1
Q
What are the 5 main goals of anesthesia?
A
Amnesia, paralysis, sedation, analgesia, and reflex control.
2
Q
What does amnesia mean in anesthesia?
A
The patient does not remember the procedure.
3
Q
What does paralysis mean in anesthesia?
A
The patient does not move during the procedure.
4
Q
What does sedation mean in anesthesia?
A
The patient is calm and less aware.
5
Q
What does analgesia mean in anesthesia?
A
The patient does not feel pain.
6
Q
Why is reflex control important during anesthesia?
A
Reflexes can interfere with the procedure.
7
Q
What determines how far a patient progresses through the stages of anesthesia?
A
The dose and amount of anesthetic administered.
8
Q
What happens in Stage I of anesthesia?
A
Analgesia occurs; the patient is conscious and can still communicate.
9
Q
Is the patient conscious in Stage I of anesthesia?
A
Yes.
10
Q
What is Stage II of anesthesia called?
A
Excitement or delirium stage.
11
Q
What is the patient like in Stage II of anesthesia?
A
Combative, delirious, and in an excited state.
12
Q
During which stage of anesthesia is airway management especially important?
A
Stage II.
13
Q
Why is the airway a major concern in Stage II?
A
Airway stimulation can trigger complications such as bronchoconstriction or severe airway issues.
14
Q
Why should suctioning be done carefully in Stage II?
A
It can overstimulate the airway.
15
Q
Why should clinicians be careful with what they say during Stage II?
A
The patient may still hear or later remember comments.
16
Q
What happens in Stage III of anesthesia?
A
The patient is unconscious, without pain, and ready for surgery.
17
Q
During which stage is surgery ideally performed?
A
Stage III.
18
Q
What happens in Stage IV of anesthesia?
A
Medullary paralysis from anesthetic overdose.
19
Q
Why is Stage IV dangerous?
A
It can cause respiratory/cardiovascular collapse and death.
20
Q
Which stage of anesthesia represents overdose?
A
Stage IV.
21
Q
What is the main mechanism of action of topical and neuraxial anesthetics?
A
They block sodium channels.
22
Q
Why does blocking sodium channels reduce pain?
A
It prevents depolarization and propagation of pain signals.
23
Q
What ion entering the cell is required for depolarization?
A
Sodium.
24
Q
What kind of drugs are local anesthetics pharmacologically?
A
Sodium channel blockers.
25
What are the 2 major classes of local anesthetics?
Amides and esters.
26
What is the classic naming clue for many amide local anesthetics?
They usually have two “i” letters in the name.
27
What is the classic naming clue for many ester local anesthetics?
They usually have one “i” in the name.
28
Which class includes lidocaine?
Amides.
29
Which class of local anesthetics is metabolized by the liver?
Amides.
30
Which class of local anesthetics is metabolized by plasma pseudocholinesterase?
Esters.
31
Which local anesthetic class is more associated with allergic reactions?
Esters.
32
Why are esters more likely to cause allergic reactions?
They are metabolized to PABA-like compounds.
33
True or false: Amides are metabolized by the kidney.
False. Amides are primarily metabolized by the liver.
34
True or false: Esters are primarily metabolized by the liver.
False. Esters are primarily metabolized by plasma pseudocholinesterase.
35
Which organ function matters most for safe metabolism of amide local anesthetics?
Liver function.
36
Which enzyme is important for ester local anesthetic metabolism?
Plasma pseudocholinesterase.
37
Why is epinephrine often added to local anesthetics like lidocaine?
To cause vasoconstriction and keep the anesthetic at the injection site longer.
38
How does epinephrine prolong local anesthetic action?
It decreases systemic absorption by vasoconstriction.
39
What is one benefit of adding epinephrine besides prolonging effect?
It reduces bleeding in the area.
40
Why does reduced absorption of local anesthetic matter clinically?
It prolongs local effect and lowers systemic toxicity risk.
41
In which body areas should epinephrine be avoided with local anesthetics?
Areas with end-arterial or limited blood supply, such as fingers, toes, nose, penis, and ears.
42
Why should epinephrine be avoided in end-arterial areas?
It can cause ischemia and tissue necrosis.
43
What complication can occur if too much epinephrine is used in the fingers?
Distal ischemia and necrosis.
44
Why is the nose considered a risky site for epinephrine-containing local anesthetic?
Its distal blood supply can be compromised by vasoconstriction.
45
A patient becomes combative and delirious while going under anesthesia. What stage are they in?
Stage II.
46
During induction, when is overstimulation of the airway most dangerous?
Stage II of anesthesia.
47
A patient is unconscious, pain-free, and ready for incision. What stage are they in?
Stage III.
48
A patient under anesthesia develops signs of medullary depression from overdose. What stage is this?
Stage IV.
49
What is the key pharmacologic action of local anesthetics?
Block voltage-gated sodium channels.
50
Why add epinephrine to lidocaine?
To keep it local longer by vasoconstriction and reduce bleeding.
51
When should epinephrine-containing local anesthetic be avoided?
In areas with poor collateral blood supply.
52
Stage I anesthesia = ?
Analgesia with consciousness intact.
53
Stage II anesthesia = ?
Excitement/delirium.
54
Stage III anesthesia = ?
Surgical anesthesia.
55
Stage IV anesthesia = ?
Medullary paralysis/overdose.
56
Local anesthetics block what?
Voltage-gated sodium channels.
57
Amides metabolism = ?
Liver.
58
Esters metabolism = ?
Plasma pseudocholinesterase.
59
Epinephrine added to local anesthetic does what?
Vasoconstriction, less absorption, longer effect.
60
Epinephrine should be avoided where?
Fingers, toes, nose, penis, ears.
61
In what order do local anesthetics classically block sensory modalities?
Pain → temperature → touch → pressure.
62
Which sensation is lost first with local anesthetics?
Pain.
63
Which sensation is lost after pain with local anesthetics?
Temperature.
64
Which sensation is lost later than pain and temperature with local anesthetics?
Touch.
65
Which sensation is lost last in the sequence described for local anesthetic blockade?
Pressure.
66
What is neuraxial anesthesia?
Anesthesia delivered around the spinal cord or nerve roots, including epidural and spinal anesthesia.
67
What are the 2 main types of neuraxial anesthesia?
Epidural anesthesia and spinal anesthesia.
68
What is epidural anesthesia?
Injection or infusion of anesthetic into the epidural space without piercing the dura.
69
What is spinal anesthesia?
Injection of anesthetic into the subarachnoid space after piercing the dura.
70
Which neuraxial technique pierces the dura?
Spinal anesthesia.
71
Which neuraxial technique usually uses a catheter for continuous infusion?
Epidural anesthesia.
72
In epidural anesthesia, is the dura pierced?
No.
73
In spinal anesthesia, where is the anesthetic placed?
Into CSF in the subarachnoid space.
74
Which topical anesthetic is classically associated with methemoglobinemia?
Benzocaine.
75
What is the treatment for methemoglobinemia?
Methylene blue.
76
What oxidation state is iron in during methemoglobinemia?
Ferric iron, Fe3+.
77
Why is Fe3+ in methemoglobin a problem?
It cannot bind oxygen effectively.
78
What happens to PaO2 in methemoglobinemia?
PaO2 is usually normal.
79
What happens to oxygen saturation in methemoglobinemia?
Oxygen saturation is decreased.
80
Why can PaO2 be normal in methemoglobinemia?
Because dissolved oxygen in blood is normal; the problem is impaired oxygen binding to hemoglobin.
81
What happens to hemoglobin concentration in methemoglobinemia?
Hemoglobin concentration may be normal.
82
What is the key pathophysiology of methemoglobinemia?
Oxygen reaches the blood, but hemoglobin iron cannot bind it effectively.
83
Is benzocaine-induced methemoglobinemia inherited or acquired?
Acquired.
84
What clue in a vignette should make you think of benzocaine exposure?
Recent use of a topical anesthetic for a minor procedure.
85
What minor procedures may involve topical anesthetics and trigger methemoglobinemia questions?
Endoscopy, colonoscopy, hemorrhoid treatment, circumcision, and similar minor procedures.
86
A patient has cyanosis, normal PaO2, and low oxygen saturation after benzocaine exposure. What is the diagnosis?
Methemoglobinemia.
87
A patient develops methemoglobinemia after topical anesthetic use. What is the best next step?
Give methylene blue.
88
What can happen if local anesthetic is accidentally injected into a blood vessel during neuraxial anesthesia?
Local anesthetic systemic toxicity.
89
What is local anesthetic systemic toxicity?
Systemic toxic effects from anesthetic entering the bloodstream.
90
What is often the earliest symptom of local anesthetic systemic toxicity?
Metallic taste.
91
What other early CNS symptoms can occur in local anesthetic systemic toxicity?
Tinnitus and seizures.
92
Why do early symptoms of local anesthetic toxicity initially look excitatory?
Because inhibitory pathways are blocked first.
93
What happens after inhibitory pathways are blocked in local anesthetic toxicity?
Excitatory pathways are also blocked, causing CNS and cardiovascular depression.
94
What severe findings may occur in later local anesthetic toxicity?
Hypotension, coma, cardiovascular collapse.
95
What is the antidotal treatment for severe local anesthetic systemic toxicity?
Lipid emulsion therapy.
96
How does lipid emulsion therapy help in local anesthetic toxicity?
It acts as a lipid sink that binds lipophilic anesthetic drug in the bloodstream.
97
Why does lipid emulsion therapy work for local anesthetic toxicity?
Many local anesthetics are highly lipophilic.
98
Besides lipid emulsion therapy, what supportive measures may be needed in local anesthetic toxicity?
Fluids, cardiovascular support, and inotropes if needed.
99
A patient develops metallic taste, tinnitus, and seizures after anesthetic injection. What is the diagnosis?
Local anesthetic systemic toxicity.
100
A patient becomes hypotensive and comatose after intravascular injection of local anesthetic. What is the next treatment?
Lipid emulsion therapy plus supportive care.
101
What is a post-dural puncture headache caused by?
Leakage of CSF after dural puncture.
102
What is the classic positional feature of a post-dural puncture headache?
It worsens when sitting or standing and improves when supine.
103
Why is post-dural puncture headache positional?
Loss of CSF causes intracranial support to decrease, making upright posture worsen symptoms.
104
After neuraxial anesthesia, a patient develops severe headache when sitting up. What is the diagnosis?
Post-dural puncture headache.
105
What is the initial conservative treatment for post-dural puncture headache?
Supine rest, hydration, analgesics, and caffeine.
106
Why is caffeine used in post-dural puncture headache?
It helps by causing cerebral vasoconstriction and can reduce symptoms.
107
What analgesic may be used for post-dural puncture headache?
Acetaminophen.
108
What is the definitive treatment for persistent severe post-dural puncture headache?
Epidural blood patch.
109
How is an epidural blood patch performed?
The patient’s own blood is injected into the epidural space near the puncture site.
110
How does an epidural blood patch work?
It seals the CSF leak.
111
When is an epidural blood patch considered?
When symptoms are severe or persist despite conservative treatment.
112
Why does injecting autologous blood into the epidural space help?
It forms a patch that closes the leak and restores CSF pressure.
113
A patient has severe headache and nausea 1 day after spinal anesthesia, worse upright. Best next step if conservative therapy fails?
Epidural blood patch.
114
What is the most likely diagnosis in a patient with normal PaO2 but low O2 saturation after benzocaine use?
Methemoglobinemia.
115
What is the antidote for benzocaine-induced methemoglobinemia?
Methylene blue.
116
What is the earliest classic complaint in local anesthetic systemic toxicity?
Metallic taste.
117
What neurologic symptoms may follow early local anesthetic toxicity?
Tinnitus and seizures.
118
Why are seizures seen early in local anesthetic toxicity?
Inhibitory pathways are blocked first.
119
What dangerous cardiovascular finding may occur later in local anesthetic toxicity?
Hypotension.
120
Best treatment for severe systemic toxicity from local anesthetic?
Lipid emulsion therapy.
121
What is the key positional clue for post-dural puncture headache?
Worse upright, better lying flat.
122
Best definitive treatment for persistent post-dural puncture headache?
Epidural blood patch.
123
First sensation lost with local anesthetic?
Pain.
124
Benzocaine complication?
Methemoglobinemia.
125
Methemoglobinemia treatment?
Methylene blue.
126
Methemoglobinemia PaO2?
Normal.
127
Methemoglobinemia O2 saturation?
Low.
128
Epidural vs spinal: which pierces dura?
Spinal.
129
Earliest sign of local anesthetic systemic toxicity?
Metallic taste.
130
Antidote for severe local anesthetic toxicity?
Lipid emulsion therapy.
131
Post-dural puncture headache cause?
CSF leak.
132
Post-dural puncture headache definitive treatment?
Epidural blood patch.
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