Ncs Practice Update

Front 1

Treatment options for anxiety

Back 1

benzos, barbiturates, propofol

Front 2

agents that provide both anxiolysis and analgesia

Back 2

alpha 2 agonists, ketamine, low-dose opioids (morphine)

Front 3

medications with deleriogenic potential

Back 3

benzos, opioids, anticholinergics

Front 4

strategies to prevent delirium

Back 4

removing deleriogenic agents, establishing consistent sleep-wake cycles, appropriate pain management, removal of catheters and restraints, early mob and exercise, haldol and antipsychotics

Front 5

pharmacologic choices for sedation

Back 5

opioids, benzos, barbiturates, propofol, neuroleptics, alpha 2 agonists, ketamine; in icu, most commonly used is morphine, fentanyl, remifentanil

Front 6

MOA of opioids

Back 6

interacts with mu, delta and kappa opioid receptors

Front 7

opioids and ICP / CBF?

Back 7

no direct effect but hypercarbia from depressed respiratory drive may lead to cerebral vasodilation

Front 8

these analgesics may cause seizures

Back 8

normeperidine (active metabolite of meperidine) associated with excitatory syndrome that includes seizures

Front 9

how does morphine and fentanyl affect blood pressure?

Back 9

morphine may induce hypotension even at low doses due to histamine release; fentanyl tend to have little effect on BP at sedative doses

Front 10

how to avoid "overshoot" phenomenon in opiates

Back 10

overshoot phenomenon is catecholamine surge following reversal of opiates; dilute 0.4mg of naloxone in 10ml saline (40 ug/mL) and administer 40-80ug titrating to desired level of arousal

Front 11

metabolism of morphine

Back 11

liver

Front 12

clearance of morphine

Back 12

glucuronidation to two metabolites which are renally excreted

Front 13

duration of action of morphine

Back 13

4 hours

Front 14

peak effect of morphine / fentanyl

Back 14

morphine is 10-15 minutes; fentanyl is more lipophilic, peak effect in ~5 minutes

Front 15

duration of action of fentanyl

Back 15

30-60 minutes but accumulates in adipose tissue and skeletal muscle with repeated doses accounting for longer elimination half life of 3-8 hours

Front 16

metabolism of fentanyl

Back 16

cytochrome P450 sysntem to norfentanyl and other inactive metabolites that are renally excreted

Front 17

potency of fentanyl and remifentanyl cf morphine

Back 17

100x more potent than morphine

Front 18

remifentanil duration of action

Back 18

onset 1-2 minutes, short duration of action 3-10 minutes; rapidly metabolized, easy to titrate and unlikely to accumulate even with prolonged infusions

Front 19

disadvantage of remifentanil

Back 19

ideal pharmacokinetics to provide a true "on-off" agent but cost relative to morphine is higher; large doses may lead to apnea

Front 20

most potent synthetic opioid

Back 20

sufentanil

Front 21

MOA benzos

Back 21

potentiates GABA

Front 22

effects of benzodiazepines

Back 22

sedation, anxiolysis, ms relaxation, anterograde amnesia, analgesia (with diazepam), anticonvulsant activity (not all benzos)

Front 23

how do benzos affect hemodynamics?

Back 23

like opioids benzos typically provide therapeutic effects without changes to HR, BP and RR unless higher doses are used; high IV doses of diazepam may cause hypotension and increased HR

Front 24

side effects of benzos

Back 24

oversedation most common; precipitation of delirium, apnea when used in combi with opioids

Front 25

precautions to take with ativan

Back 25

continuous infusions, has propylene glycol diluent which can lead to toxicity when infused at high doses >/= 1mg/kg/day

Front 26

clue to lorazepam toxicity

Back 26

osmol gap, AGMA and ARF, in patient on lorazepam drip

Front 27

is midazolam diluted in propylene glycol?

Back 27

midazolam while highly lipophilic is an aqueous preparation as the HCl salt and is not diluted in propylene glycol

Front 28

reverse benzos

Back 28

flumazenil

Front 29

caution with flumazenil

Back 29

may precipitate ICP rise, systemic HTN, lowering of seizure threshold (esp TBI, longstanding benzos, neurosurg patients)

Front 30

inducers of P450

Back 30

rifampin, carbamazepine, phenytoin, phenobarbital

Front 31

inhibtors of P450

Back 31

macrolides, azole antifungals, protease inhibitors

Front 32

which antiseizure meds affected by P450 drugs

Back 32

diazepam and midazolam, (ketamine also)

Front 33

2 agents in ICU used for sedation, anxiolysis, analgesia

Back 33

clonidine, dexmedetomidine

Front 34

MOA of dexmedetomidine

Back 34

selective alpha 2 adrenergic receptor agonist with 10x affinity cf clonidine - presynaptic inhibition of descending noradrenergic activation of spinal neurons and activation of postsynaptic a2 adrenergic receptors - decreased sympathetic outflow from locus ceruleus - decrease in tonic activity in spinal motor neurons and spinothalamic pain pathways

Front 35

benefits of dexmedetomidine

Back 35

lowers shivering threshold, provides sedation without loss of attention and cognition

Front 36

side effects of dexmedetomidine

Back 36

bradycardia, hypotension; both dexmedetomidine and clonidine no significant effect on ICP but decreases cerebral perfusion pressure due to reduction in systemic arterial pressure

Front 37

elimination half life of dexmedetomidine

Back 37

2 hours; may increase up to 7.5 hours in patients with hepatic insufficiency (metabolized by liver, excreted by kidney)

Front 38

nonbarb sedative/analgesic structurally related to phencyclidine

Back 38

ketamine

Front 39

effects of ketamine

Back 39

causes functional and electrophysiological dissocation between thalamo-neocortical and limbic systems which produces an effect of "sensory isolation" - analgesic, sedative, amnestic

Front 40

MOA ketamine

Back 40

noncompetitive antagonist of NMDA receptor, also interacts with opiate receptors at the central and spinal sites

Front 41

potential advantages of ketamine

Back 41

maintains hemodynamic stability due to ability to induce catecholamine release; lack of impairment of laryngeal and pharyngeal reflexes or respiratory depressant effects, potential anticonvulsant effects

Front 42

patient on ketamine exhibits vivid nightmaters / psychomimetic or emergence phenomenon, treatment?

Back 42

benzodiazepines

Front 43

onset/offset/half life of ketamine

Back 43

on in <1minute, off in 5-10 minutes; half life 2-3 hours

Front 44

drug class of choice in patients with delirium

Back 44

neuroleptics

Front 45

MOA of neuroleptics

Back 45

blocks cerebral and peripheral (but not spinal) receptors (adrenergic, cholinergic, dopamine, serotonin and histamine)

Front 46

concern for phenothiazines

Back 46

lowers seizure threshold

Front 47

potential side effects of neuroleptics

Back 47

anticholinergic effects, increase prolactin secretion, NMS

Front 48

half life of haldol

Back 48

10-36 hours

Front 49

initial dose of haldol

Back 49

0.5-5mg

Front 50

atypical agents used for delirium

Back 50

olanzapine, quetiapine, risperdone

Front 51

time for peak levels for atypicals

Back 51

6h for olanzapine, 1.5h for quetiapine, 1 h for risperidone

Front 52

initial dose of quetiapine

Back 52

25-50mg BID titrated up to 200mg BID

Front 53

duration of treatment of delirium

Back 53

7-14 days

Front 54

hemodynamic effects of propofol

Back 54

hypotension due to vasodilation and negative inotropic effect; dose dependent respiratory depression

Front 55

clues to propofol related infusion syndrome

Back 55

metabolic acidosis, hyperkalemia, rhabdomyolysis, hypoxia, progressive myocardial failure

Front 56

how to prevent propofol infusion syndrome

Back 56

routine monitoring of electrolytes, lactic acid, creatinine kinase and/or triglycerides in patients receiving higher doses >80ug/kg/min for >48 hours