IV induction agents

Question 1

Dose of propofol

Answer 1

2 mg/kg

150-200 mg IV

Question 2

Propofol infusion rate

Answer 2

100-300mcg/kg/min

Question 3

Etomidate disadvantages

Answer 3

Adrenal suppression
Myoclonus
Postop nausea and vomiting

Question 4

Etomidate dose

Answer 4

0.2 mg/kg

20 standard

Question 5

Ketamine advantages

Answer 5

Can be used IM
Analgesic
Bronchodilator

Question 6

Ketamine disadvantages

Answer 6

Avoid in patients with increased ICP
Emergence delirium and hallucinations
Increases HR and BP

Question 7

Ketamine dose

Answer 7

2 mg/kg IV

4 mg/kg IM

Question 8

Thiopental half life

Barb coma

Answer 8

10 hrs

Suppress seizures in status, neuroprotection in focal ischemia

Question 8

Which agent is used in ECT?

Which agent is used in seizure surgery?

Answer 8

Methohexital

Etomidate

Both activate epileptic foci

Question 8

How does thiopental reduce BP?

3 ways

Answer 8

Dilation of capacitance vessels

Blunted baroreceptor response (not as much as prop)

Negative inotropy

Question 8

Lower dose of thiopental in the elderly, why?

Answer 8

Pharmacokinetically, elderly patients have a smaller central compartment and clear drugs much more slowly

Question 9

Which types of enzymes are induced by barbiturates?

Answer 9

CYP450

ALA synthetase (acute intermittent porphyria): increases porphyrin formation

Question 10

Chronic administration of barbiturates has what effect on dosage of BZDs?

Opioid prodrug? (Codeine, -codones , tramadol)

Anticoagulants?phenytoin?

Their own metabolism?

Answer 10

Chronic barb exposure increases the expression of CYP450 enzymes, thus requiring a higher dose of BZDs because they are broken down more quickly

Pts will require LESS codeine and other opioid pro drugs because the active form will become more available

OACs and phenytoin will get broken down more

They also enhance their own metabolism causing tolerance

Question 11

Propofol effects on the CNS

Answer 11

Decreases CBS, CMR 02, and I CP, may greatly decrease cerebral perfusion pressure as CPP = MAP - ICP, Also decreases IOP

Burst suppression flattened EEG

Not desirable with ECT

Question 12

Cardiovascular effects of propofol

Answer 12

Most pronounced decrease in BP of induction agents
Arterial and venous vasodilation next line marked inhibition of baro receptor response to hypotension

Negative Inotropy

Question 13

Propofol infusion syndrome

Population
Manifestation
Etiology

Answer 13

Critically ill children and adults receiving high dose infusions

Unexpected tachycardia metabolic acidosis heart failure and rhabdomyolysis

May be related to high lipid burden and mitochondrial failure

Question 14

Etomidate CNS effects

Answer 14

Decreases cerebral metabolic activity, CBF and ICP
May maintain CPP because there is little drop in MAP (MAP-ICP)
Causes excitatory space on eeg, may activate seizure foci
Maye clonus occurs in more than 50%

Question 15

Etomidate adrenal cortical suppression

Answer 15

Inhibits 11 B hydroxylase which converts cholesterol to cortisol

Lasts 4-8 hours

Question 16

How does ketamine work

Answer 16

It blocks the NMDA receptor which does allow for some analgesia
It causes dissociation between the thalamus and the cortex

Question 17

What are the cardiovascular effects of ketamine

Answer 17

Release of endogenous catecholamines
This increases HRBP and pulmonary artery pressure
Ketamine is a direct myocardial depressant, this affect is usually only seen in patients with autonomic nervous system dysfunction

Question 18

Ketamine’s affects on the pulmonary system

Effects on BIS

Answer 18

Bronchodilation, increased secretions

No significant change in BIS; The cortex is not been affected, only the communication between the thalamus and the cortex

Question 19

What is ketamine affect on cardiac work and myocardial oxygen consumption

Answer 19

Both are significantly increase due to catecholamine release

Question 20

What is the concern of giving atropine alongside of ketamine

Answer 20

This significantly increases the rate of emergence delirium

Question 21

In general, what is the effective anesthetic drugs on EEG

What are two exceptions?

Answer 21

Decreased frequency and increased amplitude, slowing toward Delta and theta wave from Alpha and beta

Opioids and ketamine

Question 22

Which two anesthetic to activate seizure foci

Answer 22

Methohexital and etomidate

Question 23

What do most anesthetic to do to SSEP

Which two are the exceptions?

Answer 23

Most increase the latency and decrease the amplitude of response to stimulus

etomidate and ketamine may increase amplitude

Question 24

Which anesthetics confound the use of the BIS monitor

Answer 24

Opioids ketamine and nitrous oxide

The usual affect of anesthetics on VIS monitor is decreased frequency and increased amplitude similar to EEG

Question 25

Does propofol or ketamine have a greater amount of analgesia

Answer 25

Ketamine

Question 26

Which anesthetic increases your pulmonary vascular resistance

Answer 26

Ketamine

Question 27

Does obesity affects the dosage of nondepolarizing NMB?

Answer 27

Not really, he does buy ideal body weight but you might add 20% to include the extra lean body mass

Question 28

Obesity and succinylcholine

Answer 28

Those must be increased because of the increased pseudocholinesterase activity