Neurophysiology pharmacology

Question 1

Alpha 1 agonists may cause

Answer 1

bolus: may transiently change CBF & cerebral SaO2
continuous: little effect on CBF & cerebral SaO2
- maintenance of CPP with these vasopressors does not have an adverse effect on the brain

Question 2

Alpha 2 agonists may cause

Answer 2

decreased CBF (up to 25-30%)
results from reduced CMRO2 leading to reduced CBF
small doses= little effect on CBF
large doses+ phys stress= increased in CMRO2 & CBF  up to 20%*******

Question 3

Beta blockers have

Answer 3

little to no effect on CBF & CMRO2

Question 4

Ace inhibitors & ARBs have

Answer 4

little to no effect on CBF & CMRO2

autoregulation is maintained

Question 5

Do not give ________ prior to any intracranial procedure.

Answer 5

benzos
may prolong emergence… unable to do post op neuro exam
less reduction than barbiturates, propofol, or etomidate

Question 6

Barbiturates are associated with

Answer 6

the robin hood effect (reverse steal phenomenon)**

CBF redistributed from normal to ischemic areas in the brain

Question 7

Propofol leads to

Answer 7

dose-dependent reduction in CBF & CMR*
anticonvulsant
short elimination half-life**

Question 8

Etomidate can

Answer 8

activate seizure foci in patients with epilepsy*****
-decreases the CMR, CBF, & ICP
has been used to treat seizures although not the first choice

Question 9

Ketamine is the only intravenous anesthetic that

Answer 9

dilates cerebral vasculature & increases CBF****
can potentially increase ICP markedly if decreased intracranial compliance
CMR does not change

Question 10

Ketamine as a sole agent can

Answer 10

increase ICP
when co-administered with other anesthetics, increased in CBF & ICP is blunted or eliminated
may result in stormy emergence*

Question 11

NMDA antagonism in brain injury patient may be

Answer 11

protective against neuronal cell death**

functionally “dissociates” the thalamus from limbic cortex

Question 12

Opioids have

Answer 12

minimal effects on CBF, CMR & ICP

morphine & meperedine is traditionally avoided

Question 13

Most anesthetics have ___________

Answer 13

favorable effect on CNS*****

Question 14

In general, anesthetic drugs ______

Answer 14

suppress the CMR with EXCEPTION of ketamine & nitrous oxide

Question 15

_______ & ________ blunts increase CBF/ICP from ketamine & volatile agents

Answer 15

hyperventilation & PaCO2

Question 16

Effects on CNS are complicated by

Answer 16

other drugs, surgical stimulation, intracranial compliance, BP & PaCO2

Question 17

The delivery of energy substrates is dependent on

Answer 17

CBF

Question 18

Modest alterations in CBF can substantially influence

Answer 18

neuronal outcome in the setting of ischemia

Question 19

Control & manipulation of CBF are central to the management of

Answer 19

ICP

Question 20

CBF does not parallel CBV when

Answer 20

there is normal BP (MAP 70-150 mmHg): autoregulation intact

cerebral ischemia: CBV increases but CBF decreases

Question 21

MAP=

Answer 21

CBF, but cerebral vasoconstriction limits in CBV

Question 22

Initial increases in CBV do not increase ICP due to

Answer 22

compensatory adjustment

• venous blood shift to extracerebral vessels
• CSF shift to spinal compartment