Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Pharmacology Exam 3 > Inhaled Anesthetics 2 (exam 3) > Flashcards

Inhaled Anesthetics 2 (exam 3) Flashcards

1
Q

Name (4) jobs of the Anesthesia Circuit

A
  1. Delivers Oxygen
  2. Delivered inhaled Drugs
  3. Maintains Temperature/humidity (body temp)
  4. Removes carbon dioxide and exhaled drugs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Name (3) Type of Anesthesia Circuits

A
  • Rebreathing (Bain)
  • Non-breathing (self-inflating BVM)
  • Circle Systems
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Name this circuit

A

Bain Circuit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Does the Bain Circuit allow you to adjust PEEP?

A
  • No
  • only contains tubing, bag, oxygen and 1 escape valve
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Name this circuit

A
  • Non-rebreathing (Ambu or BVM)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Does the Ambu allow you to adjust PEEP?

A
  • Yes
  • PEEP, Expiratory valve, pressure release valves.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Name the (6) parts of the Circle System

A
  1. Fresh gas inlet
  2. Inspiratory and Expiratory limbs
  3. Reservoir bag
  4. CO2 Absorbent
  5. One way valve
  6. Y piece
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Inhalation Anesthesia: High Flow

A
  • FGF exceeds minute ventilation
  • Rapid changes in anesthetics
  • Prevents Rebreathing
  • Wasteful
  • Cools/dries delivered volume
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Inhalation Anesthesia: Low Flow

A
  • FGF less than Vm
  • Low Cost
  • Less Cooling/drying
  • Very slow changes in anestheic
  • Concerned with Compound A production
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Name (3) factors of the price of anesthetics

A
  • Cost of liquid/ml
  • Volume % of anesthetic delivered ( Potency)
  • FGF Rate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Pathology to Relax airway smooth muscle

A
  • Block Voltage-gated Ca++
  • Depleted Ca++ in SR
  • Requires intact epithelium
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

If the endolthelium is damaged or inflammed, will bronchodilation occur?

A
  • No
  • Requires an intact endothelium
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Bronchodilation without bronchospasm

A
  • Baseline pulmonary resitance unchanged by 1-2 MAC
  • Need Histamine release or vagal afferent stimulation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Name (3) Volatiles that cause Bronchodilation with bronchospasm

A
  • Sevoflurane>Isoflurance
  • Desflurane may worsen, especially in smokers d/t pungency/irritation.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Name (4) Risk Factors for bronchospasm with bronchodilation

A
  1. COPD
  2. Cough response w/ ETT
  3. age <10
  4. URI
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q
A

Respiratory Resistance Comparison
* More spastic and narrowed
* Thiopental is bad
* Sevoflurane is good

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How Volatiles affect Neuromuscular

A
  1. Dose dependent skeletal muscle relaxation
  2. Potentiate depolarizing and non-depolarizing NMBDs.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Name (1) Volatile that does not have a relaxant effect on skeletal muscles.

A

Nitrous Oxide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How do volatiles potentiate depolarizing and non-depolarizing NMBD.

A
  • nAch receptors at NMJ
  • Enhance glycine at spinal cord
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Define Ischemic Preconditioning with Volatiles

A
  • Brief periods of ischemia prior to longer periods.
  • Mediated by adenosine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How does Adenosine mediate Ischemic Preconditioning?

A
  • Increases protein Kinase C activity
  • Phosphorylates ATP sensitive K Channels
  • Production at reactive oxygen species (ROS)
  • Better regulated vascular tone
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What dose of MAC can ischemic preconditions occur?

A
  • 0.25 MAC
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Name (3) “ reperfusion injuries” Volatile Ischemia precondition can prevent.

A
  1. Cardiac dysrhythemias
  2. Contractile dysfunction
  3. Clinically apparent in delaying MI for PTCA , CABG
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Volatile Effects on CNS activity

A
  • Dose Dependent ⬇️ CMRO2 and cerebral activity
  • Iso = Sevo = Des
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
At what MAC does wakefulness change to unconciousness?
* 0.4 MAC
26
At what MAC does burst suppression occur right before brain death?
* 1.5 MAC
27
At what MAC does does electrical silence or brain death occur?
* 2 MAC
28
Name (3) Volatiles that have anticonvulsant activity
1. Des 2. Iso 3. Sevo
29
At what dose will volatiles have anticonvulsant activity?
* At high concentrations and with Hypocarbia
30
Name (1) Volatile that has Proconvulsant activity
* Enflurane
31
At what dose and PaCO2 will Enflurance have Proconvulsant activity?
* > 2 MAC * PaCO2 < 30 mmHg
32
Volatile Evoke Potential (2) Types
* SSEP's (Somatosensory Evoked Potential) * MEP (Motor Evoked Potential)
33
Define Evoked Potential
* Dose related ⬇️amplitude and ⬆️ latency (0.5-1.5 MAC)
34
What dose of Volatile will you use for evoked potentials? Why?
* Nitrous 60% and >0.5 MAC * Tell difference between surgeon induced and anesthesia induced.
35
Do Volatiles effect Cerebral Blood Flow?
* Yes * Dose Dependent
36
Cerebral Blood Flow:Dose Dependent
* ⬆️ CBF due to decreased cerebral vascular resistance * May increase ICP
37
Dose and onset of Volatile effect of Cerebral Blood Flow.
* > 0.6 MAC * Occurs within minutes despite lack of BP changes
38
Does Iso or Des cause more changes in cerebral blood flow?
* Neither. * They are equal
39
* What volatile is a potent vasodilator, but unable to give at high enough doses?
* Nitrous * give < 1 MAC
40
What Volatile is the worst at decreasing cerebral blood flow?
* halothane
41
Auto Regulation
* Halothane lost by 0.5 MAC * Sevo preserves to 1 MAC * Iso and Des lost 0.5 - 1.5 MAC
42
What parallel increases in Cerebral Blood Flow with volatiles?
* ICP
43
What patients are most at risk for an increase in ICP?
* Patient with space- occupying lesions
44
How can you oppose ICP?
* Hyperventilation
45
Dose at which volatiles increase ICP? How much of an increase in ICP?
* Onset > 0.8 MAC * ICP increases 7 mmHg
46
Pathology of Respiratory Depression with Volatiles
* Direct depression of medullary Ventilatory center * Interfere with intercostal muscle (Diaphrams descends, chest wall collapses inward.) * Rate change insuffiencent to maintain Vm or PaCO2
47
At what dose do volatiles cause apnea?
* 1.5 - 2.0 MAC
48
Name (2) Ventilatory Response with Volatiles
* Blunt hypoxic response * Blunt hypercarbia response
49
What mediates the Blunt hypoxic response?
* Carotid bodies
50
What MAC dose causes a 50 - 70% depression for blunt hypoxic response
*0.1 MAC
51
What MAC dose causes a 100% depression for blunt hypoxic response
* 1.1 MAC
52
What Volatiles can cause a Blunt hypoxic response
* All volatiles * including Nitrous
53
For how long can the blunt hypoxic response occur with volatiles
* Several hours post-op
54
What mediates the blunt hypercarbic response to volatiles?
* Dose dependent
55
What volatile has no blunt hypercarbic response?
* Nitrous-- does not increase PaCO2 * substitute it for part of MAC: less depression.
56
Which volatiles will cause an increase in CO2?
* All
57
What is Hypoxic Pulmonary Vasoconstriction?
* Normal contration of pulmonary smooth muscle * Beneficial means of diverting blood flow * Can occure with volatiles
58
When is Hypoxic Pulmonary Vasoconstriction the most concerning?
* 1 lung ventilation
59
Hypoxic Pulmonary Vasoconstriction: Beneficial means of diverting blood flow
* Optimize V/Q * 5 minutes .... regional blood flow is 1/2 * Maximal response lasts 2-4 hours
60
Hypoxic Pulmonary Vascoconstriction with Volatiles
* Dose dependent decrease in response * 50% depression at 2 MAC
61
Volatiles Cardiovascular Depression: MAP
* Direct myocardial depression * Dose Dependent * Greater significance in diseased hearts w/ already altered contractility.
62
Pathology on how volatiles have a direct myocardial depression
* Alters Ca++ entry and SR function
63
Volatiles Dose Dependent cardiovascular depression:MAP
1. ↓ contractility, SV and CO (more with Halothane) 2. ↓MAP primarily due to ↓SVR
64
Name (1) volatile that has no cardiac depression
Nitrous
65
Volatiles effect on Heart Rate
* Dose dependent * Confounding variable
66
At what dose does Sevo affect heart rate?
* >1.5 MAC
67
At what dose does Iso and Desflurane affect heart rate?
* ISO: Lower concentrations * Desflurane: over-pressurization
68
Name (4) Confounding Variables that can affect HR with volatiles
* Anxiety * Opioids * Beta-blockade * Vagolytic administration(glycopyrolate)
69
How do volatiles affect cardiac output?
* Dose dependent ⬇️ CO (offset by mild ⬆️ in HR for most volatiles) * Coronary steal
70
Name (1) Volatile that does NOT decrease CO
* Nitrous * sympathomimetic…mild increase CO
71
Define Coronary steal
* rob ischemic vessels and give to normal vessels
72
How do volatiles cause Coronary steal?
* d/t coronary vasodilation * Preferentially in 20-50 micrometer vessels * Not clinically significant
73
* Halothane - huge decline in CI * Iso - small decline * Des and Sevo level off and increase slightly
74
Name (1) cardiac dysrhythmia that occurs because of volatiles
* Increased risk of Torsades's * d/t Prolonged QT interval in healthy patients * Inhibition of K current
75
Name (1) volatile that has miminal proarrythmic effect
Nitrous
76
77
Cardiac dysrhythmias: Ablation studies w/ ISO and SEVO
* Iso ↑ refractoriness of accessory paths…..difficult interpretation * Sevo no effect…acceptable for ablation
78
Immune Effects of Volatiles
* Neuroendocrine stress response
79
Define the Neuroendocrine stress response of Volatiles
* ANS and HPA activated * Perioperative surge in catecholamines, ACTH, cortisol * Suppression of monocytes, macrophages, and T-cells
80
Immune response: GA compared to neuraxial
* Increase metastasis * increased mortality
81
Volatiles effect on Hepatic Blood Flow: Total Hepatic Blood Flow
Maintained
82
Volatiles effect on Hepatic Blood Flow: Hepatic Artery flow
Maintained
83
Volatiles effect on Hepatic Blood Flow: Portal Vein flow
* Increase d/t volatiles vasodilation * 1-1.5 MAC
84
Name (1) Volatiles that decreases hepatic flow
* Halothane * decrease hepatic flow --> decrease oxygen delivery
85
Hepatotoxicity definition and consequences
* Inadequate oxygenation of hepatocytes * ↓ blood flow, enzyme induction…↑ O2 demand
86
Name (1) Concern of hepatotoxicity
* preexisting liver disease
87
Hepatotoxicity: Type 1
* 20% of patients * 1-2 weeks after exposure * Direct toxic effect or free radical effect * Nausea, lethargy, fever
88
Hepatotoxicity: Type 2
* Less commone * Immune- mediated response against hepatocytes: eosinophilia, fever * Prior exposure * 1 month after exposure * High mortality: acute hepatitis, hepatic necrosis
89
Name (3) volatiles that are oxidized to acetyl halides metabolites. What enzyme?
* Enflurane> isoflurane> desflurane * oxidized by P450
90
What can acetyl halides metabolites cause?
* antibody reaction
91
Metabolism to acetyl halide is most common in patients......
* sensitized by Halothane or Enflurane
92
Sevoflurance can be metabolized into.....
* vinyl halide
93
Is vinyl halide capable of stimulating antibody formation?
No
94
Name the Renal effects of Volatiles
* Dose dependent * ↓ RBF, GFR and U/O * Not r/t to vasopressin release but CO
95
How can the Renal effects be counteracted?
* Preoperatively hydrate
96
What cause nephrotoxity with volatiles?
* Fluoride toxicity (metabolites)
97
Name (3) s/s of Nephrotoxicity
* Hyperosmolarity * Hypernatremia * increased creatinine
98
Why are we not concerned about nephrotoxicity in newer volatiles
* Newer volatiles have lower solubility * are exhaled prior to being metabolized and eliminated renally
99
Name (1) Volatile that causes nephrotoxicity
* Methoxyflurane * 70% metabolized * 1st noticed * Removed from market
100
Compound A formation
* Carbon dioxide absorbents and Sevo metabolism * ↑↑ levels of potassium and sodium hydroxide… Fluoromethyl-2,2-difluro-1-vinyl ether (compound A)
101
Why are we not worried about Compound A today?
* Absorbers are 75% or > calcium hydroxide
102
Sevoflurane and fire
* Reacts chemically with desiccated absorbent * Produces methanol and formaldehyde * Reaction→heat→faster reaction→more heat * to counteract this, additional water is added to Sevo
103
If the absorbent canister is hot, what does this indicate?
* absorbent is unable to absorb CO2 * Switch out the canister
104
When should a patient that has the possibility of Maliganant Hyperthermia be scheduled?
* 1st case of the day * pre-run machines to scrub of volatiles
105
Malignant Hyperthermia
* Uncommon, inherited, genetic
106
How is MH diagnosised?
* Caffeine contracture test
107
Triggers of MH
* All volatiles * Succinylcholine
108
MH: hypermetabolic state of skeletal muscle
* Excessive Release of Ca++ * Muscle Rigiditiy * Rhabdomyolysis
109
MH: Symptoms
* ↑ body temp, CO2 production, O2 consumption * 80% mortality untreated
110
Treatment of MH
* Dantrolene -- blocks intracellular Ca++ release * Supportive care of rhabdomylosis
111
Name the volatiles that cause PONV
* All
112
Name the (2) triggering agents with GA that can cause PONV
* Volatiles and opioids * 25 - 30 %
113
What volatile at >0.5 MAC causes PONV in all patients
* Nitrous
114
Name (3) Metabolic effects of Nitrous oxide
* B12 deficiency * Megaloblastic bone marrow suppression * Increases plasma homocysteine levels
115
Nitrous Oxide: B12 deficiency
* Oxidizes cobalt ion in B12 * inhibits methionine synthase * inhibits DNA synthesis
116
Name (2) adverse effects of Nitrous oxide B12 deficiency
* Developing fetus at risk * Scavenging systems
117
Nitrous Oxide: Megaloblastic bone marrow suppression
* After 24 hours of exposure * Repeated exposures<3 day intervals cumulative
118
Nitrous oxide: Increases Plasma homocysteine levels
1. Associated with low B vitamins and > levels of atherosclerosis 2. ↑ perioperative myocardial events
119
Obstetric Effects of Volatiles
* Dose-dependent (0.5-1.0 MAC) * ↓ uterine smooth muscle contractility * Useful with retained placenta * Worsen blood loss in uterine atony
120
Obstetic Effects: Nitrous
* No effect on contractility * Increase analgesia without opiods/BZD depression
121
Halothane
* Halogenated alkane * Compatible with inhalation induction * Lower risk of N/V * non-flammable
122
Halothane Concerns
* Catecholamine-induced arrhythmias * Occasional hepatic necrosis * Pediatric brady-arrhythmias * Decomposition to HCL acid….thymol preservative added
123
Halothane Potency and Solubility
* High potency * Intermediated solubility
124
Isoflurane (Forane)
* An isomer of enflurane * Highly pungent * Expensive to purify
125
Isoflurane Potency and solubility
* Highly potent * Intermediate solubility
126
Isoflurane Stability
* No deterioritation after 5 years
127
Isoflurance (Forane) metabolism
* Resistant to metabolism * Unlikely organ toxicity
128
Desflurance (Suprane)
* Fluorinated methyl ethyl ether * Identical to isoflurane (F sub for Cl-) * ↓ solubility and potency * ↑ vapor pressure
129
What does Desflurance (Suprane) require on the anesthesia machine?
* Special vaporizer (heated)
130
Desflurance Pungent
* The most pungent * Coughing, salivationm breathholding * Laryngospasm (w/ > 6% FI)
131
Desflurane (Suprane) Over-pressurizing causes
SNS stimulation
132
Desflurance (Suprane) degradation
* Will degrade to CO (Carbon Monoxide) if absorbent dehydrated * Desflurane > Enflurane > Isoflurane > Sevoflurane (trivial)
133
Sevoflurane (ultane)
* Fluorinated methyl isopropyl ether * Low solubility
134
Sevoflurance (ultane): Pungent
* Sweet smelling; not pungent * Least airway irritation of modern volatiles
135
Name the Volatile that has the least airway irritation of modern volatiles
Sevoflurane
136
Sevoflurane (ultane): Metabolism
* Inorganic fluride * Least like to form CO * Compound A --disproved
137
Name the Volatile of choice for ↑ ICP
* Sevo
138
Sevoflurane: Cerbral vasodilation
* DOC for ↑ ICP * Suppresses lidocaine induced seizure activity
139
Nitrous Oxide
* Usually not sole anesthetic * Low solubility, low potency * does not produce skeletal muscle relaxation * Can't delived 1 MAC
140
Odor of Nitrous
* Sweet smelling/odorless
141
Nitrous + spinals
* Nitrous is a good to supplement with spinals when the spinal is wearing off.
142
Positives of Nitrous
* good analgesia * 2nd gas effect
143
Negative of Nitrous
* N/V > 50% (about 0.5 MAC) * ↑ PVR
144
What can nitrous do in neonates
* May increase right-to-left shunt * jeopardize arterial oxygenation

Pharmacology Exam 3 (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions