Anesthesia Flashcards

1
Q

What drugs should be avoided in severe respiratory patients?

A

Alpha-2 -> Respiratory depression
Beta blockers -> don’t use with pneumothorax patients
Avoid high spinal epidurals

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2
Q

In a patient on a ventilator with pleuritis, what pressures should you not exceed?

A

Pressure should be less than or equal to 10cm H20

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3
Q

What are concerns of reintroducing negative pleural pressure too quickly with a patient that has chronic atelectasis?

A

Re-expansion pulmonary edema

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4
Q

What patients should be on a non-rebreathing system?

A

Tobias says <5kg; Lumb/Jones says <10kg (ideally 3-7kg)

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5
Q

What general steps occur when the CO2 absorbs in the rebreathing system?

A

Absorbent contains various concentrations of Ca(OH)2 and CO2 + hydroxides -> carbonic acid -> H2O + CaCO2

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6
Q

What is the flow rate formula for a rebreathing system?

A

10x BW (kg) ^0.75 = 3-6 mL/kg/min

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7
Q

What is the recommended flow rate for a non-rebreathing system?

A

3x patient’s minute volume (MV = RR x TV)
~200-300 mL/kg needed to prevent rebreathing

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8
Q

What are the phases of the waveform on end-tidal CO2 monitors?

A

0: fresh gas passes sensor
1: CO2 from lungs passes sensor, elevating waveform
2: Plateau once mixing of dead space gas
3: Waveform peaks during end of expiration
4: Inspiration draws fresh gas over sensor, waveform drops to baseline

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9
Q

Draw how an end tidal CO2 waveform would change in the following situations:
1. Hypoventilation
2. Hyperventilation
3. Rebreathing CO2
4. Leak in circuit

A
  1. Increase in height of plateau
  2. Decrease in height of plateau
  3. The waveform does not return to zero/baseline at inspiration
  4. “Sail” shaped end to waveform vs nice plateaus with sharp drop at inspiration
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10
Q

What nerve blocks are available for dental procedures?

A

Mental
Inferior alveolar
Infraorbital
Maxillary

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11
Q

What dose of bupivicaine do you use in dogs vs cats?

A

2.5mg/kg dog

1mg/kg cats

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12
Q

What induction agents can increase intraocular pressures?

A

Ketamine and propofol

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13
Q

What are the heat exchange mechanisms in anesthetized patients?

A

Evaporation= lungs/feet
Conductive = cold surfaces, water washing
Radiation = loss of infrared energy

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14
Q

What is the most effective method of warming anesthetized patients?

A

Forced warm air

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15
Q

Normal CVP with monometer?

With transducer?

A

0-8cm H2O

0-5mmHg

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16
Q

What are four methods of nonivasive cardiac output monitoring and describe how performed?

A
  1. Thermodilution (themometer tipped pulmonary catheter / inject saline at known temp -> AOC of temp change is CO)
  2. Lithium dilution (inject Li venous, aspirate from arterial)
  3. Pulse contour analysis (arterial BP waveform after calibration via Lithioum or thermo)
  4. Noninvasive CO (uses CO2 to estimate O2 consumption via Fick principle).
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17
Q

How does the pulseOx calculate SpO2?

What HCT level will cause changes in SpO2 on pulseOx?

What are common causes of inaccurate SpO2 readings?

A

Calculates by Hb absorbtion within the arterial pulsatile component of the path the light travels.

HCT <10%

Vasoconstriction/lowCO, hypothermia, pain, alpha-2 agonists

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18
Q

How does uremia make catheters problematic?

What drugs should be used with caution as pre-med/induction in renal dz patients?

What local block should be avoided?

What can be given to dogs with poor urine output to improve urine flow?

A

Uremia impairs platelet function.

  • Alpha-2s increase urine output so don’t use in obstructions.
  • ketamine is excreted unchanged in cat urine

Avoid epidurals because of the possibility of platelet dysfunction/hemorrhage

Mannitol, furosemide, dopamine to increase flow

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19
Q

When heart failure occurs, what 2 neurohormonal changes occur that affect anesthesia?

A

Body activates the RAAS -> fluid retention and hypervolemia; also upregulates the sympathetic NS

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20
Q

What are anesthetic monitoring changes seen with air embolus?

A

Sudden decrease in ETCO2, drop in BP and pulseOx, +/- audible “washing machine” murmur

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21
Q

What induction drug should be avoided in thyroid patients, especially hyperthyroid?

A

Ketamine because may have concurrent heart disease and because it can induce a thyroid storm

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22
Q

What 3 drugs can be given to patients with insulinomas while under anesthesia?

A

-Glucocorticoids (promote insulin resistance and gluconeogenesis)
-Glucagon to normalize BG 5-13mg/kg/min
- alpha-2s increase insulin resistance

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23
Q

What drugs should be available for emergency surgeries on the biliary tree?

Which opioids are best for premed of liver patients? Why?

Which induction agent is best for liver?

A

Anticholinergics because can have increased vagal tone

Morphine, hydromorphone, oxymorphone -> don’t need P450 for clearance and don’t accumulate in tissues

Propofol has extrahepatic sites for metabolism +/- ket/midaz

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24
Q

What is absorbtion atelectasis?

A

Alveolar collapse when O2 replaces N volume then is rapidly absorbed -> no more volume to hold open

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25
Q

What causes malignant hyperthermia?

What do you treat with?

A

Defect in ryanodine receptor (Ca++ release)

Dantrolene to decrease Ca release

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26
Q

What HCT level will cause changes on SpO2 on pulse oximeter?

A

<10% HCT

27
Q

Put in order fastest to slowest change in body temperature over time:

  • 3 blankets
  • 1 blanket
    airway heat/humidification
    -circulating water blanket
  • forced air
A

Fast:

Forced air
3 blankets
circulating water mattress
one blanket
airway heat/humidity

Slow

28
Q

Which gas does charcoal not scavenge?

A

N2O

29
Q

With V/Q mismatch, do you see hypercapnia?

A

Not usually because CO2 has a high diffusion capacity

30
Q

What is the difference between a Miller and a MacIntosh laryngoscope?

A
31
Q

What drugs are helpful for anesthesia in a dog with DCM?

What drug may increase potential for arrhythmias under anesthesia?

Generally, for anetshesia in heart dz, what premeds should you pick?

Best induction agent?

One to avoid?

A

dobutamine (inotropic)

digoxin may increase arrhythmias

premeds:
- opioid + tranquilizer (neuroleptanalgesia) avoid ace if hypotensive, avoid alpha-2, avoid ketamine

Induction - etomidate best, propofol/alfax caution, ketamine contraindicated

32
Q

How does warm weather affect vaporizer output?

What are the 2 ways of vaporizer output?

What are the three methods of vaporization?

Why does desflurane need a specific vaporizer?

A

increases output

bypass (measured flow / 2 separate flows) or flow-over/bubble through/direct injection

desflurane has a specific boiling point that it needs to be heated to in order to become gas

33
Q

How much (in mmHg) does the doppler often underestimate in cats?

How does oscillometric BP work? What does it underestimate?

A

less than or equal to 25mmHg

returning bloodflow causes turbulence sensed as a pressure oscillation
- greatest oscillation = MAP
-abscence of oscillations = DAP
it underestimates SAP,DAP,MAP in dogs and SAP in cats

34
Q

What are parameter changes with malignant hyperthermia?

Why is there muscle rigidity?

How do you treat malignant hyperthermia?

A

hypercarbia, hyperthermia, muscle rigidity, arrhythmias, death

Ryanodine receptor defect -> Ca release

Treat by d/c inhalants, IV dantrolene, convert to TIVA if need to stay under

35
Q

What premed to avoid with adrenal disease?

Which induction to avoid?

A

acepromazine -> can cause alpha antagonism and complicate sympathetic tone management

alpha2 effects in pheos are unpredictable

etomidate - avoid in Addisons because supresses steroids

36
Q

Which induction to avoid in septic patients?

Premeds to avoid with sepsis?

Which gas can be used with maintenance and fentanyl in sepsis?

A

Etomidate - these dogs often have corticosteroid deficiency from sepsis

alpha2 and acepromazine

N2O

37
Q

List and describe the 5 ASA statuses

A

1= no systemic illness healthy
2= mild compensated systemic illness
3= mod->severe compensated illness
4= patient has disease that is constant threat to life
5= moribund patient not expected to survive 24hr with or without treatment

38
Q

What is an SGAD?
Other name?

Benefits?

A

Supraglottic airway device (aka laryngeal masks)

good for rabbits, maybe you need less anesthetic

39
Q

Where do you place the (+) and (-) electrodes on the peripheral nerve stimuator?

What is train of four analysis?

What must you not give until all four twitches return?

A

negative closer to body, positive distal to induce twitch

4 stimuli over 2 sec. Increased receptor blockage causes fade of the strength of contraction with decreased amplitude of twitch -> eventually no twitch

Do not give pharmacological reversal agent. Gotta wait for there to be a low enough level of NM blocker at junctions for this to be overcome by the increased acetylcholine

40
Q

Which heart conditions should NOT be treated with lidocaine?

A

Those with third degree av block and those with ventricular escape rhythms

41
Q

List examples of regional blocks

A

RUMM
Femoral/sciatic (or saphenous)
epidural
brachial plexus
paravertebral
Esmarsch (Bier block)

42
Q

What are 5 causes of hypoxemia?

Which is most common?

A

Hypoventilation, R->L shunt, decreased inspired O2, diffusion impairment, V/Q mismatch

V/Q mismatch

43
Q

What determines an ascending or descending ventilator bellows?

A

Ascending “stands” during expiration

Descending “hangs” during expiration

44
Q

What is the contraindication for giving anticholinergics (atropine/glyco) to treat bradycardia caused by dexmed or other alpha2s?

A

Will result in increased cardiac work and severe hypertension

45
Q

What drugs are recommended to have nearby for all neonatal anesthesia?

Which is the most important heart parameter to maintain in neonates?

A

Anticholinergics

HR - neonates have trouble increasing stroke volume

46
Q

What volume do you use for a lumbosacral epidural?
For a thoracic + abdomen coverage?

If local epidural spreads to ganglia of sympathetic chain -> vasodilation -> how do you treat?

A

0.2mL/kg
0.3mL/kg for thoracic/abdomen

IV bolus phenylephrine or dopamine

47
Q

What are some anesthetic machine/factors causing hypercapnia?

A

Expired/exhausted soda lime
Expiratory valve damaged
Fresh gas flow not high enough in a non-rebreathing circuit

48
Q

Heart patients with stenotic lesions may benefit from what drugs?

A

anticholinergics

49
Q

What is the Branham reflex?

A

reflexive drop in HR after ligation of a PDA due to abrupt increase in afterload / increased systolic BP

50
Q

What are criteria for treating VPCs?

A

Vtach (>150), multiform, syncopal event/hypotension, R on T phenom, runs of VPC

51
Q

What anesthetic drugs will impair the hypoxic pulmonary vasoconstriction compensatory mechanism?

A

Inhalant anesthetics

52
Q

Why would ketamine be helpful in animals with allergic airway disease?

A

ketamine causes bronchodilation

53
Q

What drug class should be added to premed for brachycephalics and why?

A

anticholinergics because brachys have increased vagal tone

54
Q

What situation/patient dz would lead you to pick pressure-cycled ventilator over volume?

A

Pressure cycled is better for dogs with changing pulmonary compliance (severe airway disease) because a volume cycled would make pressures too high

55
Q

What diastolic arterial pressure indicates poor coronary artery perfusion?

A

<40mmHg

56
Q

What can be added to O2 to protect against fires from laser use?

A

Helium 70:30 with O2

57
Q

What are the colors for the gas tanks?
O2
NO2
He
CO2
N
Room air?

A

O2 - green/white
NO2 - Blue
He - Brown
CO2 - Gray
N - Black
Room air - Yellow

58
Q

What are the main anesthetic concerns with adrenal dz patients (cushings, addisons, pheo)?

A

Cushings = infection risk, hypovolemia (from polyuria), hypercoagulable/PTE

Addison’s -> hypovolemia/GI shock (avoid etomidate)

Pheo = tachycardia or bradycardia, arrhythmias, hypertension (alpha-blockers, +/- nitroprusside)

59
Q

What analgesics should be used with caution in hyperthyroid patients?

A

avoid NSAIDs because these patients are at risk for renal dz

60
Q

With diabetic patients, when do you give dextrose boluses?

Should patients be given their morning insulin?

A

When BG is <70, and then start 2.5% dextrose in fluids after bolus

no morning meal-> give 1/2 normal insulin dose

61
Q

With laparoscopy, decreased renal blood flow is seen at ____cmH2O?

A

> 14cmH2O

62
Q

Which drug is the one shown to adversley affect neonatal survival?

A

Xylazine

63
Q

With anesthesia on cats with HCM, what are some physiology factors that affect protocol choices?

A

-poor preload so use Beta blockers/calcuim blockers to increase diastolic fill time
- systolic anterior motion of the anterior mitral valve leaflet compromises CO -> consider IVF
- caution with dobutamine as it increases the myocardial O2 demand via tachycardia and also decreases the diastolic fill time