Exam 2 - Airway Equipment (Ericksen) Flashcards
What does the face mask allow for?
- gas admin to pt from breathing system w/o any apparatus in pts mouth
What is the goal of providing mask ventilation to a pt?
- provide pos. pressure gas movemement through the pts unprotected airway
- there is nothing in the airway to prevent aspiration
- LES relaxes - food comes up
What are 2 examples of when we would use a face mask?
- preoxygenation/denitrogenation (induction to get best chance of successful intubation w/o de-satting)
- entire anesthetic case
What are examples of surgeries/procedures where a face mask can be used to ventilate for the entire anesthetic?
- ear tubes
- elderly ear wax removal
- non-invasive cases that don’t need invasive airway
Components of the face mask
Body:
- transparent
- provides the shape
Components of the face mask
Seal:
- inflatable cushion
- maintenance of airway pressure 20-25cmH2O w/ minimal leak (this is good)
Components of face mask
Connector:
- 22mm internal diameter
- circular ring w/ prongs for straps
Components of face mask
What 3 other things may be included on/with a face mask?
- pacifier - infants (keep them comfy while they inhale the gas)
- ports for bronch or upper endoscopy
- Scents for pedi
Face Mask Ventilation
One-handed method:
- how should hand be positioned?
- what do we need to be cautious of?
- considerations for children:
- form a C w/ 3 fingeres on the ridge
- make sure we are not compressing the facial nerve/artery (watch where palm is)
- children - use less fingers (3 total)
Face Mask Ventilation
Two-handed method/Technique:
* what are examples when we would need to use this?
- someone else will be bagging for you
- lots of adipose, edentulous
- helps create a better seal to better ventilate pt
Difficult Mask Ventilation
MOBEOB
Many Otters Bring Extra Oranges Back
* M: male
* O: over 55
* B: beard
* E: edentulousness
* O: OSA/snoring
* B: BMI > 30kg/m2
What 4 techniques can we use to overcome difficult mask ventilation?
- oral airway, nasopharyngeal airway
- two-handed technique
- cut the damn beard
- tegaderm over the beard/mouth
What happens if despite adjuncts, we still cannot mask ventilate?
go to the emergency adjunct difficult airway algorithm)
When is it good to use mask straps?
- helpful for people w/ small hands & pts w/ big faces (edentulous/big beards)
- if you need your hands free to do other things
With what type of ventilation can we use mask straps?
What do we need to ensure before placing them?
- can only be used for spontaneous ventilation
- need to ensure pt is asleep and comfortable (claustrophobic)
How does an OPA (oropharyngeal airway) work?
- lifts the tongue & epiglottis away from the posterior pharyngeal wall
- relieves airway obstruction
- decreases the WOB during spont. ventilation
What position can make airway opening better?
What causes obstruction r/t anesthesia?
- sitting the pt up can open the airway
- when we put the pt to sleep - everything falls back toward posterior pharyngeal wall and obstructs the airway
When can an OPA be placed an removed?
- placed: after pt is under anesthesia & if they are still obstructing after positioning changes
- removed: when they are awake enough to remove it themselves
How are OPAs designed?
- most made of plastic
- bite portion needs to be firm enough that pt cannot close lumen from biting
- sizing: color coded/size on the side in mm
How do we measure a pt for an OPA?
- corner of mouth to the angle of the jaw or the earlobe
What should be depressed before we insert an OPA?
- pharyngeal and laryngeal reflexes
- they don’t have to be paralyzed - just sleepy & reflexes depressed
What potential things can happen if a pt is not deep enough and we try to place an OPA?
- vomiting
- coughing/spit it out
- pt takes it out
- laryngospasm/bronchospasm
- we usually only see problems on induction w/ OPAs - not emergence
What are the 2 methods of insertion for an OPA?
- upside down method - can get caught on tissue
- tongue depressor method
- Dr. Ericksen lifts the jaw w/ 4x4s and places it
Where (anatomically) is a bite block placed?
- b/w the upper and lower teeth/gums
What does a bite block prevent and where do we use them?
- prevents biting on ETT, bronchoscope, endoscope
- used in endoscopy & out pt procedures
When are the 2 best times to place a bite block?
- When the pt is awake and give them directions to hold down on it
- w/ the propofol yawn
after this the pts jaw will be tight and it will take a while to relax
Who are nasopharyngeal airways (NPA) tolerated in?
What situations are NPAs preferable in?
- pts w/ intact airway reflexes
- preferable w/ loose teeth, oral trauma, gingivitis, limited mouth opening
What are the 5 contraindications for an NPA?
- basilar skull fx
- nasal deformity
- Hx of epistaxis (not absolute contraindication)
– depends on pt & what is going on w/ them
– on anticoagulants = NO NPA - pregnancy (very vascular & increase blood vol.)
- Coagulopathy
How 2 meds can we use to stop a nose bleed?
Afrin & Phenylephrine
What does an NPA resemble?
- shortened tracheal tube/ETT
NPA design
What is the purpose of the flange on the NPA?
- located on the outer edge to prevent complete passage through nasal cavity
Which is more stimulating: OPA or NPA?
OPA
* NPA less irritating when they are waking up - they may just feel a little nasal pressure
NPA design:
how is an NPA sized?
in outer diameter in French Scale
* 10F - 36F
How is an NPA removed?
have pt take a deep breath & cough - pull it out
NPA Insertion
How do we size for a NPA?
correct size important
* bony manidble or nostril to the external auditory meatus
NPA insertion:
after insertion, where is it located?
LUBRICATE
* don’t be forceful - try other nare
* will be located ~10mm above epiglottis
What are the 6 complications of OPAs & NPAs?
- airway obstruction (incorrect placement - OPA)
- ulceration of nose or tongue
- dental/oral damage
- laryngospasm
- latex allergy (older NPAs - green in color)
- Retention/swallowing - size matters!
OPA & NPA complications
What causes airway obstruction w/ the OPA?
- not seated well (in b/w tongue & back of soft palate)
– pt de-satting, not getting Vt - the OPA will protrude if not seated well
OPA/NPA complications
What causes ulceration of nose/tongue?
- if they are left in for too long
- prone/lateral position causing pressure & ulceration
OPA/NPA complications
what is an alternative to an OPA that we can use in prone pts?
4x4 gauze roll as a soft bite block
OPA/NPA complications
What causes a laryngospasm?
- inadequately anesthetized patient
- ensure they are deep before placement
Who created supraglottic airways?
Dr. Archie Brain
What is the defintion of a supraglottic airway?
- intermediate bridge b/w face mask & endotracheal tube
- less invasive
- can be used w/ spont. ventilation or PPV
What are the differences b/w the 2 generations of supraglottic airways?
- 1st gen: don’t have a gastric lumen (no place to put gastric tube)
- 2nd gen: allows you to place a gastric tube down
LMA classic
how is it shaped?
- like a tracheal tube proximally
- elliptical mask distally
Where does the LMA classic sit?
- in the hypopharynx & surrounds the supraglottic structure
Describe the cuff on an LMA classic:
What types of LMA classics do they make?
- inflatable cuff
- latex free, reusable, disposable
Is the cuff empty when we insert the LMA classic?
No, helps to have a little bit of air in it
* as you seat it and get it in place then you inflate the cuff
Is the LMA classic 1 MRI compatible?
No, it has a metal spring
* if the LMA has a plastic spring then it can go in MRI
What size LMA will a neonate/infant up to 5kg get?
1
What size LMA will an infant b/w 5-10kg get?
1.5
What size LMA will an infant/child b/w 10-20kg get?
2
What size LMA will children b/w 20-30kg get?
2.5
What size LMA will children b/w 30-50kg get?
3
What size LMA will adults b/w 50-70kg get?
4
What size LMA will adults b/w 70-100kg get?
5
What size LMA will adults >100 kg get?
6
What are the only 2 1/2 sizes of LMA?
1.5: infant b/w 5-10kg
2.5: children b/w 20-30kg
Should we have other sizes of LMA available when inserting?
YES - size up and down 1!!
Incorrect sizing of LMA
What happens if an LMA is too small?
gas leaks during positive pressure
* not forming seal against glottis
* not passing enough gas or adequate vol. to pt
Incorrect sizing of LMA
What happens if an LMA is too large?
- won’t seat over glottis
- greater incidence of sore throat - could be hours later or next day
-
possible pressure on lingual, hypoglossal, and recurrent laryngeal nerves
– deflate, take it out, size down
Incorrect sizing of LMA
how will we be able to tell if it is too big?
- it will protude out of the mouth
What is the process for inserting an LMA?
- well lubricated;cuff mostly down
– avoid too much lube: won’t seat well - held like pencil
- upward against the hard palate
- follows the posterior pharyngeal wall
- smooth motion
- should feel it curve down in the airway and come to a stop
LMA insertion
What will you see/feel when the balloon(cuff) is inflated on an LMA?
- the neck will bulge and LMA may “rise” up slightly
LMA Insertion
What can we do with a difficult placement of an LMA?
- jaw lift
- pull tongue forward
- slightly inflate balloon
- may change to diff. technique
What is the LMA unique?
- single use, disposable
- made of PVC
- stiffer & cuff less compliant vs LMA classic (cuff less flimsy as cuff on LMA classic)
- insertion same as LMA classic
What is the LMA proseal?
- wire reinforced, shorter than LMA classic
- is a 2nd generation LMA
- gastric access w/ OGT
– when seated right - hole points to esophagus
– requires right size and that it is seated appropriately for gastric tube to go in right hole
What is the IGEL LMA?
- medical grade thermoplastic elastomer
- has a gastric channel
- has a conduit for intubation
- NO CUFF
What does the IGEL LMA provide a seal of?
- noninflatable, anatomical seal of the pharyngeal, laryngeal, & perilaryngeal structures
- PROTECTS AIRWAY BETTER THAN LMAs
Insertion of IGEL LMA:
- inserted the same way as LMA
- adequate lubrication!
- everything covering the airway - risk of aspiration decreased
– cuff is blocking off esophagus
What are the advantages of LMAs? (5)
- ease & speed of placement
- improved hemodynamic stability
- reduced anesthetic requirement - don’t have to be paralyze or have a lot of gas (can do w/ just prop)
- no muscle relaxtion needed
- avoidance of some of the risks of tracheal intubation (still @ risk of coughing and sore throat)
– lower risk w/ appropriately size LMA
What are 3 disadvantages of LMAs?
- smaller seal pressures than ETTs (increased risk of inadequate ventilation esp. w/ high airway pressures)
- no protection from laryngospasm (not through the cords)
- little protection from gastric regurgitation and aspiration (1st gen)
What LMA provides the best protection against gastric regurgitation & aspiration?
- IGEL - gastric opening & blocks off esophagus
- 2nd generation LMAs - gastric opening
What is the Shikani Optical Stylet?
- stainless steel, lighted stylet
- malleable distal tip
- uses an eye piece
- has O2 port for insufflation
How is the Shikani optical stylet inserted?
neutral position
* inserted midline
* advanced into trachea w/ light pressure keeping tip anterior at all times
* in peds & adult sizes
The Shikani Optical Stylet can be used as a ________ ________.
This allows you to verify what?
- light wand
- verifies ETT placement, or placement of DLT
4 Advantages to Optical Stylet:
- Easy to use for routine & difficult intubations
- trachea visualized, lower risk of esophageal intubation
- decreased incidence of sore throat (less trauma)
- less C-spine movemement over conventional DL
3 Disadvantages to Optical Stylet
- longer intubation time (familiarity)
- cannot be used w/ nasal intubations
- cannot be adjust into precise directions like traditional malleable stylet (only distal tip)
What are the 4 types of video laryngoscopes we talked about in class?
- Glidescope
- Co-pilot
- King
- McGrath
What are the 6 advantages to Video Laryngoscope?
- magnified anatomy
- some scopes have curved/straight blades to mimic laryngoscopes
- operator & assistant can see
- decreased c-spine movemement (less head/neck adjustment)
- furhter distance from infections pts (less transmission)
- demonstrates correct technique in legal cases
3 limitations to Video laryngoscopes
- requires video system (needs batteries/charged)
- portability varies
- can still fail and have difficulties
What are the 3 strongest predictors of failure w/ a VL?
- altered neck anatomy w/ presence of surgical scar
- radiation changes
- mass (oral, face, neck)
Complications of Laryngoscopy
Dental Injury: what are the most likely damaged?
What do tooth protectors do?
- upper incisors - restored or weakened teeth
- tooth protectors: placed on upper teeth in DL
– protect from blade causing direct surface damage
– does not gurantee safety from dental trauma
– mostly serve as a reminder to be vigilant
Complications of Laryngoscopy
What causes Cervical spinal cord injury?
- aggressive head positioning
- ex: meemaw w/ poor ROM
- assess in pre-op & document!!
Complications of Laryngoscopy: Cervical spinal cord injury
What is manual in-line stabilization?
- removal of the c-collar by the surgeon
- and they hold in-line stabilization while you intubate
- DOCUMENT the surgeon did it
- better than c-collar during DL
- use GLIDESCOPE or FIBER OPTIC!
Complications of Laryngoscopy
Damage to other structures: what causes abrasions/hematomas?
- dry mouth
Complications of Laryngoscopy
Damage to other structures: what can cause lingual &/or hypoglossal nerve injury?
when placing blade - hit soft tissue
* go in slowly & recognize structures
Complications of Laryngoscopy
Damage to other structures: what can cause arytenoid subluxation?
- hitting the arytenoids w/ the blade
- go slow
Complications of Laryngoscopy
Damage to other structures: what do we need to be cautious of w/ Hx of anterior TMJ dislocation?
do not force the mouth open
Complications of Laryngoscopy
What foreign bodies can be swallowed/aspirated?
What do we have to do?
- light bulbs
- teeth
- go to x-ray, CT, endoscopy, bronch
Tracheal Tubes Genreal Principles
What changes the resistance in a breathing system?
- ID of the tube: most important factor in determining resistance to gas flow in the ETT
- tube length: shorter tube (less resistance), longer tubes = increased resistance
- configuration changes (adding more connectors, turns = more resistance)
- corrugation
What are the 10 Manufacturing Requirements for Tracheal Tubes?
- low cost
- lack of tissue toxicity
- easy sterilization (unless disposable)
- non-flammability
- smooth & non-porous surface to prevent secretion build-up, allow passage of suction cath or bronch & prevent trauma
- sufficient body to maintain its shape
- sufficient wall strength
- conforms to pt anatomy
- lack of reaction w/ anesthetic agents & lubricants
- latex-free
Tracheal tube Design
How are the walls designed and what does this decrease?
- the internal & external walls are circular
- decreases kinking
Tracheal Tube Design
Where could an ETT be shortened?
- machine end
- decreases resistance
Tracheal tube Design
How is the pt end of the ETT?
- slanted bevel - helps view larynx
Tracheal Tube Design
What is the purpose of the murphy eye?
- provides an alternate pathway for gas flow if the beveled end is occluded from secretions
Tracheal Tube Design
What are the 2 biggest problems w/ the murphy eye?
- Magill forceps can get locked into the murphy eye
- fiber optic scope can get kinked/caught in murphy eye
What is a RAE tube?
Ring-Adair-Elwin tube
* Right angle tube
* used to keep ETT out of surgeons way: head/neck surgeries
* increased tube diameter - increased distance from tip to curve (resistance)
How do you insert a RAE (Ring-Adair Elwin) tube?
- temp. straightened in insertion
- may not need stylet
- if you use one and straighten it out for placement - when you remove stylet it goes back to original shape
- easy to secure (oral flips down over chin and is taped)
What are the disadvantages to a RAE (right angle) tube?
- difficult to pass suction/scope
- increases airway resistance (bend in tube)
What are other names for an Armored Tube?
- reinforced
- anode
- spiral embedded tubes
What are the Advantages to an Armored tube?
- useful when tube is likely to be bent or compressed
– resistance to kinking & compression - head, neck, tracheal surgeries
– more durable
– surgeon will move it how they need it
– they will NOT lose your airway
What are the Disadvantages w/ Armored tubes?
- Need stylet or forceps to get tube down
- difficult w/ nasal intubation (could be done)
- contains stainless steel in the tube - metal spiral that spirals down entire tube
– reinforces it/keeps shape - cannot be shortened
- damaged when biting
- NOT MRI compatible
What is a laser-resistant tube?
- metallic or silicone and metal mixture
- probably not MRI compatible
- Reflects laser beams used in oral surgeries
– CO2, or KTP (potassium titanyl phosphate)
Laser-Resistant tubes
How are the cuffs?
double cuffs
fill w/ methylene blue crystals & saline solution
* the methylene blue crystals are already int here
Which cuff do we inflate first on a laser-resistant tube?
- distal first
- than proximal
- the point of them is so if one bursts - the surgeon sees methylene blue - but there is still one protecting the airway
Where are the tube markings on the tube and how are they read?
- on bevel side above cuff
- read from pt side to machine
What are the 6 safety standards that have to be marked on an ETT?
- word oral or nasal or oral/nasal
- tube size in ID in mm
- manufacturer name
- graduated markings in cm from pt end
- cautionary note - single use only if disposable
- radiopaque marker at pt end (see on x-ray)
What is the typical cuff pressure and volume?
- 18-25mmHg (8-10mL air)
Why do we need to monitor cuff pressure when giving N2O?
- causes cuff inflation/expansion
- can lead to mucosal necrosis if > 25mmHg pressure
What is a high-vol/low-pressure cuff?
- area of contact larger, does not displace tracheal walls
- pressure applied to trachea < mucosal perfusion pressure
- may not prevent fluid leakage past cuff or NGT/temp probes around cuff
What is a low-vol/high-pressure cuff?
- small contact area w/ trachea
- needs more pressure to get seal
- distends & deforms trachea into circular shape
- off the market b/c pressure on trachea > mucosal perfusion pressure = mucosal necrosis
Changes in cuff pressure
nitrous:
hypothermic cardiopulm bypass:
increased altitude:
coughing, straining, changes in muscle tone:
- nitrous: increased
- hypothermic cardiopulm bypass: decreased (cold-induced vasoconstriction & contraction of microvasc. on tracheal wall)
- increased altitude: increased (boyle’s law)
- coughing, straining, muscle tone: increased
