable silicone device with an inflatable cuff
What unique feature does the LMA Supreme have?
An integrated bite block and a gastric access channel
What is the purpose of the LMA Fastrach?
Designed for difficult airway management to facilitate intubation
What does the LMA C-Trach integrate?
An integrated camera and monitor for visualization of the larynx
What material is the cuff of the iGel made from?
Thermoplastic elastomer
What is the primary use of the Combitube?
Emergency airway management
How many lumens does the Combitube have?
Two separate tubes (dual-lumen)
What is a key limitation of the King Laryngeal Tube?
Does not allow for gastric decompression
The Macintosh blade is designed to fit into which anatomical space?
The vallecula
What is the mechanism of the Miller blade?
Lifts the epiglottis directly to expose the vocal cords
Which blade is preferred for infants and small children?
Miller blade
What is the primary advantage of direct vision laryngoscopy (DVL)?
Simplicity and widespread availability
What alignment is required for effective intubation during DVL?
Alignment of oral, pharyngeal, and laryngeal axes
Fill in the blank: The maximum cuff pressure for LMAs should not exceed _______.
60 cmH2O
What can nitrous oxide diffusion into the cuff during anesthesia lead to?
Increased cuff pressure necessitating monitoring and adjustments
What type of surgeries are LMAs indicated for?
General anesthesia where endotracheal intubation is not necessary
What are the axes that need to be aligned for direct laryngoscopy?
Oral, pharyngeal, and laryngeal axes.
What types of blades are typically used in direct laryngoscopy?
Curved blade (Macintosh) or straight blade (Miller).
What is a primary advantage of direct laryngoscopy?
Simplicity and widespread availability.
What is a limitation of direct laryngoscopy?
Can be challenging in patients with difficult airways.
What does video laryngoscopy use to visualize the vocal cords?
A laryngoscope equipped with a miniature camera.
What is a key advantage of video laryngoscopy?
Provides an enhanced view of the airway.
What is a limitation of video laryngoscopy?
Requires availability of specialized equipment.
What is the first step in preparing for direct laryngoscopy?
Ensure the laryngoscope is functioning correctly.
What is the recommended patient positioning for direct laryngoscopy?
Supine with the head in the ‘sniffing’ position.
What is the purpose of preoxygenation before laryngoscopy?
To denitrogenate the lungs and increase oxygen reserves.
What should be done to confirm the placement of an endotracheal tube?
Auscultate for bilateral breath sounds and observe chest rise.
What is the function of the pilot balloon on an endotracheal tube?
Indicates the status of the cuff (inflated or deflated).
What is a common indication for using an endotracheal tube?
During general anesthesia for surgeries.
What is a major advantage of endotracheal tubes?
Provides a secure, definitive airway.
What is a potential complication of endotracheal intubation?
Injury to teeth, larynx, or trachea during insertion.
What is the purpose of the Murphy Eye on an endotracheal tube?
Serves as an additional passage for air if the main opening is blocked.
What is the purpose of the cuff on an endotracheal tube?
Seals the space between the tracheal walls and the tube.
What is the maximum cuff pressure recommended for endotracheal tubes?
Less than 25 cmH2O.
What is the design feature of an Oral RAE Tube?
Curved at the distal end, directed anteriorly.
In what type of surgeries is the Oral RAE Tube particularly useful?
Oral or maxillofacial surgeries.
True or False: Video laryngoscopy requires direct line-of-sight visualization of the glottis.
False.
Fill in the blank: The _____ is used to inflate or deflate the cuff of an endotracheal tube.
Valve.
What is the purpose of preoxygenation in video laryngoscopy?
To saturate the lungs with oxygen and delay onset of hypoxemia.
What is the design of an Oral RAE Tube?
Curved at the distal end, with the curve directed anteriorly (towards the patient’s face)
What is the purpose of the Oral RAE Tube?
Designed for oral intubations where the tube needs to be directed away from the surgical field
What are the advantages of the Oral RAE Tube?
Keeps the tube out of the surgeon’s way and reduces pressure on teeth or gums
What is the design of a Nasal RAE Tube?
Similar to the Oral RAE but with a posterior curve (towards the patient’s nape)
What is the purpose of the Nasal RAE Tube?
Used for nasal intubations, particularly in surgeries where access to the mouth or airway is needed
What are the advantages of the Nasal RAE Tube?
Positions the tube away from the surgical field and is useful in head and neck surgeries
What is the design feature of a Reinforced (Armored/Flexible) Tube?
Features a spiral wire reinforcement within the tube wall, making it kink-resistant
What is the purpose of a Reinforced Tube?
Ideal in situations where tube kinking or compression is a concern
What are the advantages of a Reinforced Tube?
Prevents airway obstruction due to kinking, flexible for various surgical positions
What are Preformed (Shaped) Tubes used for?
Used in surgeries where standard ETT positioning might interfere with surgical access
What is the design of Double-Lumen Endobronchial Tubes?
Contains two separate lumens, one for each lung
What is the purpose of Double-Lumen Endobronchial Tubes?
Used in thoracic surgeries where it’s necessary to ventilate each lung independently
What are the advantages of Double-Lumen Endobronchial Tubes?
Allows for one-lung ventilation, essential in certain thoracic procedures
What is a Cuffed Tube?
Has a balloon at the end that can be inflated to create a seal against the tracheal walls
What is the purpose of Cuffed Tubes?
Used in adults and older children to prevent air leaks and aspiration
What is an Uncuffed Tube?
Lacks a balloon and is used mainly in pediatric patients
What is a Laser-Resistant Tube designed for?
Made with materials that can resist ignition during laser surgeries in the airway
What is the purpose of a Laser-Resistant Tube?
Used in surgeries involving laser use in the airway, like laryngeal procedures
What are Low Volume High Pressure (LVHP) cuffs characterized by?
Have a smaller internal volume and require higher pressure to achieve an adequate seal
What are the advantages of LVHP cuffs?
Effective in creating a seal in certain clinical situations
What are the disadvantages of LVHP cuffs?
Higher pressure increases the risk of ischemic damage to tracheal tissues
What are High Volume Low Pressure (HVLP) cuffs characterized by?
Have a larger internal volume and require less pressure to achieve an adequate seal
What are the advantages of HVLP cuffs?
Reduced risk of tracheal mucosal damage due to lower cuff pressure
What are the disadvantages of HVLP cuffs?
Potential for air leakage if not properly inflated
What is the design of the Eschmann Introducer?
Typically made of semi-rigid, flexible plastic or rubber
What is the purpose of the Eschmann Introducer?
Used in difficult airway situations and after failed intubation attempts
What is the function of the Cook Exchange Catheter?
Used for controlled ETT removal and replacement while maintaining airway access
What is a Bronchial Blocker used for?
Achieve lung isolation during one-lung ventilation (OLV)
What is a key feature of Bronchial Blockers?
Flexible, catheter-like structure that can be maneuvered into the desired bronchus
What are the types of Bronchial Blockers available?
- Arndt Endobronchial Blocker (Cook Medical)
- Cohen Flex-Tip Endobronchial Blocker
- EZ-Blocker (Teleflex)
- Univent Tube (Fuji Systems Corp.)
What precaution should be taken when using the Cook Exchange Catheter?
Risk of Barotrauma from excessive pressure during jet ventilation or oxygen insufflation
What is the function of the distal inflatable cuff of a Bronchial Blocker?
To occlude ventilation to one lung
What does the Bronchial Blocker allow?
Lung isolation without the need for a double-lumen tube.
What is the compatibility of the Bronchial Blocker?
Compatible with standard single-lumen endotracheal tubes.
Which placement technique ensures accurate bronchial occlusion?
Fiberoptic-guided placement.
List some indications for using a Bronchial Blocker.
- Thoracic surgery requiring one-lung ventilation
- Patients with difficult intubation
- Airway protection in unilateral pulmonary bleeding
- Pediatric patients requiring lung isolation
- Prolonged postoperative ventilation
What is a limitation of Bronchial Blockers?
High risk of displacement.
True or False: Bronchial Blockers always completely collapse the lung.
False.
What does the presence of a Bronchial Blocker increase?
Airway resistance.
What are key points for Fiberoptic Bronchoscopy for Intubation?
- Preparation and sedation
- Continuous oxygenation
- Skill and training
- Monitoring
- Tube advancement
What is the importance of patient positioning during Fiberoptic Intubation?
To optimize airway patency and patient comfort.
What should be continuously monitored during the procedure?
Patient’s vital signs and oxygen saturation.
Fill in the blank: The procedure requires proficiency in using a _______.
fiberoptic bronchoscope.
What are absolute contraindications for Fiberoptic Intubation?
- Severe oropharyngeal or nasopharyngeal pathology
- Uncooperative patients
What should be prepared before starting an awake fiberoptic intubation?
- Assessment of airway anatomy
- Explanation of the procedure
- Preparation of necessary equipment
What is a key step in the awake fiberoptic intubation process?
Gently inserting the fiberoptic bronchoscope through the nose or mouth.
What is a sign of proper endotracheal tube placement?
Bilateral breath sounds and monitoring for end-tidal CO2.
What is the first step in performing a Percutaneous Cricothyroidotomy?
Identification of landmarks.
What equipment is essential for a Percutaneous Cricothyroidotomy?
- Large bore cannula (e.g., 14-gauge IV catheter)
- High-pressure oxygen source
- Syringe
What angle should the cannula be inserted at during a Cricothyroidotomy?
45 degrees to the skin.
What is the purpose of transtracheal jet ventilation?
To ventilate the patient using short bursts of oxygen.
What is the initial step to confirm entry into the airway during retrograde intubation?
A percutaneous puncture of the cricothyroid membrane or trachea using a needle and syringe.
What is the purpose of the guidewire in retrograde intubation?
To be inserted through the needle and advanced through the vocal cords until it emerges from the mouth or nose.
What is the indication for using transtracheal jet ventilation?
Emergency situations where intubation is impossible and the patient cannot be ventilated by other means.
Fill in the blank: Transtracheal jet ventilation requires a cannula connected to a _______ capable of delivering about 50 psi.
high-pressure oxygen source.
What are the contraindications for transtracheal jet ventilation?
Children and patients with abnormal anatomy or pathology at the incision site.
What are the advantages of retrograde intubation?
- Provides an alternative route for securing the airway in difficult intubation scenarios.
- Useful in patients with restricted neck mobility or challenging visualization of vocal cords.
What are the potential complications associated with retrograde intubation?
- Bleeding
- Infection
- Injury to the airway and surrounding structures.
True or False: Retrograde intubation is commonly used nowadays due to advancements in fiberoptic intubation techniques.
False.
What is a key feature of the Bullard laryngoscope?
A distinctively curved blade that allows better navigation of anatomical structures.
What advantage does fiberoptic technology provide in the Bullard laryngoscope?
It provides a clear visual path to the vocal cords via an eyepiece or camera system.
What is the ergonomic design of the Bullard laryngoscope intended for?
To provide a comfortable grip and optimal control during intubation.
In what situations is the Bullard laryngoscope particularly useful?
In patients with difficult airways, limited neck mobility, obesity, or abnormal airway anatomy.
What is a lighted stylet also known as?
Lightwand.
What is the basic structure of a lighted stylet?
A malleable stylet with a light source at its tip.
What does the light source on a lighted stylet indicate?
That the tip is in proximity to or in contact with the tracheal rings or vocal cords.
Fill in the blank: The lighted stylet is inserted into an endotracheal tube and then introduced into the patient’s _______.
mouth.
What is the significance of transillumination in using a lighted stylet?
It indicates that the tip is in the trachea.
What type of scenarios is the lighted stylet used in?
Difficult intubation scenarios where direct laryngoscopy is not feasible or has failed.
What training considerations are necessary for effective use of the lighted stylet?
Specific training and skill are required to use it effectively.
What is a key consideration when using a lighted stylet to avoid complications?
Care must be taken to avoid excessive pressure with the stylet to prevent tissue damage.
What is the largest size ETT the LMA Fastrach (intubating LMA) will accommodate?
8.5 mm
What is the maximum cuff volume for a size 4 LMA?
30 ml
