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BOARD REVIEW > Respiratory > Flashcards

Respiratory Flashcards

1
Q

Which muscles tense and relax the vocal cords?

A

Tense and relax:
Cricothyroid: “Cords Tense:
Thyroarytenoid: “They relax”

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2
Q

Which muscles abduct and adduct the vocal cords?

A

Abduct and adduct:
Posterior Cricoarytenoid: “Please come apart”
Lateral cricoarytenoid: “Let’s close airway”

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3
Q

Describe the sensory innervation of the upper airway

A

V1 (opthalamic) = nares & anterior 1/3 of tongue
V2 (maxillary) = turbinates & septum
V3 (mandibular) = posterior 2/3 of tongue

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4
Q

Describe the glossopharyngeal sensory innervation of the upper airway (5)

A
  • posterior 1/3 of tongue
  • soft palate
  • oropharynx
  • vallecula
  • anterior side of epiglottis
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5
Q

Describe the sensory and motor innervation (2 branches) of the superior laryngeal nerve innervation on the upper airway

A

Internal branch = posterior side of the epiglottis > to level of the vocal cords

External branch = 0 sensory function (motor innervation to cricothyroid muscle)

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6
Q

Describe the recurrent laryngeal nerve innervation of the upper airway

A

Below the vocal cords > to trachea

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7
Q

How does RLN injury affect the integrity of the airway?

A

Unilateral = no respiratory distress

Bilateral =

  • acute = respiratory distress (unopposed action of cricothyroid muscles)
  • chronic = no respiratory disress
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8
Q

How does the SLN injury affect the integrity of the airway?

A

Unilateral = no respiratory distress

Bilateral = hoarseness/no respiratory distress

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9
Q

Name 3 airway blocks, and identify the key landmarks for each one

A
  1. Glossopharyngeal nerve block: palatoglossal arch at the anterior tonsillar pillar
  2. SLN: greater cornu of hyoid
  3. Transtracheal nerve block: cricothyroid membrane
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10
Q

What are the three paired cartilages of the larynx?

A
  1. Corniculate
  2. Arytenoid
  3. Cuneiform
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11
Q

What are the three unpaired cartilages of the larynx?

A
  1. Epiglottis
  2. Thyroid
  3. Cricoid
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12
Q

What is the treatment of laryngospasm?

A
  • 100% FIO2
  • remove noxious stimuli
  • deepen anesthesia
  • CPAP 15-20 cm H2O
  • open the airway (head extension, chin lift)
  • Larson’s maneuver
  • Succinylcholine
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13
Q

Succinylcholine in children for laryngospasm

A
  • MUST receive atropine (0.02 mg/kg) with succs
  • no IV access: submental administration will produce the fastest onset
  • If no IV and pt cannot have succs, roc is the only NMB that can also be given IV
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14
Q

Describe the respiratory muscles during inspiration

A
  • the diaphragm and external intercostals contract
  • the diaphragm increases the superior-inferior dimension of the chest
  • the external intercostals increase the anterior-posterior diameter
  • accessory muscles include the sternocleidomastoid and scalene muscles
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15
Q

Describe the respiratory muscles during expiration

A
  • expiration is passive; driven by the recoil of the chest wall (ACTIVE process in COPD pt’s)
  • active exhalation is carried out by the abd muscles
  • internal intercostals serve a secondary role in active exhalation
  • forced exhalation is required to cough and clear airway secretions
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16
Q

What is the difference btw minute ventilation and alveolar ventilation?

A

Minute ventilation (Ve): the amount of air in a single breath multiplied by the number of breaths per minute

Alveolar ventilation (VA): only measures the fraction of Ve that is available for gas exchange; AKA it removes anatomic dead space from the Ve equation

  • VA is directly proportional to CO2 production
  • VA is indirectly proportional to PaCO2
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17
Q

Name the 4 types of the dead space

A
  1. Anatomic Vd: air confined to the conducting airways
  2. Alveolar Vd: alveoli that are ventilated but not perfused
  3. Physiologic Vd: anatomic + alveolar
  4. Apparatus Vd: added by equipment
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18
Q

List examples of the 4 types of deadspace

A
  1. Anatomic: nose/mouth > terminal bronchioles
  2. Alveolar: reduced pulmonary blood flow ( decreased CO)
  3. Physiologic: anything that increases anatomic or alveolar Vd
  4. Apparatus: Facemask, HME, limb of circle is incompetent valve present
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19
Q

What does the alveolar complicance curve tell you?

A

Alveolar ventilation

Alveolar ventilation is a function of alveolar size and its position on the alveolar compliance curve

  • the best ventilated alveoli are the most compliant (steep slope of the curve)
  • the poorest ventilated alveoli are the least compliant (flat portion of the curve)
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20
Q

What does the V/Q ratio represent?

A 
V/Q ratio if the ratio of ventilation to perfusion 
(Ve / cardiac output)
- normal Ve = 4L/min
- normal CO = 5L/min
- normal V/Q ratio = 0.8
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21
Q

Describe V/Q mismatch

A
  • dead space = V/Q: infinity (>0.8)
  • shunt: V/Q: 0 (<0.8)
  • if the number is larger than 0.8, it moves toward dead space
  • if the number is smaller than 0.8, it moves towards shunt
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22
Q

West Lung Zone I

A
  • PA > Pa > Pv
  • dead space
  • ventilation without perfusion
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23
Q

West Lung Zone II

A
  • Pa > PA> Pv
  • waterfall
  • normal physiology
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24
Q

West Lung Zone III

A
  • Pa > Pv > PA
  • Shunt
  • perfusion without ventilation
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25
Q

Zone IV

A
  • Pa > Pist > Pv > PA

- pressure in interstitial space impairs ventilation and perfusion

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26
Q

Recite the alveolar gas equation

A

The alveolar gas equation tells us that hypoventilation can cause can hypercarbia and hypoxemia, but does nothing to reverse hypercarbia

PAO2 = FiO2 x (Pb - PH20) - (PaCO2 / RQ)

  • Pb = atmospheric pressure
  • PH20 = 47 mmHg
  • RQ = respiratory quotient = 0.8

Alveolar oxygen in the healthy adult patient breathing room air at sea level is ~ 105.98 mmHg

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27
Q

What is the A-a gradient (definition and value) and what factors increase it?

A

The A-a gradient is the difference btw alveolar oxygen (PAO2) and arterial oxygen (PaO2)

  • it helps us diagnose the cause of hypoxemia by quantifying the amount of venous admixture
  • it is normally 5 - 15 mmHg
  • it is increased by high FiO2, aging, vasodilators, right-to-left shunting and diffusion limitation
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28
Q

List the 5 causes of hypoxemia

A

Normal A-a gradient:

  1. reduced FiO2: not enough O2 in inspired gas
  2. hypoventilation: inadequate air transfer in and out of the lungs
  3. diffusion limitation: capillary thickening hinders O2 diffusion
  4. V/Q mismatch: poor matching of V and Q
  5. Shunt: pulmonary blood bypasses alveoli
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29
Q

Which cause of hypoxemia is NOT reversed with supplemental O2?

A

Shunt: there is no way for O2 to access the pulmonary capillary. All other causes allow O2 to transfer btw the alveolus and the pulmonary capillary

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30
Q

Inspiratory Reserve Volume

A

3000

Amount of gas that can be forcefully inhaled after a tidal volume

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31
Q

Tidal Volume

A

500

Amount of gas that enters and exits the lungs during tidal breathing

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32
Q

Expiratory Reserve Volume

A

1100

Volume of gas that can be forcibly exhaled after a tidal volume

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33
Q

Residual Volume

A

1200

Volume of gas that remains in the lungs after complete exhalation; cannot be exhaled from the lungs

Volume of alveolar gas that serves as O2 reservoir during apnea

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34
Q

Closing Volume

A

Variable

The volume above residual volume where the small airways begin to close

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35
Q

Total Lung Capacity

A

5800

IRV + TV + ERV + RV

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36
Q

Vital Capacity

A

4500

IRV + TV + ERV

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37
Q

Inspiratory Capacity

A

3500

IRV + TV

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38
Q

Functional Residual Capacity

A

2300

RV + ERV

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39
Q

Closing Capacity

A

Variable

RV + CV

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40
Q

What factors increase FRC and what factors decrease FRC?

A

Because it contains RV, FRC cannot be measured by conventional spirometry

Decreased FRC: tend to reduce outward lung expansion or reduce lung compliance
- when FRC is reduced, intrapulmonary shunt (zone III) increases. PEEP acts to restore FRC by reducing zone III

Increased FRC: COPD or any condition that causes air trapping increases FRC

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41
Q

What tests can measure FRC?

A

FRC is measured indirectly by nitrogen washout, helium wash in, or body plethysmography

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42
Q

What is closing volume and what increases it?

A

Closing volume is the point at which dynamic compression of the airways begins; AKA the volume above residual volume where the small airways begin to close during expiration

CLOSE-P

C: COPD
L: Left ventricular failure
O: Obesity
S: Supine position
E: Extreme age
P: Pregnancy
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43
Q

State the equation and normal value for oxygen carrying capacity

A

CaO2:

  • how much O2 is carried in the blood
  • CaO2 = (1.34 x Hgb x SaO2) + (PaO2 x 0.003)
  • normal = 20 mL O2/dL
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44
Q

State the equation and normal value for oxygen delivery

A

DO2

  • how much O2 is delivered to the tissues
  • DO2 = CaO2 x CO x 10
  • Normal = 1,000 mL O2/min
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45
Q

What factors cause a left shift in the oxyhgb dissociation curve? (8)

A

Left shift = increased affinity

Left = lungs love

  1. Decreased temp
  2. Decreased 2,3-DPG
  3. Decreased CO2
  4. Decrease [H+]
  5. Increased pH (alkalosis)
  6. HgbMet
  7. HgbCO
  8. Hgb F
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46
Q

What factors cause a right shift in the oxyhgb dissociation curve? (5)

A

Right shift = decreased affinity

Right = release

  1. Increased temp
  2. Increased 2,3-DPG
  3. Increased CO2
  4. Increased [H+]
  5. Decreased pH
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47
Q

What is CO2 and how is CO2 transported in the blood?

A

CO2 is the primary by-product of aerobic metabolism. Venous blood transports it to the lungs, where it is excreted into the atmosphere

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48
Q

Describe the Bohr effect

A
  • the Bohr effect describes O2 carriage
  • it says that increased CO2 and decreased pH cause erythrocyte to release O2
  • conceptually, it’s the cell’s way of asking hgb to release O2 to support aerobic metabolism
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49
Q

Describe the Haldane effect

A
  • the Haldane describes CO2 carriage
  • it says increased O2 causes the erythrocyte to release CO2 (occurs in the lungs)
  • AKA the Haldane effect states that deoxygenated Hgb is able to carry more CO2 (in venous blood)
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50
Q

List the 3 primary causes of hypercapnia and provide examples of each

A
  1. increased CO2 production (sepsis, overfeeding, MH, intense shivering, prolonged seizure activity, thyroid storm, burns)
  2. Decreased CO2 elimination (airway obstruction, increased dead space, increased Vd/Vt, ARDS, COPD, respiratory center depression, drug overdose, inadequate NMB reversal)
  3. Rebreathing (incompetent one-way valve, exhausted soda lime)
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51
Q

Describe the 4 areas in the respiratory center

A

Medullary centers:

  1. Dorsal Respiratory Center: active during inspiration (respiratory pacemaker)
  2. Ventral Respiratory Center: active during expiration

Pontine Centers:

  1. Pneumotaxic center (upper pons): inhibits the DRC
  2. Apneustic center (lower pons): stimulates the DRC
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52
Q

Describe the location and function of central chemoreceptors

A
  • located in the medulla
  • responds to H+ concentration in the CSF
  • H+ in the CSF is a function of PaCO2 of the blood (remember, PaCO2 is the primary stimulus to breathe)
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53
Q

Describe the location and function of peripheral chemoreceptors

A
  • located in the carotid bodies: Nerves of Hering > Glossopharyngeal n. (CN IX)
  • located in the aortic arch: Vagus n. (CNX)
  • the respond to decreased O2, increased CO2, and increased H+
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54
Q

Which reflex prevents overinflation of the lungs?

A

Hering-Breuer inflation reflex

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55
Q

What is hypoxic pulmonary vasoconstriction and what triggers it to occur

A
  • HPV minimizes shunt by reducing blood flow through poorly ventilated alveoli (think atelectasis of OLV)
  • a low alveolar PO2 (not arterial PO2) is the trigger that activates HPV; the effect begins almost immediately and reaches full effect in 15 min
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56
Q

What things impair HPV?

A

Anything that inhibits HPV increases shunt (perfusion without ventilation):

  • halogenated anesthetics > 1 - 1.5 MAC
  • phosphodiesterase inhibitors
  • dobutamine
  • vasodilators

**IV anesthetics do NOT inhibit HPV

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57
Q

What does the diffusing capacity for carbon monoxide tell us?

A
  • The diffusion capacity for carbon monoxide (DLCO) is used to asses how well the lung can exchange gas
  • normal = 17 - 25 mL/CO/min/mmHg
  • using Fick’s Law of diffusion, the DLCO tells us two things about the alveolar-capillary interface:
  1. Surface area (decreased by emphysema)
  2. Thickness (increased by pulmonary fibrosis and pulmonary edema)

Therefore, DLCO is reduce by anything that reduces alveolar surface area and/or increases the thickness of the alveolar-capillary interface

58
Q

How us tobacco smoke harmful?

A

Smoking increases SNS tone, sputum production, carboxyhgb concentration, and the risk of infection

59
Q

Describe the short term benefits of smoking cessation

A

Short term cessation does NOT reduce the risk of postoperative pulmonary complications, but short term benefits include:

  • SNS simulating effects of nicotine dissapate after 20-30 minutes
  • P50 returns to near normal in 12 hours (CaO2 improves)
60
Q

Describe the intermediate effects of smoking cessation (5)

A

The return of normal pulmonary function requires at least 6 weeks and includes:

  • airway function
  • mucocilliary clearance
  • sputum production
  • pulmonary immune function

**hepatic enzyme induction subsides after 6 weeks

61
Q

Discuss the different flow-volume loops and give examples

A
  1. Normal: upside down ice cream cone
  2. Obstructive: normal inspiration with expiration obstruction (ex: COPD)
  3. Restrictive: shape is similar to normal loop, but smaller and right shifted (pulmonary fibrosis)
  4. Fixed: parallelogram (tracheal stenosis)
62
Q

What is the treatment for bronchospasm? (8)

A
  • 100% FIO2
  • deepen anesthetic
  • inhaled beta-2 agonist (albuterol)
  • inhaled anticholinergic (ipratrpium)
  • epi 1 mcg/kg/ IV
  • hydrocorisone 2-4 mg/kg IV (takes several hours to take effect)
  • aminophylline
  • helium-oxygen (Heliox) reduces airway resistance (decreased Reynold’s number)

**Montelukast is not used in the tx of acute bronchospasm

63
Q

What is alpha-1 antitrypsin deficiency? What is the definitive treatment?

A
  • alveolar elastase is a naturally occurring enzyme that breaks down pulmonary connective tissue; this enzyme is kept in check by alpha-1 antitrypsin (produced in the liver)
  • when there’s a deficiency, alveolar elastase is free to wreak havoc on pulmonary connective tissue > this ultimately leads to panlobular emphysema

**liver transplant is the definitive tx for alpha-1 antitrypsin deficiency

64
Q

Describe the goals and strategies for mechanical ventilation in the patient with COPD

A

The goal is to prevent barotrauma and reduce air trapping:

  • low Vt (6-8 mL/kg IBW)
  • increased expiratory time to minimize air trapping
  • slow inspiratory flow rate optimizes V/Q matching
  • low levels of PEEP are ok, so long as air trapping does not occur
65
Q

Define restrictive lung disease

A
  • impaired lung expansion
  • decreased lung volumes
  • normal pulmonary flow rates
66
Q

Give examples of intrinsic lung diseases (acute and chronic)

A

Intrinsic (affects lung parenchyma)

  • acute: aspiration, negative pressure pulmonary edema
  • chronic: pulmonary fibrosis, sarcoidosis
67
Q

Give examples of extrinsic lung disease

A

Extrinsic (affects areas around the lungs)

  • chest wall/mediastinum: kyphoscoliosis, flail chest, NM disorder, mediastinal mass
  • Increased intraabdominal pressure: pregnancy, obesity, ascites
68
Q

List the non-obvious S&S of aspiration pneumonitis

A
  • ascites
  • difficult airway management
  • cricoid pressure
  • impaired airway reflexes
  • head injury
  • residual NM blockade
69
Q

Describe the pharmacologic prophylaxis of aspiration pneumonitis

A
  • antacids: sodium citrate, sodium bicarbonate, magnesium trisilicate
  • H2 antagonists: ranitidine, cimetidine, famotidine
  • GI simulants: metroclopramide
  • PPI’s: omeprazole, lansoprazole, pantoprazole
  • antiemetics: droperidol, ondansetron

**Anticholinergics to reduce the risk of aspiration is not recommended

70
Q

What is Mendelson’s syndrome?

A

A chemical aspiration pneumonitis that was first described in OB patients receiving inhalation anesthesia. Risk factors include:

  • gastric pH <2.5
  • gastric volume >25 mL (0.4 mL/kg)
71
Q

Treatment of aspiration

A
  • tilt the head downward or to the side (first action)
  • upper airway suction to remove particulate matter
  • lower airway suction is useful for removing particulate matter; it doesn’t help the chemical burn from gastric acid
  • secure the airway to support oxygenation
  • PEEP to reduce shunt
  • bronchodilators to reduce wheezing
  • lidocaine to reduce the neutrophil response
  • *steroids probably don’t help
  • *abx are only indicated if the pt develops a fever or an increased WBC count > 48 hrs
72
Q

Discuss the pathophysiology and treatment of flail chest

A

Key characteristic is paradoxical movement of the chest wall at the site of fractures

Inspiration (negative intrathoracic pressure):
- normal: the chest wall moves outward & lungs expand
Flail chest: the injured ribs move inward and collapses after affected region

Expiration (positive intrathoracic pressure)

  • normal: the chest wall moves inward & lungs empty
  • flail chest: the injured ribs move outward & affected region doesn’t empty

**treatment: epidural catheter or intercostal nerve blocks (higher risk of LA toxicity)

73
Q

Define pulmonary HTN, and discuss causes and goals of anesthetic management

A

Defined as a mean PAP > 25 mmHg

  • causes: COPD, left-sided heart disease, connective tissue disorders
  • goals: optimize PVR
74
Q

Discuss things that increase PVR (8)

A
  1. Hypoxemia
  2. Hypercarbia
  3. Acidosis
  4. SNS stimulation
  5. Pain
  6. Hypothermia
  7. Increased intrathoracic pressure (PEEP, atelectasis, mechanical ventilation)
  8. Drugs (nitrous oxide, Ketamine, Desflurane)
75
Q

Discuss things that decrease PVR (5)

A
  1. Increased PaO2
  2. Hypocarbia
  3. Alkalosis
  4. Decreased intrathoracic pressure (preventing coughing/straining, normal lung volumes, spont ventilation, high frequency jet ventilation)
  5. Drugs (inhaled nitric oxide, nitroglycerin, posphodiesterase inhibitors (Sildenafil), prostaglandins (PGE1 and PGI2), CCB’s, ACE inhibitors
76
Q

Discuss the pathophys of carbon monoxide poisoning

A

CO reduces the O2 carrying capacity of blood (left shift). It binds to the O2 binding site on the hgb with an affinity of 200x that of O2. Oxidative phosphorylation is impaired and metabolic acidosis results

  • CO is measured with a co-oximeter (NOT pulse ox)
  • pts take on a cherry red appearance
  • SNS stimulation may be confused with light anesthesia or pain
  • If soda lime is dessicated, then volatile anesthetics can produce CO (Des > Iso > > > > Sevo)
77
Q

What is the treatment of CO poisoning?

A
  • 100% FIO2 until CoHgb is less than 5% for 6 hours

- hyperbaric O2 if CoHgb >25% or the pt is symptomatic

78
Q

What are the absolute indications for OLV?

A
  1. Isolation to one lung to avoid contamination
    - infection
    - massive hemorrhage
  2. Control of distribution of ventilation
    - bronchopleural fistula
    - surgical opening of major airway
    - large unilateral cyst of bulla
    - life threatening hypoxemia r/t lung dx
  3. Unilateral bronchopulmonary lavage
    - pulmonary alveolar proteinosis
79
Q

What are the relative indications for OLV?

A
  1. Surgical exposure (HIGH priority)
    - thoracic aortic aneurysm
    - pneumonectomy
    - thoracoscopy
    - upper lobectomy
    - mediastinal exposure
  2. Surgical exposure (lower priority)
    - middle and lower lobectomy
    - esophageal resection
    - thoracic spinal surgery
  3. Pulmonary edema s/p CABG
  4. Severe hypoxemia r/t lung dx
80
Q

Discuss how anesthesia in the lateral decubitus position affects the V/Q relationship

A

Nondependent lung:

  • moves from flatter region (less compliant) to an area of better compliance (slope)
  • ventilation is optimal in this lung

Dependent lung:

  • moves from the slope to the lower, flatter area of the curve (less compliant)
  • perfusion is best in this lung (effects gravity)
  • a reduction of alveolar volume contributes to atelectasis

** the nest effect is that ventilation is better in the nondependent lung and perfusion is better in the dependent lung; this creates V/Q mismatch

81
Q

What is the management of hypoxemia during OLV

A
  • 100% FIO2
  • Confirm DLT position with bronchoscope (poor position is the most common DLT complication)
  • CPAP 10 cm H2O to non-dependent lung (non-ventilated lung)
  • PEEP 5-10 cm H2O to dependent (ventilated lung)
  • Alveolar recruitment maneuver
  • Clamp pulmonary artery to the non-dependent lung
  • resume two-lung ventilation

**if hypoxemia is severe, it’s prudent to resume two lung ventilation promptly

82
Q

What is mediastinoscopy and why is it performed?

A

It is performed to obtain biopsy of paratracheal lymph nodes at the level of the carina. This helps the surgeon stage the tumor prior to lung resection

83
Q

What are the potential complications of mediastinoscopy? (7) Most common?

A
  1. Hemorrhage (most common): vascular injury
  2. Pneumothorax (second most common): pleural injury
  3. Impaired cerebral perfusion: innominate compression
    * *place an a-line on the RUE to monitor
  4. Dysrhythmias (stimulation of the carotid, aorta, or trachea)
  5. Air embolism (venous injury and air entrapment)
  6. Chylothorax: thoracic duct injury (left chest ONLY)
  7. Hoarseness and/or vocal cord paralysis: RLN or vagus injury
84
Q

Discuss the Mallampati score

A
  • class I: pillars, uvula, soft palate, hard palate
  • class II: uvula, soft palate, hard palate
  • class III: soft palate, hard palate
  • class IV: hard palate ONLY
85
Q

Describe the inter-incisor gap. What is normal?

A

The pt’s ability to open the mouth affects your ability to align the oral, pharyngeal, and laryngeal axes. A small inter-incisor gap creates a more acute angle between the oral and glottic openings, increasing the difficulty of intubation

Normal: 2-3 finger breaths or 4 cm

86
Q

What is the thyromental distance and what values suggest an increased risk of difficult intubation?

A

The TMD helps us to estimate the size of the submandibular space

With the neck extended and the mouth closed, measure the distance from the tip of the thyroid cartilage to the tip of the mentum. Laryngoscopy may be more difficult of the TMD is less than 6 cm (3 fingerbreadths) or greater than 9 cm

87
Q

What is the mandibular protrusion test and what values suggest an increased risk of difficult intubation?

A

The MPT assess the function of the temporomendibular joint. The pt is asked to sublux the jaw and the position of the lower incisors it compared to the position of the upper incisors

  • class I: pt can move LI past UI and bite the vermilion of the lip
  • class II: pt can move the LI in line with UI
  • class III: pt cannot move the LI past UR (increased risk of difficult intubation)
88
Q

What conditions impair alanto-occipital joint mobility?

A
  • degenerative joint disease
  • rheumatic arthritis
  • ankylosing spondylitis
  • trauma
  • surgical fixation
  • Klippel-Feil
  • down syndrome
89
Q

Describe the Cormack and Lehanne score

A

The Cormack and Lehanne score grading system helps us measure the vein we obtain during direct vision laryngoscopy.

90
Q

List the 5 risk factors for difficult mask ventilation

A

BONES

B - beard
O - obese (BMI > 26)
N - no teeth
E - elderly (age > 55 yrs)
S - snoring
91
Q

List 10 risk factors for difficult tracheal intubation

A
  1. Small mouth opening
  2. Palate is narrow with high arch
  3. Long upper incisors
  4. Inter-incisor distance < 3 cm
  5. Mallampati 3 or 4
  6. Mantibular protrusion test class 3
  7. Poor compliance of submandibular space
  8. TMD < 6 cm or > 9 cm
  9. Neck is thick and short
  10. Poor AO joint mobility
92
Q

List 6 risk factors for difficult subglottic device placement

A
  1. Limited mouth opening
  2. Upper airway obstruction (prevents passage of device into pharynx)
  3. Altered pharyngeal anatomy (prevents seal)
  4. Poor airway compliance (requires excessive PIP)
  5. Increased airway resistance (requires excessive PIP)
  6. Lower airway obstruction
93
Q

List 5 risk factors for difficult invasive airway placement

A
  1. Abnormal neck anatomy (tumor, hematoma, abcess, hx of radiation)
  2. Obesity (can’t ID cricothyroid membrane)
  3. Short neck (can’t ID cricothyroid memberane)
  4. Limited access to cricothyroid membraine (halo, neck flexion deformity)
  5. Laryngeal trauma
94
Q

What is angioedema?

A

Angioedema is the result of increased vascular permeability that can lead to swelling to the face, tongue and airway. Airway obstruction is an extreme concern.

95
Q

What are two common causes of angioedema? What is the treatment for each?

A

ACE inhibitors:
- tx: epinephrine, antihistamines, steroids (just like anaphylaxis)

C1 esterase deficiency (hereditary angioedema)
- tx: C1 esterase concentrate or FFP (NOT epi, antihistamines or steroids)

96
Q

What is Ludwig’s angina?

A

It is a bacterial infection characterized by a rapidly progressing cellulitis in the floor of the mouth. Inflammation and edema compress the submandibular, submaxillary, and sublingual spaces.

The most significant concern is posterior displacement of the tongue resulting in complete subglottic airway obstruction.

97
Q

What is the best way to secure the airway in the pt with Ludwig’s edema?

A

AWAKE via:

  1. Nasal intubation
  2. Tracheostomy
98
Q

Describe NPO/fast guidelines before surgery to reduce the risk of pulmonary aspiration

A
  • 2 hours = clear liquids
  • 4 hours = breast milk
  • 6 hours = nonhuman milk, infant formula, sold food
  • 8 hours = fried or fatty foods

Ingestion of clear liquids 2 hours before surgery reduces gastric volume and increases gastric pH.

99
Q

What oropharyngeal airway is the best suited for fiberoptic intubation?

A

Ovassapian or Williams

**Williams is used for blind orotracheal intubation also

100
Q

What is the best time to use an Eschmann introducer?

A

When a grade 3 view is obtained during laryngoscopy (grade 2 is the next best time). The likelihood of successful intubation is unacceptably low when a grade 4 view is obtained.

101
Q

When is a nasopharyngeal airway contraindicated?

A

Cribiform plate injury (risk of brain injury)

  • LeFort II or III fracture
  • basilar skull fracture
  • CSF rhinorrhea
  • raccoon eyes
  • periorbital edema

Also:

  • coagulopathy
  • previous transsphenoidal hypophysectomy
  • pprevious Caldwell-Luc procedure
  • nasal fracture

**caution during pregnancy d/t risk of epistaxis

102
Q

Contrast the maximum recommended cuff pressure for an endotracheal tube vs. LMA

A

ETT: < 25 cm H2O
LMA: < 60 cm H2O

103
Q

Compare and contrast the maximum recommended PIP for an LMA-Unique vs LMA-Proseal vs LMA-Supreme

A

LMA-Unique: < 20 CM H2O

LMA-Proseal: < 30 cm H2O

LMA-Supreme: < 30 cm H2O

104
Q

Discuss LMA sizes regarding weight and how much air to add to the cuff

A 
#1 (<5 kg): 4 mL
#1.5 (5-10 kg): 7 mL
#2 (10-20 kg): 10 mL
#2.5 (20-30 kg): 14 mL
#3 (30-50 Kg): 20 mL
#4 (50-70 kg): 30 mL
#5 (70-100 kg): 40 mL

**#3 & 4 fit a 6.0 ETT and #5 fits a 7.0 ETT

105
Q

List 5 indications for the Bullard laryngoscope

A

Indications:

  1. Small mouth opening (minimum 7 mm)
  2. Impaired cervical spine mobility
  3. Short, thick neck
  4. Treacher Collins syndrome
  5. Pierre-Robin syndrome
106
Q

Describe the proper placement of the lighted stylet

A

When the pt is supine, the trachea is anterior to the esophagus. Therefore, we can look at the quality of the light shinning through the neck to determine if the tip of the device is located in the trachea or esophagus.

  • When the lighted stylet is in the trachea, the light has to travel through less tissue so you’ll observe a well-defined circumscribed glow below the thyroid prominence
107
Q

List 5 indicators for the use of a bronchial blocker

A
  1. Children <8 years of age (smallest DLT = 26 Fr for 8-10 year)
  2. Require nasotracheal intubation
  3. Have a tracheostomy
  4. Have a single lumen ETT in place
  5. Require intubation after surgery and you want to avoid changing the DLT to a single-lumen ETT @ the end of the case
108
Q

How can the lumen of the bronchial blocker be used during OLV?

A

It can be used:

  • insufflate into the non-ventilated lung
  • suction air from the non-ventilated lung (improves surgical exposure)

It CANNOT be used to:

  • ventilate
  • suction blood, pus or secretions form the non-ventilated lung
109
Q

List 2 indications for retrograde intubation

A
  1. Unstable cervical spine (most common reason)
  2. Upper airway bleeding (can’t visualize glottis)

**since RSI requires time (~5-7 min), retrograde intubation has failed but ventilation is still possible

110
Q

Compare and contrast the benefits of awake vs deep extubation

A

Awake:

  • pros: airway reflexes intact, ability to maintain airway patency, decreased risk of aspiration
  • cons: increased CV and SNS stimulation, increased coughing, increased intracranial pressure, increased intraocular pressure, increased intraabdominal pressure

Deep:

  • pros: decreased CV and SNS stimulation, decreased coughing
  • cons: airway reflexes are ineffective, increased risk of airway obstruction, increased risk of aspiration
111
Q

When is the best time to use an airway exchange catheter, and what can you do with it?

A

The airway exchange catheter is a long, thin, flexible, hollow tube that maintains direct access to the airway following tracheal extubation. It is the most common device used to manage extubation of the difficult airway.

What else can you do with a AEC?

  • EtCO2 measurement
  • jet ventilation (via Luer-lock adapter)
  • oxygen insufflation (via 15 mm adapter)
112
Q

Match the nerve to the structure it innervates

A
  1. Trigeminal = anterior tongue
  2. Glossopharyngeal = vallecula
  3. Recurrent laryngeal = trachea
  4. Superior Laryngeal = posterior epiglottis
113
Q

Which situation would be likely to injury the left RLN, but spare the right RLN?

A

Mitral stenosis
- the right RLN loops under the right subclavian artery, while the left loops under the aorta; this makes the left RLN more susceptible to injury

  • the left atrium enlarges d/t mitral stenosis which compresses the subclavian artery
114
Q

What are causes of left RLN (only) injury? (4)

A
  1. Mitral stenosis: left atrial enlargement compresses the nerve and may present as hoarsness
  2. PDA ligation
  3. Aortic arch aneurysm
  4. Thoracic tumor
115
Q

What are causes of right and left RLN injury? (4)

A
  1. Parathyroid or thyroid surgery
  2. External pressure from LMA or ETT
  3. Neck tumor
  4. Neck extension
116
Q

Order the cartilages from superior to inferior (4)

A
  1. Epiglottis
  2. Corniculate
  3. Arytenoid
  4. Cricoid
117
Q

Which cervical level is the larynx located?

A

C3-C6

118
Q

What are the three landmarks for Larson’s maneuver?

A
  1. Superior: Skull base
  2. Anterior: Ramus of mandible
  3. Posterior: Mastoid process
119
Q

What are the function of the three types of pneumocytes? Which one produces surfactant?

A
  1. Type I: cells where gas exchange occurs ~ 80% of alveolar surface
  2. Type II: produce surfactant
  3. Type III: macrophages that fight lung infection
120
Q

What is the most common etiology of hypoxemia in the PACU? What is the treatment?

A
  • ventilation/perfusion mismatch
  • V/Q mismatch (specifically atelectasis) is the most common cause of hypoxemia post-op
  • tx: humidified O2, mobility, pulmonary toileting (coughing, deep breathing, incentive spirometry)
121
Q

When does intrapleural pressure become positive?

A
  • forced exhalation
122
Q

Compared to spontaneous ventilation, what happens to Vd/Vt ration when a pt is placed on a vent?

A
  • it increases d/t increased dead space
123
Q

What are three reasons a pt’s PaCO2 has increased, but their EtCO2 has decreased?

A
  1. Hypotension: a reduction in CO is the MOST common reason
  2. COPD
  3. AFE

**increasing the tubing length of the circle system will NOT cause this

124
Q

What is the consequence of PaCO2 and PaO2 when adding a HME in between the ETT and the y-piece?

A

PaCO2 increases, and PaO2 decreases because the HME increases apparatus dead space

125
Q

What three venous systems contribute to anatomic shunt?

A
  1. Thebasian veins (drain left heart)
  2. Bronchiolar veins (drains bronchial circulation)
  3. Pleural veins (drains bronchial circulation)
126
Q

When does venous admixture increase?

A
  • when expiratory volume decreases
  • when you see shunt or venous admixture, think FRC; a reduction in ERV leads to a reduction in FRC
  • a smaller FRC decreases the amount of pulmonary blood that comes into contact with oxygenated alveoli per unit time
127
Q

EMLA cream does what to P50 and the oxyhgb dissociation curve?

A
  1. Decreases P50

2. Shifts oxyhgb dissociation curve to the left

128
Q

What is the Hamburger Effect?

A

The hamburger effect describes how Cl- is exchanged for HCO3- to maintain electroneutrality when the erythrocyte acts as a buffer

129
Q

Which phenomenon is responsible for tachypnea that accompanies PE?

A

J receptor stimulation

  • these receptors are activated by a PE or during pulmonary vascular congestion, such as CHF
130
Q

Anesthesia-induced atelectasis is BEST reversed by what?

A

Increasing peak airway pressures to 40 cm H2O for 8 seconds

- AKA recruitement maneuver

131
Q

What is the difference between emphysema and chronic bronchitis?

A
  • chronic bronchitis is caused by inflammation and mucus production that reduce airway diameter
  • emphysema is caused by a reduction in the surface area of the alveolarcapillary interface and loss of elastic recoil
132
Q

What are the S&S of cor pulmonale?

A
  • cor pulmonale is R sided heart failure that results from pumonary HTN. S&S:
    1. JVD
    2. Hepatomegaly
    3. Lower extremity edema

**an increased PAOP is consistent with LV (NOT RV) failure

133
Q

What tx is indicated immediately after nonparticulate aspiration?

A

Positive end-expiratory pressure

134
Q

List two causes of an increased A-a gradient

A
  1. Pneumonia

2. PE

135
Q

Match inhaled drugs with their MOA

A
  1. Montelukast = leukotriene antagonist
  2. Theophylline = phosphodiesterase inhibitor
  3. Cromolyn = mast cell stabilizer
  4. Ipratropium = anticholinergic
136
Q

A pt is scheduled for a left pneumonectomy. Crystalloid administration should be less than what?

A

3 liters in 24 hours

  • excessive crystalloid administration increases hydrostatic pressure, which increases interstitial lung water and impairs gas exchange
137
Q

What is the #1 and #2 reliable signs of endotracheal intubation?

A 
#1. EtCO2
#2. Endotracheal tube visualized between the vocal cords
138
Q

Which nerve innervates the valleula?

A

Glossopharyngeal nerve

139
Q

Compared to using the Trachlight in the adult population, in children

A
  1. There is a higher incidence of false positive results
  2. The bend should be closer to the tip
  3. Transillumination will occur sooner

**in kids, the tip should be bent at a MORE acute angle (60-80 degrees) to better accommodate a more cephalad glottic opening

140
Q

What is the ONLY absolute contraindication to a cricothyroidotomy?

A

Age less than 6 yrs

141
Q

Steps of the treatment of an airway fire

A
  1. Remove the ETT
  2. Stop flow of all airway gases
  3. Pour saline into the airway
  4. Re-establish ventilation

BOARD REVIEW (3 decks)

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