Everything Flashcards

1
Q

What is the mechanism for toxic sideffects of Nitrous Oxide?

A

Blocks Vitamin B12 dependent enzymes, such as thymidylate synthase (DNA synthesis) and methionine synthase (myelin formation).

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2
Q

What are the side effects of nitrous oxide?

A

Bone marrow suppression, peripheral neuropathies.

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3
Q

What type of patients should you not give nitrous oxide to?

A

Pregnant patients (possible teratogenic).

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4
Q

What conditions are hazardous to use nitrous oxide in?

A

Venous or arterial air embolism, pneumothorax, acute intestinal obstruction, intracranial air, pulmonary air cysts, intraocular air bubbles, and tympanic membrane grafting.

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5
Q

What effect does Isoflurane have on coronary arteries? Why could this be a problem?

A

It dilates coronary arteries, potentially creating a steal situation, where blood is diverted away from fixed stenotic lesions.

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6
Q

What effect does isoflurane have on the bronchi?

A

It is bronchodilatory.

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7
Q

How much faster is desflurane than isoflurane?

A

About 50% faster wake up time.

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8
Q

What is the blood gas partition coefficient of nitrous?

A

0.47

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9
Q

What is the blood gas partition coefficient of desflurane?

A

0.42

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10
Q

What can rapid increases in desflurane concentration lead to?

A

Elevated HR, BP, and catecholamine levels.

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11
Q

What can Desflurane, more than other volatiles, be degraded by dessicated CO2 absorbent into?

A

Carbon monoxide.

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12
Q

What are contraindications for volatile anesthetics?

A

Severe hypovolemia, malignant hyperthermia, and intracranial hypertension.

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13
Q

What is the solubility coefficient of sevoflurane?

A

0.65

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14
Q

Why is cardiac output not maintained as well with sevoflurane, as it might be with isoflurane or desflurane?

A

Because sevoflurane does not increase heart rate, so CO is not maintained.

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15
Q

What cardiac side-effect can sevoflurane have?

A

QT prolongation.

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16
Q

What increases the amount of Compound A produced by sevoflurane administration?

A

Increased temperature of gas, low flow anesthesia, high sevoflurane concentration, and anesthetics of long duration.

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17
Q

What enzyme metabolizes sevoflurane, and what multiplier is sevoflurane metabolized compared to isoflurane?

A

CPY-2E1, 10-25X more metabolized than isoflurane.

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18
Q

What is the possible complication of sevoflurane metabolism?

A

Possible rise in inorganic fluoride, which can cause renal injury.

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19
Q

What three factors affect inhaled anesthetic uptake?

A

Solubility, alveolar blood flow, and the difference between alveolar gas and venous blood gas partial pressure.

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20
Q

What factors affect speed of recovery and induction?

A

Elimination of rebreathing, high fresh gas flow, low anesthetic-circuit volume, low absorption by the anesthetic circuit, decreased solubility, high cerebral blood flow, and increased ventilation.

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21
Q

What are risk factors for halothane toxicity?

A

Multiple halothane anesthetics, middle aged obese women, persons with familial predisposition.

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22
Q

What effect does repetitive administration of barbituates have?

A

Saturates peripheral compartments, minimizing redistribution and making half-life dependent on elimination only.

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23
Q

What is the mechanism of action of barbituates?

A

Binding the GABAa receptor, increasing the duration of openings of a chloride-specific ion channel.

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24
Q

What determines the duration of effect of “sleep” doses of barbiturates?

A

Time to redistribution, for example, Thiopental will redistribute within 20 minutes.

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25
Q

What patient factors might barbiturates be a bad idea in?

A

Hypovolemia, B-blockade, and CHF, because you can get an uncompensated peripheral pooling of blood and direct myocardial depression, causing severe hypotension.

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26
Q

What effect do barbiturates have on the brain?

A

They constrict cerebral vasculature, causing a decrease in cerebral blood flow, cerebral blood volume, and decrease intracranial pressure.

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27
Q

What effect do barbiturates have on CPP?

A

Intracranial pressure decreases to a greater degree than arterial BP usually, so CPP increases.

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28
Q

What side-effect can barbiturates have on the liver?

A

They can promote aminolevulinic acid synthetase, which stimulates formation of porphyrin (heme intermediary). This can precipitate acute intermittent porphyria.

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29
Q

What is the mechanism of benzodiazepenes?

A

Benzos bind to GABAa and increase the frequency of chloride ion opening.

30
Q

What is the treatment for benzodiazepene overdose?

A

Flumazenil

31
Q

What is the mechanism of Flumazenil?

A

Benzodiazepene receptor antagonist.

32
Q

Why do most benzodiazepenes have long half-lives? Why is midazolam different?

A

Long half-lives because of large volume of distribution. Midazolam has an increased hepatic extraction ratio, however, so it is shorter.

33
Q

How are benzodiazepenes excreted?

A

Urine.

34
Q

Can small doses of benzodiazepenes cause respiratory arrest?

A

Yes, although apnea is relatively uncommon, even small doses can cause respiratory arrest.

35
Q

What synergistic side-effect can you see with benzodiazepenes and opioids in induction?

A

Marked reduction in arterial BP and PVR.

36
Q

What effect does Ketamine have on SBP, HR, and ICP?

A

Increases all of them.

37
Q

What effect does Ketamine have on the bronchi?

A

It is a potent bronchodilator.

38
Q

What side effect happens with Etomidate?

A

Inhibition of enzymes involved in cortisol and aldosterone synthesis.

39
Q

What is special about the clearance of Propofol?

A

It exceeds hepatic blood flow, implying the existence of extrahepatic metabolism.

40
Q

What is propofol infusion syndrome?

A

Happens in children that are critically ill or young adult neurosurgical patients getting Propofol infusions, causing lipemia, metabolic acidosis, and death.

41
Q

What unique sideffects are beneficial in Propofol use?

A

Anti-pruritic and anti-emesis effects.

42
Q

What side-effects of Pancuronium should be considered?

A

Hypertension and tachycardia, caused by a combined vagal blockade and sympathetic stimulation.

43
Q

How is Cisatricurium degraded?

A

Hoffman elimination.

44
Q

What is the primary excretion of Vecuronium / Rocuronium?

A

Biliary

45
Q

What type of non-depolarizing muscle relaxants are Atra/Cisatracurium?

A

Benzylisoquinolones.

46
Q

What effect does long term administration of Vecuronium have, and why?

A

Extremely long neuromuscular blockade, likely from accumulation of active 3-hydroxy metabolite.

47
Q

What non-depolarizing muscle relaxant has an onset as fast as Succinylcholine? At what cost?

A

Rocuronium (0.9 mg/kg), lasts much longer.

48
Q

What non-depolarizing muscle relaxants are partially excreted by the kidneys, and thus last longer in renal failure patients?

A

Vecuronium, pancuronium, doxacurium, and pipecuronium.

49
Q

Why is succinylcholine relatively contraindicated in routine child management?

A

Risk of hyperkalemia, rhabdomyolysis, and cardiac arrest in children with unknown myopathies.

50
Q

What can happen with excessive doses of acetylcholinesterase inhibitors?

A

Paradoxical potentiation of NDMB.

51
Q

If you have a prolonged action of a NDMB from hepatic or renal insufficiency, what will likely happen to the duration of your acetylcholinesterase inhibitor?

A

Also increase, so everything will be ok.

52
Q

What is the suggested endpoint for NDMB reversal?

A

Sustained tetany for 5s in response to 100hz stimulus.

53
Q

How does Sugammadex work?

A

Bonding with steroidal NDMBs.

54
Q

CPY2D6 metabolizes which drugs?

A

Codeine, B-blockers, diltiazem, tramadol.

55
Q

CYP2C9 metabolizes which drugs?

A

Warfarin, phenytoin, ibuprofen

56
Q

CYP3A4 metabolizes which drugs?

A

Most anesthetics (incl. fentanyl), local anesthesia, and dexamethasone.

57
Q

What enzyme does Midazolam inhibit?

A

CYP3A4, which can prolong the effect of fentanyl.

58
Q

CYP3C19 metabolizes which drugs?

A

Antidepressants and PPIs

59
Q

MC1R metabolizes which drug?

A

Morphine

60
Q

Damage to the anterior hypothalamus can cause what problem?

A

Thermal dysreguation (temperature problems)

61
Q

Damage to the medial hypothalamus/posterior pituitary can cause which problems?

A

Hypotension and polyuria (cannot make vasopressin)

62
Q

What is the formula for mL of anesthetic in a bypass chamber?

A

(Vapor pressure of Gas x mL of Flow)/(Atm pressure - Gas vapor pressure)

63
Q

What is the formula for chest wall compliance?

A

1/Ccw = 1/Crs - 1/Clung

64
Q

What effect does spinal anesthesia have on the GI system?

A

Increased secretions, nausea, vomiting, etc from unopposed parasympathetic activity (spinal = sympathectomy)

65
Q

Mnemonic for rebreathing in mapleson circuit during spontaneous circulation?

A

A > D> C > B (All dogs can breathe)

66
Q

Mnemnic for rebreathing in mapleson circuit during controlled ventilation?

A

D > B > C > A (dead babies can’t assist)

67
Q

How is Nicardipene metabolized?

A

Via the liver.

68
Q

What is the side effect of Amiloride?

A

Can cause hyperkalemia (it is a potassium sparing diuretic)

69
Q

What are the four potassium sparing diuretics?

A

Amiloride, Spironolactone, Triamterene, Eplneronone

70
Q

What can HCTZ increase in the serum?

A

Hypercalcemia, hyperuricemia, hyperglycemia

71
Q

Acoustic impedence is the product of which two characteristics?

A

Density and propogation of the speed of sound.

72
Q

Plasma volume is what % of extracellular volume?

A

25%