Pharm ketamine

Question 1

ketamine causes a dissociation between what to structures in brain

Answer 1

thalamocortical (sensory) and limbic system (association)

Question 2

What type state and gaze does a patient display with ketamine

Answer 2

cataleptic state with eyes open and slow nystagmic gaze (noncommunicative)

Question 3

Can patient move with ketamine?

Answer 3

varying degrees of hypertonicity or purposeful movement independent of surgical stimulation (myoclonic type movements)

Question 4

Is amnesia complete with ketamine?

Answer 4

no, give a benzo

Question 5

Emergence delirium

Answer 5

benzo to help prevent,
no data of risk for specific population, but use cautiously in those prone to delirium ex elderly, psych disorders,
30% rate

Question 6

Ketamine analgesia?

Answer 6

Yes, can help reduce opiate req

Question 7

Chemical structure of ketamine?

Answer 7

phencyclidine,
2–2-cyclo-hexanone,
partially water soluble,
RACEMIC mixture,

Question 8

S-enantiomer

Answer 8

more potent and less side effects, very expensive (Ketanest)

Question 9

MOA Ketamine

Answer 9

Binds noncompetitively to the phencyclidine recognition site on NMDA receptors. (blocks glutamate neurotransmitter)(Stops Na influx preventing depolarization)
Exerts weak action GABAA receptor,
Other receptors: opioid, monoaminergic, muscarinic, no, seratonin, Na channels

Question 10

Why does ketamine cause analgesia?

Answer 10

inhibits nitric oxide synthase

Question 11

How does ketamine stimulate sympathetic nervous system?

Answer 11

Inhibits reuptake of catecholamines

Induces catecholamine release-beta 2 agonism-respiratory relaxation

Question 12

pharmocokinetics ketamine

Answer 12

not significantly bound to plasma proteins,
extremely lipid soluble and crosses bbb,
leaves blood rapidly to be distributed to tissues,
3 compartment model of distribution,
recovery of single bolus dose is primarily redistribution,
metabolism through liver

Question 13

Metabolism of ketamine

Answer 13

hepatic microsomal enzymes,
Demethylation of ketamine to norketamine(1/3-1/5 potency),
norketamine may contribute to prolonged effects of ketamine with repeated doses,
Norketamine is hydroxylated and then conjugated into water soluble inactive glucuronide metabolites excreted through kidneys.

Question 14

What med can prolong effect of ketamine

Answer 14

benzos

Question 15

Aminister slowly reduces resp and cv s/e

Answer 15

over 60 sec

Question 16

CNS effects ketamine

Answer 16

Cerebral vasodilator (increase CBF and CMRO2)
Not recommended in pt with intracranial pathology,
considered anticonvulsant,
may cause myoclonic movement on injection

Question 17

CV effects ketamine

Answer 17

direct myocardial depressant,
depressant effects usually masked by stimulation of SNS,
May be significant in critically ill patients with limited SNS reserve,
Significant, transient increases in systemic BP, HR, CO,
Associated with increased cardiac work and increased cardiac metabolic requirement of O2

Question 18

Respiratory effects ketamine

Answer 18

No significant resp depression,
When alone, CO2 response preserved,
Transient hypoventilation,
Short periods of apnea with rapid administration,
RELAXES bronchial smooth muschle, may be helpful with reactive airways or bronchoconstriction,
Increased SALIVATION (use glycol or atropine)

Question 19

Overall for quiz

Answer 19

ketamine can be opiate sparing, less resp effect, potential delirium but offset by benzos but effects potentiate resp depression