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Airway Management Flashcards

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1
Q

Why Secure Airway?

A

o All ax > resp depression, relaxation, +/- loss of airway reflexes > patient prone to UAO
o Admin O2, volatile ax, other gases
o PPV, OLV
o Protect airway from aspiration (no cuff 100% leak proof)
o Low resistance, low dead space route for GE
o +/- protection from exposure to inhalants

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2
Q

Downsides to ETT Intubation

A

o Potential for laryngeal, tracheal injury
o Improper use: inadvertent bronchial intubation, lrg amt of dead space if long tube
o Possible ^d mortality in cats? Not a good study > GP, cats not regularly intubated, only cats getting ETT systemically compromised

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3
Q

Endotracheal tubes

A
  • Impt factor in resistance, WOB - HP
  • Internal diameter = narrowest diameter of equipment added to patient, site of greatest resistance
    -Bypasses nasopharyngeal cavity, v anatomic dead space
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4
Q

Wall Thickness of ETT

A
  • Thicker walls = greater difference btw internal, outer diameters
  • Very thick walled tubes: effectively decrease internal airway diameter
  • Wall thickness to tube diameter greater in small tubes, increases resistance
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5
Q

What determines size of ETT that can be placed in patient?

A

Outer diameter

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6
Q

What is the potential consequence of a thin walled tube?

A

Prone to kinking, obstruction via external compression

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7
Q

Ideal length of ETT

A

Incisors to thoracic inlet

Long tube will increase mechanical dead space, should trim machine end
decreased length will decrease resistance

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8
Q

Why are translucent tubes preferred?

A

Visual inspection of blood, mucus, debris

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9
Q

ETT Materials

A

PVC, silicone, red rubber, metal, latex

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10
Q

Pros: PVC ETTs

A

Inexpensive, compatible with tissues
Stiff enough for intubation at room temp, soften at body temp
Less likely to kink than rubber tubes
Smooth inner surface
Transparent

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11
Q

Cons: PVC ETTs

A

Disposable

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12
Q

Pros: silicone ETT

A

Sterilized, reused

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13
Q

Cons: silicone ETT

A

More expensive

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14
Q

Pros: red rubber ETT

A

Cleaned, sterilized, reused

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15
Q

Con: red rubber tube

A

Not transparent
Harden, become sticky overtime
More easily clogged by dried secretions
Do not soften at body temp
Risk of latex allergy

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16
Q

What markings are required per ASTM?

A
  • “Nasal,” “oral” or “Nasal/oral”
  • ID: tube size, btw cuff and take off point of inflation tube for cuffed tubes, patient end for uncuffed
  • OD for ETT <6.0
  • Manufacturer
  • Length, graduated markings showing distance in cm from patient end to allow depth of tube to be determined and monitored
  • If disposable, single use only or do not reuse
  • Radiopaque marker
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17
Q

What does F29 on an ETT mean?

A

toxicity implants

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18
Q

True/False: there are no standards for veterinary ETTs

A

True - should minimally have ID/OD

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19
Q

How convert from French gauge/catheter scale?

A

Should reflect internal diameter of tube, often reflects outer diameter
mm = Fr/3.14

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20
Q

Why is there a radiopaque marker at the end?

A

Black marker adjacent/near pilot balloon that indicates tube depth (people) -> cannot see once pas arytenoids

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21
Q

Size of proximal machine connection in SA

A

15mm OD

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22
Q

Size of LA large metal type that fits Bivona insert

A

22mm (Drager end)

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23
Q

Size of LA silicone funnel type connector to LA wye piece

A

54mm OD

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24
Q

What is the purpose of pediatric adaptors?

A

Smaller internal diameter, help improve accuracy of side stream, tidal gas sampling in smaller patients

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25
Q

Murphy ETT

A

o Murphy eye: hole in tube opposite of bevel
o Alternative route for gas flow should beveled end become occluded
 Always on right side of tube
 +/- Second eye above the bevel

Can become occluded/things get stuck in eye: stylets, bougies, fiberoptic scopes, suction

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26
Q

What direction does the Murphy ETT bevel face?

A

o Bevel always faces LEFT when viewed from concave aspect, with angle of bevel = 30*

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27
Q

What is the size of the Magill curve on a Murphy ETT?

A

anatomic curvature ~140 +/- 20mm on PVC tubes
 At body temp or when placed in warm water, curve will soften so lose () angle

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28
Q

Magill ETT

A

o Similar to Murphy, but NO Murphy eye!
o Allows cuff to be placed closer to tip, s risk of inadvertent bronchial intubation

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29
Q

Cole ETT

A

thin portion in trachea, thicker portion occludes larynx
o Do not produce same degree of airway security
o Used for very small patients, patients with complete tracheal rings ie birds, turtles
o Resistance less than that of a comparable tube of constant lumen

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30
Q

Safe-Seal ETT

A

o Uncuffed, self-sealing ETT for veterinary market (no Murphy eye or inflatable cuff)
o Tube designed with series of flexible flanges at patient end of ETT that deform to contours of trachea . form seal against tracheal wall > eliminates need to inflate cuff
o Limited number of sizes
o Tube efficacy not evaluated

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31
Q

Cuffs

A

o Purpose: provide seal btw tube/trachea, center tube in trachea
Inflation tube + pilot balloon + inflation valve

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32
Q

Advantages of a cuff

A

 Improved accuracy of monitoring end-tidal gases, compliance, O2 consumption
 decreased risk aspiration
 Ability to use high inflation pressures, low FGFs
 Less OR pollution
 decreased fire risk
 Fewer tube changes
 decreased risk spread of infectious droplets vs uncuffed?

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33
Q

Low vol, high pressure cuff

A
  • Small diameter at rest, low residual volume
    -Requires high intracuff pressure to achieve seal with trachea
  • Does not bear consistent relationship to tracheal wall pressure
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34
Q

Low vol, high pressure cuff relationship to trachea

A

-Small area of contact with tracheal wall, distends/deforms trachea to circular shape
-Most of pressure inside cuff used to overcome poor compliance of cuff: cuff pressure~pressure created by elastic recoil of cuff
-Intracuff pressure doesn’t change when trachea contacted

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35
Q

Advantages low vol, high pressure cuff

A
  • Better visibility during intubation DT streamlined cuff
  • Better protection of aspiration
  • Usually reusable, less expensive
  • Humans: lower incidence of sore throat
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36
Q

Disadvantages low vol, high pressure cuff

A
  • More difficult to estimate tracheal wall pressure, likely well above mucosal perfusion pressure
  • Risk of ischemic damage to tracheal wall with prolonged use
  • Intracuff pressure, lateral pressure on tracheal wall increases sharply as increments of air added
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37
Q

Use of low vol, high pressure cuffs

A

 Impt to check for leaks approx 10’ after intubation: softening of cuff material at body temp, volume necessary for occlusion varies with muscle tone

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38
Q

High vol, low pressure cuffs

A

-Preferred: may help reduce tracheal damage from cuff overinflation
Pressure exerted by cuff similar to intracuff pressure
 Thin, compliant wall allows seal with trachea to be achieved w/o stretching tracheal wall
 Cuff inflated: first touches trachea at widest part of cuff, area becomes larger as cuff begins to inflate, cuff adapts itself to shape of tracheal surface
If cuff inflation continued, area in contact with cuff subject to increasing pressure > trachea distorted

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39
Q

High Vol, Low pressure cuff: variations during SpV

A

airway, cuff pressure negative during inspire, positive during expire

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40
Q

High vol, low pressure cuff: variations during CMV

A

airway pressure exceeds intracuff pressure, positive pressure will be applied to lower face of cuff  if cuff wall pliable, unable to resist pressure > will be deformed into cone shape as distal portion is compressed, proximal portion distended
* Air in cuff will be compressed until intracuff pressure = airway pressure

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41
Q

High vol, low pressure cuff: exhalation

A

intra cuff pressure will decrease until resting pressure is reached

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42
Q

High vol, low pressure cuff: advantages

A
  • As long as cuff wall not stretched, intracuff pressure closely approximates pressure on tracheal wall > possible to measure, regulate pressure exerted on tracheal mucosa
  • If used properly, risk of significant cuff-induced complications with prolonged use decreases
  • Easy to pass esoph stethoscopes, temp probes, etc around
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43
Q

High vol, low pressure cuff: disadvantages

A
  • Can obscure view of tube tip, larynx DT bulkier cuff, can be problematic in smaller patients
  • Cuff more likely to be torn
  • Greater likelihood that dislodged???
  • Humans: higher incidence of sore throat
  • May not fully protect against aspiration, even at cuff pressures as high as 60 cm H2O
    o Less leaking if no folds, CPAP, PEEP, PSV
  • WILL NOT PREVENT HIGH PRESSURES FROM BEING EXERTED ON TRACHEAL WALL
    o ANY CUFF CAN BE OVERFILLED, VOL/PRESSURE CAN DECREASE DURING USE
    o Ex: N2O will diffuse into cuff, added volume will increase pressure on tracheal mucosa
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44
Q

Other types of cuff

A

Foam Cuf
Lanz Cuff
Jorvet

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45
Q

Foam Cuff

A

expansion determines pressure on tracheal wall, more foam expansion less pressure, pressure inside cuff will follow approx airway pressure during vent cycle

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46
Q

How seal foam cuff

A

o To seal: open inflation tube to atmosphere, allow cuff to fill with air
o Ability to remove 2-3mL air from small cuff, 5-6mL from larger cuffs and maintain seal usually signifies cuff:tracheal wall pressure ratio will allow adequate mucosal perfusion

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47
Q

Lanz Cuff

A

-pressure-regulating valve, eliminates need to measure cuff pressure, effective in keeping lateral tracheal wall pressure low and preventing increases in cuff pressure DT N2O
o To seal: add air until seal achieved during peak inspiration

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48
Q

What is a Jorvet cuff?

A

The weird baffles

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49
Q

What is the typical pressure on the lateral tracheal wall at the end of expiration per DD?

A

25-34 cm H2O (20-30)
* If high peak inflation pressures, will need higher cuff pressure to prevent leaks (minimum occlusion pressure) –> increases risk tracheal injury

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50
Q

At what point will tracheal mucosa become slightly pale with visible, pulsatile arterioles?

A

30 cmH2O

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51
Q

What are factors that can change intracuff pressure?

A

–N2O: increase varies directly with partial pressure of N2O, permeability of cuff wall, time
o Slowed by heated humidification
–Pressures lower during hypothermic bypass
–Increased pressures seen with nearby surgical procedures, increases in altitude, diffusion of oxygen into cuff, changes in head position away from neutral, coughing, straining, changes in muscle tone
o Not seen with foam-filled cuffs

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52
Q

At what pressure is capillary flow impeded, leading to ischemia?

A

48cm H2O

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53
Q

Consequences of tracheal rupture?

A

Pneumothorax
Pneumediastinum
SQ emphysema

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54
Q

At what pressure is there increased risk of aspiration?

A

<25cm H2O, increased risk aspiration

55
Q

Three methods to check cuff pressure

A
  • Cuff monitor: high volume, low pressure cuffs - low pressure manometer attached to pilot balloon of cuff
  • Leak test: Inflate cuff with air, water, sponge until leak no longer audible when maintaining airway pressures of 20-30 cm H20
  • Modified human products/Tru-Cuff syringes
56
Q

Pilot Balloon

A

most have self-seal syringe activated system (spring loaded one way valve), some require clamp
 External diameter of pilot balloon line <2.5mm, attached to ETT at angle

57
Q

Combitube

A

 Emergent intubation in field setting with people
 No laryngoscope
 Place tube, inflate distal cuff -> if no CO2, inflate proximal cuff to protect airway, functions as LMA
 Described in dogs, not often used

58
Q

King Airway

A

 NOT A COMBITUBE
 Distal tube goes into esophagus
 No distal lumen
 Supraglottic airway device, ventilates like combitube

59
Q

Laser Resistant tubes: Hunker Tube

A

designed for jet ventilation – compatible with CO2, neodymium-yttrium aluminum garnet (Nd-YAG), argon laser, OD 3mm

60
Q

Laser Resistance Tubes: Laser Shield II tube

A

inner aluminum wrap, outer Teflon coating
* CO2, potassium-titanyl-phosphate (KTP) lasers
* Cuff not laser resistant, contains methylene blue

61
Q

Laser Resistance Tubes: Laser-Flex Tracheal Tube

A
  • Stainless steel with smooth plastic surface, matte finish to reflect beam
  • CO2, KTP lasers
  • Adult version: two PVC cuffs, PVC tip with Murphy eye
  • Fill cuffs with saline colored with methylene blue
  • Still, rough surface, difficult to intubate quickly (double cuff), large external diameter, less likely to reflect CO2 laser radiation than other tubes
62
Q

Laser Resistant Tube: Norton Tube

A
  • Reusable, flexible, spiral-wound metal tube with stainless steel connector and thick walls
  • Tube exterior: matte finish to  reflection of laser beam
  • CO2, KTP, Nd-YAG
  • Uncuffed, can be added
  • Disadvantages: coils not air-tight, angulation leads to large leak, rough outer surface, sharp edges – tissue damage, large external diameter, stiff, requires special ventilation techniques
63
Q

Laser Resistance Tubes: Bivona Fome-Cuf Laser Tube

A
  • Aluminum, silicone spiral with silicone covering
  • Self-inflating cuff: polyurethane foam sponge, use saline intraop
  • Inflation tube runs along exterior of tube, colored black so that position away when laser in use
  • Marketed for use with CO2, poorly resistant to all lasers
64
Q

Laser Resistant Tubes:  Lasertubus

A
  • White rubber, tube within a tube: if outer cuff (saline, water) perforated by laser, trachea still sealed by inner cuff (air)
  • High pressure cuff
  • Shaft above cuff covered by corrugated silver foil, which is covered by Merocel sponge that should be moistened before use
  • Argon, CO2, Nd-YAG
65
Q

Merocel Laser Guard

A

two-layered sheet of synthetic surgical sponge, adhesive-backed corrugated silver foil
o PVC, rubber tubes only
o When wet, sponge/reflective foil act like a heat sink  disperse argon, CO2, Nd-YAG, KTP laser beams

66
Q

If you don’t have a specialized tube for laser sx, now what?

A
  • Fill ETT balloon with water instead of saline
  • Cover with damp gauzes and KEEP MOIST
    (most in lasers section)
67
Q

Guarded/Armored tube

A

 Contain metal or nylon spiral wire covered by rubber, PVC, silicone to prevent kinking
 Useful in situations where tube likely to compressed, kink ie extreme flexion of head or compression of trachea
* Kinking: airway obstruction, d resistance
 Thicker OD, smaller ID: increased resistance to flow

68
Q

Advantages to guarded tube

A

less likely to kink if tube bent or head/neck flexed, may pass more easily over fiberscope

69
Q

Disadvantages to a guarded tube

A

NO MURPHY EYE

cannot be shortened, forceps or stylet sometimes needed for intubation, should not be resterilzed, elastic recoil force may increase tendency of accidental extubation

70
Q

Ring-Adair-Elwin Tube

A

 Preformed bend that may be temporarily straightened during intubation
 Cuffed, uncuffed; nasal, oral
 Used for head and neck surgery
 Diameter increased, -> length, distance from distal tip to curve also increased

71
Q

Ring-Adair-Elwin Tube PO vs Nasal parts

A
  • PO: external portion bent at an acute angle, rests on patient’s chin with connector over patient chest when in place
  • Nasal: opposite curve so that outer portion directed over patient’s forehead to reduce pressure on nares
72
Q

Laryngotomy tube

A

J at patient end to insert into tracheostomy site

73
Q

Flex Tubes

A

 Endoflex: anterior larynx in peopke, tube can flex at cuff
 Parker Flex-Tip Tube: hooded curved tapered tip with Murphy eyes on L, R, easier to advance over scope or intubating catheter

74
Q

Tubes with Extra Lumens

A

 Useful for respiratory gas sampling, suctioning, airway pressure monitoring, fluid/drug injection, jet ventilations
 Disadvantages: secretions, blood or moisture can obstruct extra lumen; sampling tube must be securely stabilized to minimize tension on tube, moisture can enter gas lumen, cause problems with gas monitor

75
Q

Nerve Integrity monitoring

A

 EMG reinforced tracheal tube
 Monitor RLN electromyogram (EMG) activity during sx
 Wire-reinforced, four stainless steel electrodes above cuff with electrodes connected to a monitor

76
Q

Complications during intubation

A

hematomas, contusions, puncture wounds, tracheal rupture, fractures, arytenoid cartilage dislocation, perforation of any structures in area

o Sore throat, hoarseness, upper airway edema, vocal cord dysfunction, ulcerations

o Neurological injuries: trigeminal, lingual, buccal, hypoglossal

77
Q

Confirmation of correct placement into trachea

A

o Most reliable methods: direct visualization of tube passing btw vocal cords, capnometry, auscultation: both sides of chest (gurgling sounds – esoph), breathing system auscultation, fiberoptic visualization, pressure/flow-volume loops
 ASA standard: confirm correct placement into trachea with capnometry
 False negative: severe bronchospasm, cardiac arrest, no pulmonary blood flow (PE, one way obstruction in tracheal tube)

78
Q

Other less reliable methods

A

feel of reservoir bag, chest wall motion, epigastric distention, moisture accumulation in trachea, gastric contents in tracheal tube, CXR, oxygenation, palpation, cuff inflation

79
Q

Challenges of using chest wall movement to confirm placement into trachea

A

following conditions could stimulate tracheal intubation during esoph intubation: patients with low lung volume, obese patients, low chest wall compliance, abdominal resp

80
Q

Strategies to troubleshoot leaking cuff

A

o Use pharyngeal packing to control leak, increase FGF to compensate for leak
o Fill cuff with mixture of lidocaine, saline or use saline infusion
o Continuous gas infusion into inflation tube
o Supraglottic device
o Replace ETT

81
Q

Causes of Obstructions

A

Biting
kinking
materials in tube lumen (secretions, gastric contents, blood, etc)
occlusion of spiral end tube (NO MURPHY EYE) cuff herniation/bevel displacement
external compression or displacement (aorta, enlarged thyroid, etc)
defective connector
Change in body position

82
Q

Dx: obstructions

A

 decreased compliance or expiratory flow
 increase in difference btw peak and plateau pressure with VCV
 decrease VT with PCV
 Wheezing
 PV loops
 Spontaneous ventilation: paradoxical chest movements
 Capnograph: increased slope phase III, large  angle – “shark fin”

83
Q

Consequences of obstructions

A

o High negative intrathoracic pressure  NCPE
o Permits inhalation, prevents exhalation (ball-valve obstruction): circulatory collapse, barotrauma

84
Q

Stylets

A

 Designed to fit inside ETT, change shape of ETT to facilitate intubation
 Check patency of ETT
 Means to limit depth stylet inserted into ETT
 Enough malleability to shape can change easily, will yield if pressed against soft tissues, rigid enough to maintain shape

85
Q

Bougies

A

 Soft, flexible, cannot really shape to fit ETT – long, straight
 Fabricated from polyester base with resin coating
 Reusable

86
Q

Cook Airway Exchange Catheters

A

 More flexible, longer than a bougie
 Hollow -> proximal connections allow admin of O2, jet ventilation, connection to ETCO2 or suctioning
 Must be long enough so that tube can be completely removed without catheter pulled
into trachea, stiff enough so won’t kink

87
Q

Laryngoscopes

A
  • Aid tracheal intubation, oropharyngeal evaluation/airway exam
  • Plastic with fixed blade, stainless steel with interchangeable blades of different sizes
  • Handle with lighted blade - No clear advantage over lighting system
88
Q

Fiber Optic Laryngoscope Blade

A

 Bulb is in blade handle, blade has optical fiber -> communicate
* Halogen lamp bulb
 Can be more reliable, less likely to have bulb fall off inside patient
 ASTM standards: green mark

89
Q

Bulb in Blade

A

 Electrical (metallic) contact, has to be clean and in good working order
 Overtime can erode, less consistent than fiber optic

90
Q

Video laryngoscopy

A

usually used for teaching, small direct video laryngoscopy with bronchoscope

91
Q

Other laryngoscope modifications

A

changes for very small, very large patients; magnification; cheek spreaders for small ruminants or rodents

92
Q

Blades

A

000-5
o Tongue = main shaft, base attaches to handle
o Tip = beak
o Flange = projects off side of tongue, connected by web – guide instrumentation, deflect tissues from line of vision
o Blade flange typically on right side of blade when viewing from top
 Optimal laryngeal visualization when intubating in dorsal, laryngoscope held in L hand with blade downward (inverted) and tube in R hand with concave aspect pointing up

93
Q

Complications of Direct Laryngoscopy

A

dental injury
cervical spinal cord injury if aggressive head positioning
hematoma/lacerations to any oral/airway structures
shock/burn if light left on
swallowing/aspirating FB (loose light)

94
Q

Laryngeal Mask Airways

A

o Human products, adapted for veterinary use
o Optimized specifically for orolaryngeal/pharyngeal anatomy of humans  may not conform well to varied anatomy, patient size, species, breeds of veterinary patients
o Inappropriate SGAD +/- patient selection may lead to placement difficulties/failures, damage to tissues of oropharyngeal region, +/- improper patency of airway

95
Q

Advantages of LMAs

A

o Do not require laryngoscope, do not enter larynx or trachea
 Possibly faster, easier to place in some species
 +/- less ax required to place
o Tube connected to elliptical mask with inflatable outer edge  when placed/inflated correctly, form seal around glottis
 Can PPV
 Not assoc with greater leakage ax gases

96
Q

Wiederstein and Moens 2008 (VAA):

A

clinically optimal position, seal around larynx adequate for manual PIP 10cmH2O 63.3% dogs, suboptimal positioning/inability to ventil in 36.7%

97
Q

V-gels

A

veterinary specific product for cats, rabbits (and now dogs)

98
Q

Why perform OLV

A
  • Thoracoscopy, control of contamination, hemorrhage, unilateral pathology
99
Q

Three MOA for OLV

A
  1. double lumen tube
  2. Bronchial blocker
  3. Standard but long ETT
100
Q

What are three DLT options?

A

Robertshaw, Carlens, White

101
Q

Double Lumen Tubes

A

Two single lumen tubes bonded together, angled tip to facilitate placement into bronchus

Two elliptical cuffs: trachea, bronchus (different colors)

Allows independent ventilation of each lung or together without moving, replacing tube

Requires disconnection/reconnection, appropriate adapter for task

102
Q

R vs L sided tubes in dogs?

A

placement uncertainty in dogs -> R cranial LL branches more proximally than in people, failure of complete hemithorax isolation

103
Q

How are DLT sized?

A

French scale: 26-41 Fr

decreases lumen size -> increases resistance to breathing, overcome by PPV

104
Q

Size limitations on use of DLT

A

Designed for humans so 5-20kg

105
Q

Problems with the Carlens, White Tubes?

A

carinal hook designed to aid in proper placement, prevent movement after positioning
 May hinder ETT placement
 Ensure does not catch on tissues, structures

106
Q

Which is the DLT of choice for canine patients?

A

o L ROBERTSHAW

107
Q

How confirm correct placement of DLT

A

endoscopy – direct visualization, thorascopic-assisted technique, lung sounds bilaterally following ventilation of both sides
 Blind: high failure rate
 Prone to movement, can prolapse into trachea -> airway obstruction

108
Q

Bronchial Blockers

A

Very adaptable over wider range patient sizes, not as anatomically specific

Long catheters tipped with cuff/balloon
 Usually blue to differentiate from ETTs
o Used coaxially with standard ETT, swivel adapter – ports for passing blocker, scope, etc

Length of bronchial blocker limited, may not be sufficiently long for larger patients

109
Q

Placement of bronchial blockers

A

fiber optic assisted direct visualization for correct placement
 Used to isolate single lung lobe in addition to entire hemithorax
 Once in correct place via direct manipulation of proximal portion or guide wire into bronchus, bronchial blocker channel opened  lung collapses
Open channel: CPAP, oxygen insufflation, suction
Right bronchus challenging, proximal branching of cranial lobe

110
Q

Downsides of bronchial blockers?

A

May not be sufficiently long enough for larger patients

Independent lung ventilation not possible without withdrawing, replacing in contralateral bronchus

Prolapse of bronchial blocker into trachea = complete airway obstruction
 Placed proximally in bronchus +/- tube/bronchial blocker withdrawn inadvertently when moving or manipulating the patient

111
Q

What can be used as a bronchial blocker?

A

Any Balloon catheter (Fogarty, Foley)

112
Q

Standard but long ETT for OLV

A

o Least desirable: less direct control for making changes in non-intubated lung
o No specialized equipment required
o Easy to perform

113
Q

Risks of OLV

A

Pulmonary reexpansion injury
VQ mismatch
anatomical concerns/difficult placement

114
Q

Nasotracheal intubation

A

o Procedures involving oral cavity, sedated conscious animals that will not tolerate ETT but require O2, induction of GA in foals/calves
o Performed in many species: reported in foals, calves, horses, camelids, rabbits, kangaroo

115
Q

Tube used for NTT

A

minimal curvature/straight, thin walled for larger ID, LV/HP cuff better for passage bc less bulky, HV/LP cuff better for longer periods of ax
 Will be smaller than orotracheal tube, increased resistance

116
Q

How NTT

A

o Extend head and neck to facilitate passage, lube ventral nasal meatus
o Confirmation by inflated “bulb syringe,” auscultation of lung fields, capnography
o Careful extubation to avoid nasal hemorrhage if shake head
 Main complication: nasal hemorrhage

117
Q

Wire Guided Tube Techniques

A

o Direct visualization of laryngeal opening not possible or obscured
o OTW technique or the Campoy feed off
o Blunt end to avoid tracheal damage

118
Q

Tube Exchangers

A

o Failing cuff, placement of sterile tube, alternative tube size/length required
o Depending on size of patient, standard commercially available human tube exchangers can be used
o Be sure to dc inhalant ax if using prior to exchange, have injectable boluses ready if needed

119
Q

Endoscopic Guided

A

o Abnormal anatomy, dz processes involving pharynx, head, neck or if challenging to intubate with direct laryngoscopy
o Flexible or rigid
o Placed within ETT to guide intubation directly or passed orally beside ETT to guide correct placement visually
o Also used for nasotracheal intubation
 Horses/other LA with abnormal oropharyngeal, laryngeal +/- nasal anatomy where direct laryngoscopy impossible

120
Q

Retrograde Intubation

A

o When direct visualization of glottis impossible
o Evaluated in camelids, mice
o Needle introduced through ventral neck btw tracheal rings, wire passed rostrally into larynx/pharynx until can be used as OTW technique to pass ETT
 Ensure cuff caudal to needle puncture site to avoid forcing gas subcutaneously or into mediastinum during PPV

121
Q

Complications of retrograde intubation

A

SQ emphysema, pneumothorax

122
Q

Tracheostomy

A

o Surgeries involving oropharynx, traditional intubation impossible, patient requires tracheostomy post-operatively, emergent upper airway obstruction
o Simple to intubate through tracheostomy
 Can be difficult in patients with very small-diameter tracheas, those with very thickened/calcified tracheal rings

123
Q

Trach Tubes

A

generally shorter with acute angle, standard 15mm connection adapter, smaller sizes often do not have a cuff

o If not cleaned regularly, can become obstructed by mucus that dries within lumen

124
Q

Risks, complications of tracheostomies

A

NOT TOLERATED WELL IN CATS

infection, granulomas, tracheal stricture, cartilage damage, hemorrhage, pneumothorax, subcutaneous edema, tracheocutaneous/tracheoesophageal fistula, aspiration, dysphagia, tracheal malacia

125
Q

Tracheostomy Technique

A

 Ventral neck
 Ventral midline cutaneous incision 2-3cm cd to cricoid cartilage
 Blunt dissection: separate sternohyoid m along fascial plane until trachea visualized
 Transverse tracheotomy incision through annular ligament btw tracheal rings, do not incise >50% circumference
 Stay sutures cr, cd to incision  traction  insert trach tube

126
Q

Rhino Technique

A

o Similar to traditional tracheostomy
o Less surgical manipulation, no difference according to literature
 Higher risk of not cannulating trachea, causing SQ emphysema, fracturing tracheal rings
 Not faster (Pardo et al 2019)
o Modified Seldinger Technique: place J wire facing lungs, feed multiple dilators over J wire increase size of entry into trachea

127
Q

Lateral Pharyngotomy

A

o Alternative to tracheostomy for sx procedures of mandible, maxilla, oral cavity
o Slightly less invasive than tracheostomy
o Skin incision near angle of the mandible  adaptor removed  machine end of tube pulled through the pharynx/skin incision  reconnected
o Dentistry, similar to E tube placement

128
Q

Why deliver oxygen

A

o PaO2 and promote delivery of oxygen to tissues
o Room air, PaO2 <80mmHg indicate potential for hypoxemia, <60mmHg indicates need for supplemental oxygen
o PaO2 ~ 500 x FIO2 if no major abnormalities
o Supplemental oxygen can correct hypoxemia with diffusion, VQ mismatch or hypoventilation, but may not significantly improve shunt
o Monitor improvement by patient clinical response, measuring FIO2, monitoring PaO2, SaO2, SpO2

129
Q

Methods for oxygen delivery

A

o Mask Delivery: before induction, patients in resp distress
o Nasal Insufflation: delivery of oxygen at relatively high flow rates
o Tracheal Insufflation: Patients suffering from upper airway obstruction
o Oxygen Cages: small animals, regulate oxygen, humidity, temperature, and eliminate CO2

130
Q

Flow By Oxygen

A

~FiO2 25-40%, FR 0.5-5L/min

131
Q

Face Mask

A

~FiO2 35-60%, FR 2-8L/min

132
Q

Nasal Insufflation

A

~FiO2 30-70%, FR 100-150mL/kg/min

133
Q

Tracheal Insufflation

A

~FiO2 40-60%, FR 50mL/kg/min

134
Q

Oxygen Cages

A

~FiO2 25-50%, FR variable

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