Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Pharmacology #1 > Module C-1 IV Anesthetics > Flashcards

Module C-1 IV Anesthetics Flashcards

1
Q

Differences in Propofol storage

A

Diprivan- EDTA (preservative)-no problems

Generic- metabisulfate- bronchospasm?

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

GABA

A

Primary inhibitory neurotransmitter in brain

Binds GABA receptors on ligand-gated ion channel- causing chloride to flow into the cell and hyper polarizing the postsynaptic cell membrane

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

Metabolism and clearance propofol

A

Clearance exceeds hepatic blood flow

Hepatic oxidative (CYP) metabolism is rapid

Extrahepatic elimination via lungs

Elimination halftime 0.5-1.5 (4-5 half-lives to eliminate)

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

Propofol induction

A

Adults 1.5-2.5 mg/kg

Pediatric higher doses per kg of body weight

Elderly 25-50% decrease in dose- decreased clearance and smaller central compartment

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

Propofol maintenance (TIVA)

A

Adults 100-300 mcg/kg/min

Significant antiemetic effect

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

Propofol dosing Conscious Sedation

Antiemetic/antipuritic dosing

A

Adult 25-100 mcg/kg/min. (This is ICU dosing lol)

10-15mg IV

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

Propofol CNS impact

A

Decreases CMRO2, CBF and ICP-maintains auto regulation

Minimal impact on evoked potentials

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

Propofol Cardiovascular response

A

Relaxation of vascular smooth muscle due to sympatholytic effect (not direct action on vasculature)

Negative inotropy

Exaggerated in hypovolemia, older adults, impaired left ventricle

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

Propofol lungs and kidneys

A

Apnea, decreased response to arterial hypoxemia

Little impact on liver/kidneys

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

Propofol. Allergies

A

Most people are allergic to egg whites

Lipid is egg yolk- if hx of anaphylaxis there is a theoretical risk

No documented rxns to soy-highly refined lipid emulsion with proteins removed

Current recommendation is that this is not a contraindication

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

Propofol infusion syndrome

A

Impaired fatty acid metabolism and mitochondria-rhabdo

Infusions greater than 24-48 hrs (high dose)

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

Etomidate- receptor and clinical use

Dosing

A

GABA receptor modulation (highest selectivity of all agents)
High lipid solubility and Vd like propofol

Cardiovascular instability- LV dysfunction or shock
Pt we want to avoid hypotension- impacts on cerebral pp/ ESRD

Induction- 0.2-0.4 mg/kg IV bolus

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

Etomidate downsides (four)

A

Myoclonus- common, pretreat with like any drug

Inhibits 11 B-hydroxylase (required for adrenal hormone synthesis)
-cortisol levels suppressed for 8-24 hrs

PONV

Contraindicated in AIP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Etomidate CNS and Cardiac effects

A

Decreases CBF, CMRO2, ICP

-small sympatholytic effect preserves BP
Unmasking effect- Pts with exaggerated sympathetic tone (severe hypovolemia) may see worsened hypotension

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

Acute intermittent porphyria

A

Alterations in heme biosynthesis resulting in accumulation of heme precursors in tissue

ALA-synthetase induction accelerates precursor synthesis-Etomidate induces this enzyme

Symptoms- abd pain, vomiting, seizures, AMS, HTN tachy

-Propofol and all inhaled anesthetics are safe

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

Ketamine- in general

A

Dissociative Anesthesia-catatonic state

Minimal cardiac/pulmonary effects

Airway reflexes preserved

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

Ketamine MOA

A

NMDA receptor Antagonist- antagonizes an excitatory pathway

Normally NMDA or glutamate displace Mg in ion pore making it permeable to Ca or Na

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

Ketamine- Cardiac/Pulmonary and analgesia

A

Preservation of CO (B1 agonism) and BP
-maintenance/increase of sympathetic tone in patients with normal catecholamine stores

Bronchodilation (B-2 agonism)

affects opioid receptors (mu and kappa)

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

Ketamine dosing

A

IV Induction 2-2.5 mg/kg (3-5 min for full effect)

IM 4-6mg/kg 5-15 min for onset of anesthesia

Oral- high first pass in Liver 10 mg/kg

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

Ketamine Elimination

A

Elimination half life is 2-3 hours- dependent on hepatic blood flow (high extraction) with an active metabolite

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

Ketamine Clinical uses

A

Shock/ LV dysfunction

Bronchospasm

Maintenance of spontaneous ventilation

Opioid sparing- multimodal

Analgesia in chronic pain 5-120 mcg/kg/min

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

Ketamine CNS

A

CBF, CMRO2, ICP increased- most likely safe if controlling paCO2 with ventilation

No impact on evoked potentials

Emergence delirium- co-administer benzos/prop. Less likely with a lose dose infusion

23
Q

Ketamine Eye sx

A

Increased IOP and nystagmus (increased muscle tone)

24
Q

Methohexital

A

Currently used in ECT due to lowering of the seizure threshold

25
Q

Barbituate MOA & and organ impact

A

GABA receptors modulation

Antagonism of glutamate at AMPA receptors (excitatory pathway)

CNS depression
Venodilation-decreased CO
Suppresses ventilation
Contraindicated in AIP

26
Q

Benzodiazepines MOA

A

Subset of GABAa receptors (alpha subunits)
Enhances GABA with ceiling effect
Not induction agent

27
Q

Benzo kinetics

A

This is how they are classified (elimination half lives)
Long onset- 10 minutes (stacking doses will lead to oversedation)

28
Q

Diazepam

A

Longest actin (t1/2>24hrs)
Large Vd and stays in peripheral tissues
Many active metabolites
Almost entirely hepatic metabolism
Linear relationship with age- as you age the half-life gets longer

29
Q

Lorazepam

A

Moderate acting (T 1/2= 6-24 hrs)
Less dependent on hepatic cytochrome enzymes than diazepam

30
Q

Midazolam

A

Short Acting (<6hrs)
More rapid metabolism via hepatic cytochrome enzymes

31
Q

Benzo clinical uses

A

Oral use in pediatrics-20-30min peak effect

Anterograde amnesia!! Don’t form NEW memories- not reliable at the lower doses
Anxiolysis
Pre-induction agent
Muscle spasms
restless leg- clonazepam

32
Q

Benzo reversal

A

Flumazenil- can precipitate seizures in Benzo dependent patients
Half life <1 hr and should be monitored for re-sedation
0.2mg, titrate slowly- don’t exceed 1mg

33
Q

Dexmedetomidine MOA

A

Alpha2 agonists in CNS- these receptors are GPCRs- when activated inhibit Ca channels and activate K channels- hyperpolarizes the cell and causes reduced NE release

34
Q

Dex Kinetics

A

Elimination half-life 2 hours

Context sensitive halftime- 25-120 min after 1 hour infusion and 87-120 min for >6hrs

35
Q

Dex clinical uses

A

Maintaining respiratory drive/easily arousable

No Amnesia!!

Concomitant with volatile anesthetics
decreases MAC and dose requirements in TIVA

Decreases emergence delirium

36
Q

Dex CNS

A

Mimics natural sleep- UNLIKE GABA agonists

OK in evoked potentials

Decrease in CBF, no change in CMRO2

Antishivering/blunted response to surgical stress

Analgesic effects

37
Q

Dex Cardiovascular

A

Hypotension due to vasodilation- pronounced in pts with high sympathetic tone (hypovolemia)

Bradycardia- dangerous in AV II or III blocks

Transient HTN in loading dose- due to direct efffects on peripheral alpha receptors

38
Q

Dex miscellaneous lol

A

Antisialagogue

Mild diuretic effect

39
Q

Pharmacokinetic similarities btw IV Anesthetics

A

Large Vd > 0.7
Highly protein bound (except ketamine)
Elimination half-life=half life

40
Q

Propofol MOA

A

GABA Agonist- B2 subunit

Directly activates receptor and potentiates GABA mediated responses

10-15 min for redistribution

41
Q

Propofol Generic vs Diprivan & Fospropofol

A

Diprivan- bronchodilation (EDTA)

Generic- Bronchospasm due to preservative metabisulfate- avoid in asthmatics

Fospropofol- not approved as a replacement
-PK is not as good as

42
Q

Etomidate Metabolism

A

Hydrolysis via hepatic microsomal enzymes- renal excretion- no active metabolite

43
Q

Adrenocorticoid Suppression Etomidate

A

11-B-hydroxylase inhibition prevents conversion of cholesterol to cortisol and aldosterone

Problematic in patients reliant on intrinsic stress response

44
Q

Barbituate metabolism and elimination

A

Hepatic

Long elimination half-life (hangover effect) and Long context sensitive halftime due to zero order kinetics at high doses

45
Q

What causes histamine release??

A

Thiopental which we don’t fucking use

Leads to bronchoconstriction and hypotension

46
Q

Subclasses of alpha receptors

A

Alpha 1- vasoconstriction drug target
-Post synaptic nerve fiber

Alpha 2- CNS and PNS
-Pre and Post synapse Sites
-Presynaptic activation inhibits NE release (negative feedback)

47
Q

Dex effect site location

A

Locus Coeruleus- Brain-highest density a2 receptors in the CNS
Activation reduces arousal and sympathetic outflow

Spinal cord- modulates nociceptive input- potentially reduced glutamate release

48
Q

Dex metabolism/elimination

A

Hepatic, CYP450

Sensitive to hepatic impairment

VARIABLE context sensitive halftime

49
Q

Dex dosing

A

0.5 mcg/kg over 15. Min (probably longer)

0.3-0.7 mcg/kg/hr

50
Q

Scopolamine

A

Anti cholinergic
Lipid soluble (BBB)
Acts on Reticular Activating System-sedation and some amnesia

Little hemodynamic impact
0.2mg?

51
Q

Dex loading and infusion

A

1mcg/kg over 10-15 min

0.4-0.7 mcg/kg/hr

52
Q

Which IV anesthetics have active metabolite

A

Ketamine-norketamine 1/3 potency

Midazolam- 1-hydroxymidazolam 0.5x potency

53
Q

Drugs to avoid in acute intermittent porphyria

A

Barbiturates
Etomidate
Ketamine

Pharmacology #1 (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions