General Anesthetics I Flashcards

1
Q

What is anesthesia

A

a state where no movement occurs in response to what should be painful
the patient has lost consiousness

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

absence of memory during anesthesia

A

amnesia

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

inability to interepret, respond to and remember pain

A

Analgesia

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

Analgesia is

A

inable to interpret, respond to and remember pain

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

During anesthesia you are

A

immobile to respond to noxious stimuli and you do not activate autonomic responses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Potency is usually measured by determination of the concentration of anesthetic that

A

prevents movement in response to pain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

The ‘dose’ of anestetic that prevents movement in:

A

in response to pain in 50% of the patients

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

the dose of a gas is directly related to and determined by :

A

conc in alveolus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What quantifies anesthetic potency in inhaled anesthetics?

A

minimal alveolar concentration (MAC) that prevents movement in 50% of pts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Benefits of MAC as measure of potency

A

Can be continuously monitored by measuring end-tidal anesthetic concentration
Provides a direct correlate to anesthetic concentration at the site of action in CNS
Simple to measure end-point (lack of movement)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How do we measure potency for intravenously administered anesthetics

A

usually use free plasma concentration that produces loss of response to surgical incision in 50% of subjects as an index of potency.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Common effects shared by all anesthetics include

A

membrane hyperpolarization and effects on synaptic function; such that inhibitory neurotransmission is increased and excitatory neurotransmission is reduced.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Likely targets of anesthetics

A

GABAa
NMDA
other channels and membrane proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q
regulated chloride channel
function is enhanced by most, but not all anesthetics
anesthetics produce allosteric interactions; not a direct effect them
A

GABAA receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Glutamate-regulated cation channel

Anesthetics that do not interact with GABA receptors all inhibit these receptors

A

NMDA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Most anesthetics will increase _____ opening via allosteric effects to increase Cl- conductance

A

GABA a

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

Stages of Genreal anesthesia

A

Premedication
Induction
Maintaine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Keys for induction

A

want it to be non-frightening and non painful and we only induce with inhalational anesthetic in emergency, otherwise via IV

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

To maintain anesthesia with gaseious anesthetics keep in mind

A

they have short 1/2 lives and need to constantly be administered

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

All parenterally admin anestetics are

A

hydrophobic and given as single IV bolus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Single iv bolus results in a high concentration in ________within a single circulation time; results in_____ induction of anesthesia

A

brain and spinal cord

RAPID

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What happens as blood levels of anesthetics drop after induction

A

As blood levels drop, anesthetic redistributes back into the blood from the brain and winds up in other tissues where it is slowly released and metabolized

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

the half-life of the anesthetic in the body and the duration of action are

A

not the same

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

duration of action is _____ than half life thus multiple dosing is _____

A

shorter

complex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
typical barbituate anesthetic
sodium thiopental
26
Barbituate used to induce anesthesia; typical induction dose produces unconsciousness in 10 to 30 sec; duration of action of a single dose is about 10 min.
sodium thiopental
27
1/2 life of sodium thiopental
Has a long half life (12 hours) so can produce residual effects (hang-over) after anesthesia has worn off
28
When do we reduce the dose of sodium thiopental we give to patients?
Dose should be reduced if patient has been premedicated with other CNS depressants, including opiates, benzodiazepines and alpha2 agonists.
29
Sodium thiopental works by
activating GABAa receptors
30
Why dont we give intra-arterial injection of sodium thiopental
causes necrosis and inflammation
31
how can we deliver sodium thiopental to peds patients
rectally
32
CNS affects of sodium thiopental
Reduces cerebral oxygen utilization, and, as a consequence, reduces cerebral blood flow and intracranial pressure Has been tried as a protective agent for the treatment of cerebral ischemia
33
CV affects of sodium thiopental
Vasodialation---espeicially venodialation | **DONT use for pts with reduced pre-load or cardiomyopathy-- see severe drop in BP
34
Can we use barbiutates in pts with coronary artery disease?
yes because its not arythmogenic
35
Affect on respiration sodium thiopental has
respiratory depression--- often need to intubate pts bc they stop breathing
36
Propofol: onset and duration: uses:
Propofol(Diprivan®) 1. Onset and duration of anesthesia are the same as barbiturates 2. Is used to maintain and induce anesthesia
37
Is antiemetic, an advantage as many patients are nauseated following surgery
Propofol
38
Has a shorter half-life than thiopental; used when a rapid return to normal mental status is desired (out-patient surgery, for example)
Propofol
39
Mech of Propofol
GABAa
40
Half life of propofol in the body
3.5 hours with much less hangover than barbituates.. HUGE for usefullness in outpatient surgeries
41
Unique side effect of propofol
pain at injection side thus gven with lidocaine | also causes initial excitaiton upon induciton
42
pain at injection side thus gven with lidocaine | also causes initial excitaiton upon induciton
Propofol
43
3.5 hours with much less hangover than barbituates.. HUGE for usefullness in outpatient surgeries
Propofol
44
CNS side effects of Propofol
CNS: Reduces cerebral oxygen utilization, and, as a consequence, reduces cerebral blood flow and intracranial pressure
45
CV effects with Propofol
more sever reduction in BP then thiopental see vasodialtion and depression of myocardial contractility blunts baroreflexes
46
What's the danger in propofol blunting baroreflexes
see depression of myocardial contractility but then they're not opposed by vasoconstriciton and HR will increase
47
What type of patients are intolerant to propofol
those intolerant to decreased BP | --contraindicated in pts with hypotension
48
Respiratory effects of propofol
more depression then thiopental
49
Primarily used to induce anesthesia in patients at risk for hypotension
Etomidate
50
has high incidence of pain on injection and myoclonus
etomidate
51
CNS effects of etomidate
CNS: Reduces cerebral oxygen utilization, and, as a consequence, reduces cerebral blood flow and intracranial pressure
52
Etomidate has____ respiratory depression than thiopental
Less
53
Drawback of etomidate
Significantly more nausea and vomiting than thiopental
54
What is concerning about etomidate post-surgery
ncreased post-surgical mortality due to suppression of the adrenocortical stress response; primarily when the anesthetic has been given for a prolonged period of time. Therefore, only used to induce anesthesia in patients prone to hemodynamic problems
55
produces dissociative anethesia and profound analgesia
Ketamine
56
This anethetic produces dissociative anesthesia, doesn't affect respiration and is a bronchodilator
ketamine
57
Ketamine is charcterized by:
1) profound analgesia 2) unresponsiveness to commands, even though eyes can be open 3) amnesia 4) spontaneous respiration
58
Administration of ketamine
typically administered iv but can also be used via intramuscular, oral and rectal routes
59
Ketamine mech
NMDA receptor anatagonist
60
Advantages of Ketamine
Advantages: profound analgesia, very little respiratory depression, bronchodilator
61
Side effects of Ketamine
Produces nystagmus, salivation, lacrimation, spontaneous limb movements and increased muscle tone increased intracranial pressure
62
Produces nystagmus, salivation, lacrimation, spontaneous limb movements and increased muscle tone increased intracranial pressure
Ketamine
63
causes emergence delierium adn increased BP dt sympathomimetic affect
Ketamine
64
Ketamine is reserved for pts with
broncospasm that can't be indubated | good for children undergoing short, painful procedures
65
Short acting benszo that is a GABAa activator
Midazolam
66
used alone for conscious sedation, anxiolysis and amnesia for short procedures or as an inducing agent
MMidazolam
67
Mech of Midazolam
Short acting benszo that is a GABAa activator
68
good adjunt for local anestheticsm or pre-op to decrease anxiety
midazolam
69
Compared to thiopental, midazolam has ____ duration of action and _____ induction
longer duration | slower induction
70
Midazolam must be ______ to it's active metabolite
Metabolized by hydroxylation to an active metabolite
71
a. Has been associated with respiratory depression and respiratory arrest especially when used intravenously to produce conscious sedation
Midazolam
72
Pt population to be careful when administering Midazolam
Should be used with caution in patients with neuromuscular disease; Parkinson’s disease; bipolar disorder
73
Induction for patient surgery and causes hypotension and hang over
Thiopental
74
Used for induction/maintence especially outpatient and cuases hypotension and respiratory depression
Propofol
75
Used for induction in pts that have hypotention but causes nausea and adrenal suppression
Etomidate
76
Used for pts with broncospasm or in kids for short, painful procedures
Ketamine
77
Used for cons sedation and as an anti-anxiety but has slow induction with respiratory depression
Midazolam