IV sedatives-hypnotics Flashcards Preview

CRNA - drugs > IV sedatives-hypnotics > Flashcards

Flashcards in IV sedatives-hypnotics Deck (38)
Loading flashcards...
1
Q

Advantage of propofol

A

More rapid return of consciousness with minimal residual effects compared to other induction agents

2
Q

Propofol MOA

A

Increases GABA affinity for GABAa receptor - prolonged channel opening, increased Cl- influx

3
Q

Effect of increased Cl- influx

A

Neuronal cell hyperpolarization - inhibition of the cell

4
Q

Propofol metabolism

A

P450 - water soluble metabolites excreted via kidneys. <0.3% excreted unchanged in urine

5
Q

Propofol induction dose:
MAC dose:
TIVA dose:

A

I: 1.5-2.5 mg/kg
MAC: 25-100 mcg/kg/min
TIVA: 100-300 mcg/kg/min

6
Q

Propofol PONV dose:

A

Subhypnotic: 10-15 mg IV

7
Q

Propofol CNS effects:

A

Decreased - CMRO2, CBF, ICP

DOES NOT EFFECT - cerebral autoregulation

8
Q

Propofol cardiovascular effects:

A

Decreased - SVR, inotropy
DOES NOT EFFECT - HR
Decreased SVR may be augmented in hypovolemic, elderly, compromised LV function

9
Q

Propofol SNS effect:

A

Suppression of sympathetic nervous system activity

10
Q

Propofol effects respiratory:

A

Dose-dependent decrease ventilation

11
Q

Propofol effects intraocular pressure:

A

Decreased immediately after induction of anesthesia

12
Q

Etomidate MOA:

A

Increases GABA affinity for GABAa receptor - prolonged channel opening, increased Cl- influx

13
Q

Etomidate metabolism:

A

Hepatic microsomal enzymes and plasma esterases

14
Q

Etomidate induction dose:

A

0.2-0.4 mg/kg IV

15
Q

Etomidate cardiovascular effects:

A

Minimal changes in - HR, SV, CO

Decreases - up to 15% decrease in MAP d/t decrease in SVR

16
Q

5 Benzodiazepine effects:

A

Anxiolysis, sedation/hypnosis, anticonvulsant, anterograde amnesia, SK muscle relaxation

17
Q

Benzodiazepine MOA:

A

Increased GABA affinity for GABAa receptor - increased frequency of channel opening, increased Cl- influx

18
Q

Benzodiazepine amnesic effect?

A

Amnestic effect is greater than sedative effect - patients may be awake, but remain amnestic for events and conversations

19
Q

Midazolam Vd elderly and obese:

A

Increased Vd resulting from enhanced distribution into peripheral adipose tissue

20
Q

Midazolam metabolism:

A

Rapidly metabolized by hepatic and small intestine P450 (CYP3A4) - hydroxymidazolam (1/2 potency) is rapidly conjugated and renally excreted

21
Q

Drugs that decrease midazolam metabolism?

A

cimetidine, erythromycin, calcium channel blockers, antifungal drugs - inhibit P450

22
Q

Midazolam CNS effects:

A

Decreases CMRO2, CBF. Autoregulation is preserved.

23
Q

Solo midazolam induction:

A

Increased ICP associated with laryngoscopy is not blunted

24
Q

Midazolam respiratory effects:

A

Dose-dependent decrease in ventilation by decreasing hypoxic drive

25
Q

Midazolam cardiovascular effects:

A

Decrease in BP, SVR. Increase in HR.

26
Q

Midazolam doses:

A

Induction: 0.1-0.2 mg/kg
IV sedation: 1-2.5 mg
Onset 30-60 sec, Peak 5.5 minutes, Duration 15-80 min

27
Q

Flumazenil MOA:

A

Benzodiazepine antagonist at GABA receptor sites, however lacks agonist activity

28
Q

Flumazenil dose:

A

0.2 mg, subsequent doses of 0.1 mg q1min

29
Q

Ketamine MOA:

A

Produces dissociative anesthesia by interrupting signals between the thalamus and cerebral cortex. Patient is amnesic and analgesic

30
Q

Limit as sole anesthetic:

A

High frequency of emergence delirium

31
Q

Ketamine specific targets:

A

NMDA: inhibits activation by glutamate and prevents presynaptic release of glutamate
GABAa: only weak actions compared to propofol

32
Q

Ketamine dose:

A

Intubating: 1-2 mg/kg IV
Analgesia: 0.2-0.5 mg/kg IV

33
Q

Ketamine CNS effects:

A

Mildly increased ICP, can be maintained with normal ventilation

34
Q

Ketamine cardiovascular effects:

A

SNS stimulation - increases systemic and arterial blood pressure, HR, CO, myocardial O2 demand

35
Q

Ketamine respiratory effects:

A

DOES NOT decrease ventilation. Bronchodilates. Increased salivary and pulmonary secretions - glyco

36
Q

Ketamine cardioprotective effects:

A

R(-) isomer blocks cardiac preconditioning

37
Q

Dexmedetomidine MOA:

A

Alpha-2 agonist - sedation produced by a reduction in SNS tone

38
Q

Dexmedetomidine ventilation effects:

A

Dose not reduce ventilation