Chapter 8 - Neurosurgery and Invasive Neuroradiology Flashcards

1
Q

What is the CBF in infants and children?

A

90 to 100 ml/100 g/min

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2
Q

What is the CBF in adults?

A

50 to 60 ml/100 g/min

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3
Q

The CBF varies directly with changes in PaCO2 between what ranges?

A

20 to 80 mmHg

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4
Q

The CBF changes aproximately ___% per each mmHg of change in PaCO2?

A

4% change in CBF

for

every mmHg change in PaCO2

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5
Q

Vasoconstriction in normal reactive cerebral vessels in areas that have lost autoregulation will reduce the blood flow?

A

F

Vasodilate

Termed: Intracerebral Steal

  • AVMs
  • Vascular tumors
  • Areas of infection or trauma
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6
Q

Crebrovascular autoregulation operates over a wide range of mean arterial pressures as low as ___ to ___ mmHg in the supine infant?

A

As low as

20 to 60 mmHg

in the supine infant

  • 50 to 150 mmHg in adults
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7
Q

T/F

Hyperventilation is a way to decrease cerebral blood volume and is generally reserved for acute in ICP

A

T

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8
Q

What is inverse intracranial steal?

A

Vasoconstriction

Increases blood flow into areas that lost autoregulations

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9
Q

What are the 3 fixed consituents of the intracranial contents?

A

Blood

Brain tissue

CSF

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10
Q

T/F

All inhalational agents decrease CBF and reduce the ICP because of their vasodilatory effects

A

F

All inhalationals increase CBF

May increase ICP

**Unless accompanied by mild hyperventilation

(PaCO2 ~ 30 to 35 mmHg)

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11
Q

What is the order that the volatile anesthetics follow from greatest to least and their effect on the CBF?

A

Des > Hal > Iso > Sevo

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12
Q

What are the three volatile agents that reduce CMRO2?

A

Halo, Iso, Sevo

  • Iso** and **Sevo may provide cerebral protection

against

Hypoxia & Ischemia

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13
Q

What is the ideal induction agent in neurosurgery?

Why?

A

Thiopental

Reduces ICP

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14
Q

T/F

Thiopental reduces ICP, therefore stimulation from laryngoscopy and intubation is not an issue.

A

F

Thiopental DOES NOT prevent

increase in BF and ICP

during laryngoscopy and intubation

Administer:

  • Lidocaine 1 to 1.5 mg/kg

and

  • Fentanyl 2 to 5 mcg/kg
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15
Q

What induction agent reduces CBF, CMRO2 and preserves autoregulation?

A

Propofol

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16
Q

T/F

Induction doses of Propofol 3 mg/kg may cause mild hypotension but may also MORE effectively blunt the CV response to laryngoscopy and intubation.

17
Q

Which opioid has been demonstrated to increase CSF pressure in children with crebral tumors?

A

Alfentanil

18
Q

Nondepolarizing muscle relaxants have no direct effect on CBF, except?

A

Atracurium

Vasodilation from histamine release

19
Q

What occurs with the administration of succinylcholine to children with cerebral trauma and other CNS diseases?

A

Hyperkalemia

20
Q

T/F

Calcium channel blockers impair autoregulation and may increase CBF and ICP

A

T

  • Sodium Nitroprusside
  • Nitroglycerine
  • Adenosine
  • Calcium Channel Blockers

All impair cerebral autoregulation and may increase CBF and ICP

21
Q

What med may decrease focal cerebral edema in response to surgical trauma of brain tissue?

A

Dexamethasone

0.15 mg/kg IV

MAX of 8 mg

22
Q

T/F

Ketamine increases neuronal function

A

T

Ketamine increases neuronal function

and

increases CBF

23
Q

T/F

Thippental Decreases neuronal function

A

T

Thipental decreases neuronal function

and

decreases CBF

24
Q

T/F

SSEP monitoring is attenuated by inhalational anesthetics

25
T/F Nitrous oxide Propofol Opioids & Muscle relaxants **have litlle effect on SSEPs?**
T
26
What has more sensitivity to the inhalational anesthetics, SSEPs or MEPs?
**MEPs** Motor Evoked Potentials
27
During MEPs, the inhalational agents are limited to what MAC value?
Limited to 0.5 MAC
28
What inhalational agent is avoided wjen MEPs is used?
Nitrous oxide
29
T/F During MEPs, muscle relaxants are completely avoided
30
T/F Propofol Alpha - 2 Agonist Benzos and opioids DO NOT significantly compromise MEPs.
T
31
A PaCO2 of what range is preferred during controlled ventilation?
PaCO2 of 30 to 35 mmHg