Brainscape's Knowledge GenomeTM

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


See full index

Anesthesia Pharm I > ketamine > Flashcards

ketamine Flashcards

1
Q

what is the classification of ketamine?

A
  • dissociative
  • non-barbiturate IV anesthetic
  • disconnects brain from body; hallucinations
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

who can ketamine not be given to r/t job?

A

public transport personnel (pilots, bus drivers, etc.) d/t possible reoccurrence of symptoms, may be barred from job

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

what is the MOA of ketamine?

A
  • binds non-competitively to N-methyl-D-aspartate (NMDA) receptors
  • exert some effect on opioid receptors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is the onset of ketamine?

A
  • rapid, similar to thiopental

- within 1 min (30-60 sec) of IV injection, less than 5 min (2-4 min) IM

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

what is the duration of ketamine?

A
  • short, similar to thiopental

- larger doses take longer to wear off

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

how does ketamine cross the BBB?

A
  • rapid transfer across, greater than thiopental (4-5x faster)
  • reason it is such a quick dissociative
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what patients are more at risk for side effects of ketamine?

A
  • < 15 y/o (kids already have nightmares)
  • female (tend to have more vivid dreams)
  • doses > 2 mg/kg
  • history of frequent dreams/nightmares
  • don’t give to PTSD
  • don’t give to pts. with mental disorders with hallucinations (schizophrenia)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what drugs help reduce side effects of ketamine?

A

benzodiazepines reduce emergence delirium and increase seizure threshold

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

what is observed with ketamine effects?

A
  • open eyes (glazed over)
  • behavior like catatonic state (seem really high)
  • nystagmus (eye twitching)
  • may move with no regard to surgical stimulation
  • amnesia
  • pain free
  • 1.4 in 100,000 have bradycardia related death (glycopyrrolate and versed lessens)
  • oculocardiac reflex is enhanced (certain nerves cause vagal decrease in HR, so pre treatment helps)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

describe emergence delirium with ketamine

A
  • 5-30% incidence
  • visual, auditory, proprioceptive and confusing illusions/hallucinations
  • dreams can occur up to 24 hrs after administration
  • central misinterpretation of visual and verbal stimuli
  • pt. may be combative
  • pad bed, surrounding
  • recover in quiet environment; not regular PACU
  • abuse potential
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what are anticholinergic effects of ketamine at muscarinic receptors?

A
  • delirium
  • bronchodilation
  • sympathomimetic action
  • give glycopyrrolate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is action of ketamine terminated and how is it eliminated?

A
  • redistributed form the brain to tissues that are highly perfused
  • high hepatic clearance that prolongs elimination 1/2 life as much as 2-3 hrs (less than 4% excreted renally)
  • chronic administration stimulates CP450
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

how is ketamine metabolized?

A
  • hepatic microsomal enzymes
  • CP450
  • active metabolite: Norketamine
  • liver disease not a good candidate for ketamine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what pts. may require an increased dose of ketamine?

A

pts. with induced CP450
- alcoholics
- smokers
- drug abusers

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

describe Norketamine

A
  • active metabolite of ketamine
  • onlyu 1/5 to 1/3 as potent
  • provides analgesia
  • contributes to prolonged analgesic effect of ketamine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what are clinical uses of ketamine for analgesia?

A
  • unique drug that provides wonderful analgesia at subanesthetic doses
  • provides prompt induction of anesthesia at higher doses
  • hip fracture or replacement and need to do a spinal: hurts to sit up; 30-40mg ketamine allows to sit up to place spinal
  • give antisialogogue like glycopyrrolate since atropine and scopolamine may cause emergence delirium also
17
Q

describe ketamine use for analgesia

A
  • intense analgesia can be accomplished with subanesthetic doses
  • works in the thalamic and limbic systems to inhibit interpretation of painful stimuli
  • used in conjunction with opioids as an adjuvant
18
Q

what is the analgesic dose of ketamine?

A

0.2-0.5 mg/kg

19
Q

when should ketamine be used in OB?

A
  • emergent use only! (there is no time for an epidural, spinal, or other inductions and need to get baby out quick!)
  • not good use in OB but better than thiopental
  • neurobehavioral scores of infants born by vaginal delivery are lower with ketamine than those born with epidural anesthesia (crosses placental barrier)
20
Q

what are neuraxial effects of ketamine?

A
  • limited efficacy
  • extradural dosages may be as weak as 10,000 fold weaker than morphine
  • has additive or synergistic effect when given with opioids neuraxially (can give less opioid)
21
Q

what are induction doses of ketamine?

A

IV: 1-4.5 mg/kg (avg. 2-3 mg/kg)
IM: 3-5 mg/kg OR 6-8 mg/kg
*0.25-1.0 mg produces minimal to mild effects

22
Q

what should be considered with dosing and onset of ketamine in elderly?

A
  • require lower induction mg d/t smaller central distribution volume
  • allow for circulation time (onset may be slower)
23
Q

what dose is typically used for maintenance after induction with ketamine?

A

half the initial dose usually every 10-20 min

24
Q

when is ketamine especially good to use?

A
  • induction of severely hypovolemic pts.

* CV stimulation (increased BP, HR, CO)

25
Q

what are CV effects of ketamine?

A
  • stimulating effects
  • maintains BP, HR, and CO d/t central stimulation of SNS and inhibition of nor-epi reuptake (*not good if already stimulated: tachycardia, HTN)
  • generally considered a myocardial depressant mostly seen with pts. with sympathetic blockade or have exhausted catecholamine stored
  • regional anesthesia
  • spinal cord transection
  • pts. in shock
  • drug abuse crisis
  • no histamine release
  • inhibits platelet aggregation
26
Q

what are clinical uses of ketamine apart from analgesia?

A
  • induction of children with management issues
  • mentally retarded/challenged pts.
  • burns and dressing changes (pain)
  • no prolonged pain effect, give something after!
  • beneficial bronchodilation makes useful in asthmatics (not 1st line)
  • hx of asthma ok, don’t use if active wheezing or bronchospasm
  • induction of pts. with history or family history of malignant hyperthermia (does not stimulate)
  • antidepressant (acts as chemical ECT)
  • restless leg syndrome (blunts inflammatory mediators that impair spinal cord blood flow)
27
Q

what are CNS effects of ketamine?

A
  • emergence delirium
  • increased ICP: potent cerebral vasodilator
  • less increase in ventilated pts., can be given to ventilated pt. with mildly elevated ICP (sedated so not as stimulating)
  • EEGs show that ketamine possesses anticonvulsant properties (but it is a direct CNS stimulant)
28
Q

what are respiratory effects of ketamine?

A
  • maintains CO2 drive for respirations
  • upper airway tone is maintained
  • good choice for full neck, big guys
29
Q

what are renal and hepatic effects of ketamine?

A

lab tests show it does not significantly alter renal or hepatic function

30
Q

what are drug interactions with ketamine?

A
  • hemodynamic depression with inhaled anesthetics
  • midazolam and diazepam can prevent cardiac stimulating effects and hallucinations
  • can enhance non-depolarizer actions (good with long surgeries)
  • avoid use with/or near aminophylline drugs, this can cause seizures

Anesthesia Pharm I (28 decks)

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