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Anesthetic Physiology And Principles Flashcards

1
Q

What is the cause of rapid reduction in core temperature during the first hour of general anesthesia?

A

Redistribution of heat from the core to the periphery

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2
Q

What are the 2 mechanisms of undesired heat loss in the OR?

A
  1. Impaired thermoregulation secondary to anesthesia

2. Low ambient temperature of the operating theater

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3
Q

What are the 2 main “physic” ways that heat is lost in the OR.

A
  1. Radiative (67%)
  2. Evaporative (17%)
  3. Conductive and convective (16%)
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4
Q

How can you prevent heat loss from a patient?

A

By pre-warming them

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5
Q

How much does general anesthesia decrease FRC?

A

10%

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6
Q

How much is FRC reduced by lying flat?

A

10-15%

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7
Q

What happens when people go to higher altitude?

A

Increased respiratory rate to compensate for the decrease in oxygen
Increased cardiac output (returns to normal later)
Increase in Hgb over time (by decrease in plasma concentration, increase in erythropoeitin)
Rightward shift in oxygen dissociation curve ( due to hypoxia, increased 2,3-DPG
Increased hypoxic pulmonary vasoconstriction

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8
Q

What happens to the physiology of the respiratory system when a patient is main stemmed?

A

Shunting occurs

There is no increase in dead space

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9
Q

What are the 6 factors that influence the level of spinal anesthesia?

A
  1. Dose/concentration
  2. Site of injection
  3. Baricity of local anesthetic
  4. Posture of patient
  5. Volume of CSF
  6. Density of CSF
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10
Q

In what conditions is the volume of CSF reduced?

A 
Anything that increases intra abdominal pressure:
Ascites
Obesity
Pregnancy
Tumor
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11
Q

What is the best clinical sign of reversal?

A

Sustained head lift

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12
Q

What is the least greatest sign of reversal?

A

Tidal volume

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13
Q

What are the recommended points of recovery?

A

Sustained tetany for 5 seconds to a 100 Hz stimulus

Sustained head or leg lift in awake patients

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14
Q

What anesthetic technique has not been associated with exacerbation of symptoms or side effects in MS?

A

Epidural anesthesia

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15
Q

What are the effects of citrate intoxication?

A 
Hypocalcemia
Myocardial depression 
Hypotension 
Hypomagnesemia (chelated along with calcium)
Coagulopathy
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16
Q

What blood product carries the most citrate.,

A

FFP and platelets

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17
Q

In what conditions is citrate toxicity more likely?

A

Hypothermia
Liver disease
Hyperventilating
Pediatrics

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18
Q

What are the signs of citrate toxicity?

A

Hypotension
Narrow pulse pressure
Increased EDP
Increased CVP

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19
Q

How is citrate metabolized?

A

Rapidly by the liver

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20
Q

When do ionized calcium levels begin to decrease when transfusing blood?

A

When blood is given at 6 units/hr

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21
Q

What is the treatment of citrate toxicity?

A

Calcium

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22
Q

What are the effects of citrate intoxication?

A 
Hypocalcemia
Myocardial depression 
Hypotension 
Hypomagnesemia (chelated along with calcium)
Coagulopathy
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23
Q

What blood product carries the most citrate.,

A

FFP and platelets

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24
Q

In what conditions is citrate toxicity more likely?

A

Hypothermia
Liver disease
Hyperventilating
Pediatrics

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25
Q

What are the signs of citrate toxicity?

A

Hypotension
Narrow pulse pressure
Increased EDP
Increased CVP

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26
Q

How is citrate metabolized?

A

Rapidly by the liver

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27
Q

When do ionized calcium levels begin to decrease when transfusing blood?

A

When blood is given at 6 units/hr

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28
Q

What is the treatment of citrate toxicity?

A

Calcium

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29
Q

What changes would you see with a venous air embolism?

A

Decreased pulmonary perfusion so decreased ETCO2 with increased PaCO2 due to more dead space

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30
Q

What is the best way to increase FRC in a patient in steel trendelenburg?

A

Increase PEEP because it increases the volume of air in the lungs

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31
Q

What is citrate used for in blood?

A

Anti coagulation by binding calcium which prevents calcium from binding to factor IV which prevents coagulation

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32
Q

How long does it take the kidneys to eliminate the bicarbonate from citrate?

A

3-4 days

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33
Q

Why do infants have a faster rate of induction compared with adults?

A

Because they have a higher minute ventilation to FRC ratio

Their FRC is lower

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34
Q

At what age does MAC requirement reach a peak

A

6 months

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35
Q

What does glucagon do to the heart?

A

Increases contractility by increases camp which increases intracellular calcium so increases inotropy and chronograph

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36
Q

What drug should you avoid using in someone receiving bleomycin?

A

Lidocaine because it can enhance its cytotoxicity

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37
Q

What should be limited in patients receiving bleomycin?

A

FiO2 because it can aggravate the pneumonitis

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38
Q

What chemotherapy drugs are not good for doing regional anesthesia?

A

Vincristine and vinblastine because they cause peripheral neuropathy

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39
Q

How does mannitol work?

A

Osmotic Diuresis by being freely filtered by the glomerulus but poorly up taken by the vasculature so it sets up a hypertonic gradient drawing fluid into the tubule

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40
Q

How is mannitol renal protective?

A

Maintains patency of flow and flushes debris from the tubule

Also transiently sets up osmotic gradient in the vasculature so increasing circulating plasma volume

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41
Q

What are the carotid body chemoreceptors primarily responsive to?

A

Arterial partial pressure of oxygen

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42
Q

When do the carotid bodies start firing?

A

When PaO2 falls below 60-65 mmHg via the glossopharygneal nerve to increase minute ventilation

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43
Q

How is CO2 transport d in the blood?

A

As dissolved CO2, bicarbonate and carbamino compounds

Majority = bicarbonate

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44
Q

What is the mechanism by which hyperbaric oxygen works?

A

It increases PaO2 thereby increasing the oxygen content of the blood by increasing the amount dissolved in plasma

Because the amount dissolved in plasma = paO2 X .003

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45
Q

At what level of PaO2 is the saturation of oxygen 100%?

A

100 mg

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46
Q

How much oxygen do tissues at rest extract?

A

5-6 ml/dL

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47
Q

At what FiO2 and atmospheric pressure do you get sufficient O2 requirement without contribution from hemoglobin?

A

FiO2 of 100% at 3 am

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48
Q

What is Henry’s law?

A

At a constant temperature, the amount of gas dissolved in liquid is proportional to the partial pressure of the gas

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49
Q

What is Boyle’s law?

A

At a constant temperature, the volume of gas is inversely proportional to the pressure

This is how hyperbaric oxygen therapy works in air embolism

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50
Q

What mediates bradycardia?

A

Carotid sinus barorerceptor stimulation causing SNS inhibition

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51
Q

How does the carotid sinus work?

A

Afferents nerves go to glossopharygneal nerve (activated by stretch)

Activation leads to signaling to nucleus solitarius which inhibits sympathetic innervation from spinal cord and stimulates PNS to stimulate vagus nerve

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52
Q

When is the RV perfused in the cardiac cycle?

A

Diastole and systole due to the lower right heart pressures

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53
Q

What does angiotensin II do to GFR?

A

It increases it by constricting the efferent arteriole in states of hypovolemia

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54
Q

What does renin cause?

A

Cleavage of angiotensinogen to angiotensin I

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55
Q

What is myotonic dystrophy?

A

Delayed muscle relaxation after contraction

Other associations:
Gastric atony, thyroid dysfunction, cardiac conduction abnormalities, myopathy, MVP, diabetes, adrenal insufficiency

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56
Q

What are the symptoms that occur due to autonomic activity during ECT?

A

Increased ICP

Increased PSNS initially after seizure followed by a sympathetic surge

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57
Q

In myasthenia gravis, how do you need to change your succinylcholine dose?

A

It will need to be increased due to a decreased number of functional acetylcholine receptors

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58
Q

In MG, what will you need to do to your NMB dose?

A

Decrease it

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59
Q

In Lambert-Easton syndrome, what will you need to do to your succinylcholine dosing?

A

Decrease it because patients are sensitive to muscle relaxants

(Decreased Ach release so increased extrajunctional receptors due to low calcium influx all the time and therefore low Ach release)

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60
Q

How much more affinity does CO have for hemoglobin than oxygen?

A

200-300 times

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61
Q

How does CO shift the oxygen-hemoglobin dissociation curve?

A

Leftward

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62
Q

What kind of ph abnormality does CO cause?

A

Anion gap metabolic acidosis due to lactic acidosis from leftward shift of curve

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63
Q

Why is tachypnea a late sign in carbon monoxide poisoning?

A

Because the carotid bodies respond to PaO2, which is not affect in CO

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64
Q

What are the cardiac effects of CO?

A

Direct depression because CO binds to cardiac myoglobin even more than hemoglobin

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65
Q

What is PaO2 a function of?

A

Alveolar O2 (therefore FiO2, atmospheric pressure, and DLCO)

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66
Q

In what conditions is PaO2 normal?

A

Methemoglobinemia
Carbon monoxide poisoning
Severe anemia

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67
Q

What is a common pulse ox reading in methemoglobinemia?

A

85%

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68
Q

What are strong ions?

A 
Sodium
Chloride 
Potassium 
Magnesium
Calcium 
(Lactate, sulfate, ketoacids, nonesterified fatty acids)
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69
Q

What is the concept of the strong ion difference?

A

It proposes that plasma ph is determined by 3 independent factors: PCO2, SID, Atot (total plasma concentration of nonvolatile buffers)

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70
Q

What are the nonvolatile buffers in the body?

A

Albumin
Globulins
Inorganic phosphates

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71
Q

What is the strong ion differences?

A

It represents the difference between the charge of plasma strong cations (sodium, potassium, calcium magnesium) and anions

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72
Q

What is the normal strong ion difference?

A

40-44 mEq/L

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73
Q

What happens with rapid administration of normal saline?

A

Hyperchloremic non anion gap metabolic acidosis and a decrease in SID

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74
Q

What other condition can cause hyperchloremic metabolic acidosis?

A

Severe diarrhea (loss of isotonic fluid rich in bicarbonate)

Loss of bicarbonate is counteracts by an increase in chloride

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75
Q

What are the classic lab findings in SIADH?

A

Low sodium with a urine sodium greater than 20 and increased urine osmolarity, decreased plasma osmolarity

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76
Q

Why is urine sodium high in SIADH?

A

The kidney attempts to excrete the excess fluid through increased natriuresis in response to the decreased plasma osmolarity

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77
Q

What is the haldane effect?

A

The relationship between carbon dioxide dissociation curve and oxyhemoglobin

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78
Q

What is the Bohr effect?

A

The binding effect of H to Hemoglobin chains and the oxygen release and dissociation thereafter

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79
Q

What does Gs do?

A

GDP binds GTP then dissociates and stimulates adenylyl cyclase to convert ATP to cAMP which binds subunits that release subunits of protein kinase A which stimulates release of calcium from the sarcoplasmic reticulum

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80
Q

Which hormones work by Gs?

A 
Glucagon
Beta adrenergic a
Dopamine
V2
Anterior pituitary hormones
Prostacyclin can receptor that inhibits platelet aggregation
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81
Q

What does increased cAMP cause?

A 
Bronchodilation
Vasodilation
Increased contractility 
Lipolysis
Glycogenolysis
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82
Q

What does ECT do to cerebral blood flow and ICP?

A

Increases them

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83
Q

How does ECT work?

A

Delivers an electrical stimulus to induce a seizure of at least 25 seconds

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84
Q

What are the side effects of ECT?

A 
Headache
Myalgias
Status epilepticus
MI
Fractures
HTN
Long term memory loss
Bradycardia
85
Q

How is norepinephrine inactivated?

A

By degradation in the pulmonary endothelium

86
Q

What does cortisol do to electrolyte homeostasis?

A

It facilitates sodium transport
Inhibits GI sodium loss
Enhances Na/K exchange and renal potassium secretion

87
Q

How do thyroid hormones influence potassium?

A

Promote direct cellular uptake

88
Q

In a healthy young adult, plasma volume comprises approximately what percentage of extracellular volume?

89
Q

In a healthy young adult, plasma volume comprises approximately what percentage of intracellular volume?

90
Q

In a healthy young adult, interstitial volume comprises approximately what percentage?

A

80% of ECV

91
Q

What is the difference between CSW and SIADH?

A

In CSW, the patients are hypovolemic.

92
Q

What is the problem in CSW?

A

Inappropriate renal salt wasting

93
Q

What is the treatment of CSW?

A

Replacement of free water and sodium

94
Q

What factors offset the decrease in PaCO2 in acute mountain sickness?

A

Increase in CSF bicarbonate in response to reduction in OaCO2, and increase in hydrogen ions and Co2 in the CSF

This will correct after several days when the bicarbonate in CSF crosses into the blood leaving the chemoreceptors to deal with the hypoxia

95
Q

What is high altitude pulmonary edema caused by?

A

Increased pressure in the pulmonary vasculature from hypoxic vasoconstriction

96
Q

What is used as prophylaxis against high altitude pulmonary edema?

A

Nifedipine

B2 agonists

97
Q

What is hi altitude cerebral edema caused by?

A

Increased CBF due to hypoxia

98
Q

What is the treatment of high altitude cerebral edema?

A

Immediate descent and high FiO2

99
Q

How does the chloride shift work?

A

When CO2 enters the RBC, it combines with water to form carbonic acid, then dissociates to hydrogen and bicarbonate

The bicarbonate diffuses out and chloride shifts in to maintain electrical neutrality

100
Q

What Happens to the ions in RBC in lungs?

A

The oxygen causes hemoglobin to have less affinity for the hydrogen ion. It dissociates and combines with bicarbonate to form CO2 and water. (Haldane effect)

CO2 diffuses out and is exhaled

101
Q

How does helium help deliver O2 in bronchospasm?

A

Helium is less dense and has a smaller Reynolds number (less likely to be turbulent) creates more laminar flow because causes gas mixtures to be less dense

102
Q

What is th Venturi effect?

A

An increase of velocity of air through a constricted area which causes a decrease in pressure which results in more air in the lungs

103
Q

How do you treat diabetes pre operatively?

A

Tell them to take half of their usual long acting insulin or intermediate acting

104
Q

What is the hallmark of lambert Easton syndrome?

A

Muscle weakness that improves with use

105
Q

What is the hallmark of myasthenia gravis?

A

Muscle weakness worsened by usage and improved with rest

106
Q

What are the electrolyte abnormalities in Addisons?

A 
Hypercalcemia
Hyponatremia 
Hyperkalemia
Hyperchloremic metabolic acidosis 
Hypoglycemia
107
Q

Why is there hypercalcemia in Addison’s disease

A

Due to decreased GFR due to hypovolemia from adrenal insufficiency
Increased release of calcium from bone

108
Q

What is the most common cause of strider after thyroidectomy in the first 24-96 hours?

A

Hypocalcemia

109
Q

What cardiac manifestations does hypocalcemia cause?

A

Prolonged QT due to slower ventricular repolarization
Heart block
Torsades

110
Q

What is the renal mechanism for regulating plasma osmolality?

A

Vasopressin release mediated by carotid barorerceptors

111
Q

What is a thermal neutral zone?

A

The temperature range at which a naked person’s heat loss matches heat production from basal metabolic rate.

This is when heat loss occurs without sweating

112
Q

What is the thermal neutral zone for a naked newborn?

A

32-35 Celsius

113
Q

What is the thermal neutral zone for an adult?

A

26-28 Celsius

114
Q

What will happen below the thermal neutral zone?

A

Metabolic rate will increase

115
Q

What is an ASA 4?

A

Someone with a condition that is a constant threat to life

116
Q

What is an ASA 3?

A

Someone with severe systemic disease

117
Q

What is an ASA 5?

A

Someone who will die without intervention
Or organ damage has already happened

Septic shock, gangrene, uncontrolled bleeding

118
Q

What schedule of drug is ketamine?

119
Q

What are schedule 1 drugs?

A

Drugs with very high potential for abuse with no accepted medical use (heroin)

120
Q

What are hetastarches?

A

Amylopectin colloids

121
Q

What are hetastarches associated with?

A

Coagulopathy (dilution all reduction of Factor 8:C and vwf by 50-80%
Prolong PTT
Decreased platelet adhesions and clot formation by decreasing IIb/IIIa
Decreased strength of clot due to polymers moving into it
Renal failure

122
Q

What conditions are hetastarches contraindicated

A

Renal failure

Vwf

123
Q

Do tetrastarches cause more or less coagulopathy than heta

124
Q

What is the main component affected in FRC with obesity?

A

Expiratory reserve volume

125
Q

What percentage of total body weight is lean body weight?

A

80% for males

75% for females

126
Q

What percentage of total body weight is lean body weight?

A

80% for males

75% for females

127
Q

What happens to albumin in burn patients?

A

Catabolism of amino acids and proteins such as albumin occurs –> hypoalbuminemia

128
Q

What drugs need to be reduced in dosing in burn patients?

A

BZDs due to hypoalbuminemia because they are highly bound to albumin so decreasing this concentration increases their free fraction

129
Q

What drugs need to be increased in dosing in burn patients?

A

Beta blockers and local anesthetics due to less availability in the setting of hypoalbuminemia and less alpha 1 glycoprotein

130
Q

What other drugs have an increased free fraction in burn patients, but do not require reduced dosing?

A

Opioids - highly albumin bound
They do not require reduced dosing due to the amount of pain associated with burns and therefore the increased tolerance these patients develop

131
Q

What happens to the effect of NMBs in a burn patient?

A

There is a resistance due to an increase in Ach receptors including the immature isoform, increased renal excretion and decreased protein binding of the drug

132
Q

When does resistance to NMBs happen?

A

1 week after burns, peaking at 5-6 weeks.

133
Q

What happens to insulin resistance in a burn patient?

A

There is a huge catecholamine and glucagon surge in patients with burns >10% and therefore significant insulin resistance.

134
Q

How long is succinylcholine contraindicated in a burn patient?

A

From 24 hours - 1 year

135
Q

What are the major criteria for fat embolism syndrome?

A
  1. Subconjunctival or axillary petechiae
  2. Hypoxemia
  3. CNS depression
  4. Pulmonary edema
136
Q

What are the minor criteria for fat embolism syndrome?

A

Tachycardia, Hyperthermia, Decreased platelet/hct, fat globules in urine, sputum, retina, increased ESR

137
Q

What is the maximum dosing of lidocaine you can give for tumescent liposuction?

A

55 mg/kg because most of the solution is aspirated back

138
Q

How long should you wait before giving any more local anesthetic after liposuction?

A

12-18 hours

139
Q

What are the risks of tumescent liposuctin?

A

Fluid overload, LAST

140
Q

What is the biggest predictor of a difficult intubation in a morbidly obese patients?

A

A large neck circumference

141
Q

How can you minimize the likelihood of an exacerbation of MS with anesthesia?

A

maintain normothermia

The risk goes up significantly with 1 degree drop

142
Q

What is the evidence on inhalational anesthetics and pregnant providers?

A

Only Nitrous oxide affects a fetus.

There seems to be a slight increased risk of spontaneous abortion in providers.

143
Q

What happens to beta receptor sensitivity and circulating catecholamine levels with aging?

A

The catecholamine levels are elevated so beta receptor agonism is desensitized and the elderly have less of a response to stress.

144
Q

Why are the elderly more reliant on atrial kick?

A

Because diastolic dysfunction of the heart makes the passive filling phase less effective due to a decreased pressure gradient from the atrium to the ventricle since the ventricle cannot relax. They become dependent on the atrial kick for stroke volume

145
Q

Who is at risk for ulnar neuropathy?

A

Obese or thin, male, prolonged bed rest, positioning problems

146
Q

When does ulnar neuropathy show up?

A

24-72 hours postoperatively

147
Q

How long does it take for a nerve to heal?

148
Q

What do nerve conduction studies show?

A

Sensory and motor deficits

149
Q

What does it mean if a patient wakes up complaining of nerve pain?

A

The nerve damage was likely there preoperatively

150
Q

What does cricoid pressure do to LES tone?

A

Decreases it

151
Q

What does succinylcholine do to LES tone?

A

Increases it

152
Q

What drugs increase LES tone?

A

Histamine
Serotonin
Metoprolol
Cholinergics

153
Q

What nerve palsies do LMAs cause?

A

Lingual nerve, hypoglossal, recurrent laryngeal

154
Q

What are the risk factors for nerve palsies and LMAs?

A

Prolonged surgery >2-4 hours, lidocaine jelly use, nitrous oxide, overinflation of a small fitting cuff,

155
Q

What are the symptoms of lingual nerve palsy?

A

Tongue numbness, oropharyngeal swelling, difficulty phonating,

156
Q

What are the fasting rules for surgery?

A

2 hours - clear liquids
4 hours- breast milk
6 hours- light meal or human milk, formula
8 hours- real meal, fatty foods

157
Q

What drugs worsen inhalational inductions?

A

Opioids because they cause apnea

158
Q

What happens to spontaneous breathing with inhalational induction?

A

It is preserved up to a point so patients will regulate their own depth of anesthesia.

159
Q

Why is sevoflurane the choice for inhalational induction?

A

Does not cause salivation

Is not associated with Stage II excitation

160
Q

What drugs improve inhalational induction?

161
Q

What food allergies are associated with latex allergies?

A

Banana, avocado, kiwi, mango, pineapple

162
Q

Why are people who use detergents, toothpaste and shampoo at higher risk for allergic reaction to rocuronium, vec, pan?

A

Because these products contain quaternary ammonium ions that resemble the aminosteroid NMBs

163
Q

What is bone cement implantation syndrome

A

Hypoxia
Hypotension
Cardiac arrythmias
Increased pulmonary vascular resistance

164
Q

What are the grades of bone cement implantation syndrome?

A

Grade 1: SpO2 < 94% or hypotension
Grade 2: SpO2 < 88% or SBP fall >40%, unexpected LOC
Grade 3: Cardiac arrest

165
Q

What conditions have to be met for PPV to be most accurate?

A
  1. Controlled ventilation
  2. Tidal volumes of 7-8ml/Kg (IBW)
  3. No PEEP
  4. No cardiac arrythmias
  5. No big changes in chest or lung compliance (laparoscopic procedures, open chest)
166
Q

What is the pathophysiology of bone cement implantation syndrome?

A

Increased intramedullary pressure leading to embolization of fat, bone, cement, platelets, fibrin, air

167
Q

What happens in phase 0 of a muscle depolarization?

A

Influx of sodium

168
Q

What happens in phase 1 of muscle depol

A

Transient efflux of potassium

169
Q

What is phase 2 of muscle depol?

A

Net influx of calcium which causes plateau

170
Q

What is phase 3 of muscle depol?

A

Significant efflux of K

171
Q

What does epidural anesthesia do to pulmonary mechanics?

A

Can decrease peak expiratory pressure by 40%

Decreases FEV1 and vital capacity by 10% in lumbar or low thoracic. High thoracic causes 20-30%

172
Q

Why is peak expiratory pressure affected in epidural anesthesia?

A

Because it relies on abdominal muscles primarily

173
Q

How does a variable bypass chamber work?

A

A carrier gas goes through the chamber and picks up the anesthetic vapor.

A certain percentage of volatile is delivered to the patient depending on how much fresh gas flow passes through the vaporizer chamber

174
Q

What causes bradycardia in intrathecal injection?

A

High baseline vagal tone
Anesthetic levels above T5
Decreased preload

175
Q

Why does decreased cardiac preload cause bradycardia?

A

Decreased stretch of myocardium so intrinsic depolarization of SA node slows

176
Q

What is the Bainbridge reflex?

A

Stretching of the myocardium causes increased heart rate

177
Q

What happens in digitalis toxicity with hypokalemia?

A

There is reduced binding to potassium ions with the Na-K-ATPase pump so it causes worsened pump inhibition due to digitalis

178
Q

What may happen with digitalis in the setting of hypomagnesemia or hypercalcemia?

A

Toxic levels of intracellular calcium leading to ventricular arrhythmias

179
Q

In what surgeries should ASA be held?

A 
Intracranial
Middle ear
Posterior eye
Intra medullary spine 
Prostate
180
Q

Which surgeries should ASA be continued?

A

Major vascular

181
Q

When do the most serious cases of CO2 embolism happen?

A

In the beginning of the procedure due to the Veress needle being put into a vein or organ

182
Q

Will CO2 emboli expand if the patient is in N2O?

A

No because CO2 is more soluble than nitrous

183
Q

What are the four sites known to be reflective of core temperature?

A

Esophageal
Tympanic
Pulmonary artery
Nasopharyngeal

184
Q

What 2 things can cause an acute and excessive increase in PaCO2 and EtCO2 with rapid administration?

A

Dextrose

Bicarbonate

185
Q

What is Hoffman elimination?

A

A quaternary ammonium group is converted to a tertiary amine by cleavage of a carbon-nitrogen bond,

186
Q

What increases the speed of Hoffman elimination?

A

Increased ph and increased temperature

187
Q

What P450 enzymes does St. John’s Wort induce?

A

3A4 and 2C9

2C9: NSAIDs
3A4: alfentanil, midazolam, lidocaine, oral contraceptives

188
Q

What factors stimulate the release of vasopressin?

A

Pain, nausea, hypoglycemia, increased plasma osmolality, stress, pregnancy, nicotine

189
Q

What factors inhibit release of vasopressin?

A

Cortisol
Increased circulating volume
Caffeine
Hypo-osmolality

190
Q

How does vasopressin stimulate vasoconstriction?

A

By activating G protein and phospholipase C –> release calcium from SR

191
Q

What is the half life of vasopressin?

A

15-20 minutes

192
Q

How does vasopressin stimulate water resorption?

A

Increasing intracellular levels of cAMP and activating protein kinase A

193
Q

Why are burn patients resistant to NMBs?

A

Because they have an up regulation of receptors and higher protein binding so there is less free drug to bind more receptors

194
Q

Why do burn patients need a decreased dose of miva curium?

A

Because they have less pseudocholinesterase and this is how miva curium is broken down

195
Q

What nerve needs to be blocked for lateral bladder wall tumor?

A

Obturator to avoid the jerk reflex

196
Q

What influences spread of local anesthetic in epidural?

A

Age: more spread due to more dura permeability, more patency since less fat in the space, more compliance
PEEP
Volume of local
Mass of local

197
Q

What is anterior spinal cord syndrome?

A

Loss of motor, pain, temperature

Proprioceptiom is intact

198
Q

What type of patients are at higher risk for new or worsened nerve injury after spinal anesthetic?

A

Patients with space occupying lesions or spinal stenosis

199
Q

Which nerves are the fastest conducting for pain?

200
Q

What imaging should be used to diagnose a retained epidural catheter?

201
Q

What do you do if an epidural catheter is difficult to remove?

A

Flex the patient
Inject saline into the catheter
Used a tongue blade and have patient move around some

202
Q

What problems can you have with administering anesthesia to patients with ankylosing spondylitis?

A

Difficult intubation due to inability to move their neck
Difficult ventilation due to pulmonary fibrosis
Epidural hematoma due to multiple attempts and platelet dysfunction due to NSAID use

203
Q

What should you avoid using if a patient is on bleomycin?

A

High FiO2 because the pulmonary toxicity associated with bleomycin depends on this

204
Q

What chemotherapy drugs affect the peripheral nervous system?

A

Vincristine, cisplatin

205
Q

What is the biggest predictor for difficult intubation in morbid obesity?

A

Increased neck circumference

206
Q

When does the most amount of heat loss happen in the OR?

A

During the first hour of anesthesia

207
Q

What are the consequences of hypothermia?

A

Coagulation defects
Wound infection/healing
Impaired drug metabolism
MI due to shivering and increased oxygen consumption

208
Q

What should the operating room temperature be to maintain normothermia?

A

23-25 degree Celsius

Anesthesia MM/TL (36 decks)

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