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.

A

T

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

A

T

25
Q

T/F

Nitrous oxide

Propofol

Opioids

&

Muscle relaxants

have litlle effect on SSEPs?

A

T

26
Q

What has more sensitivity to the inhalational anesthetics, SSEPs or MEPs?

A

MEPs

Motor Evoked Potentials

27
Q

During MEPs, the inhalational agents are limited to what MAC value?

A

Limited to 0.5 MAC

28
Q

What inhalational agent is avoided wjen MEPs is used?

A

Nitrous oxide

29
Q

T/F

During MEPs, muscle relaxants are completely avoided

A
30
Q

T/F

Propofol

Alpha - 2 Agonist

Benzos and opioids DO NOT significantly compromise

MEPs.

A

T

31
Q

A PaCO2 of what range is preferred during controlled ventilation?

A

PaCO2 of 30 to 35 mmHg