Nurs614 Exam 2 Induction Of Anesthesia: Increased Icp

Front 1

3 factors that determine intracranial pressure

Back 1

Cerebral blood flow
Cerebrospinal fluid
Brain matter

Front 2

What is Intracranial Hypertension (increased ICP)?

Back 2

Defined as sustained ICP above 15 mmHg (increases can be in tissue or fluid - blood or CSF)

Front 3

Signs and Symptoms of Increased ICP

Back 3

Headache
Nausea and vomiting
Papilledema (optic disc)
Focal neurologic deficits
Altered consciousness

Front 4

How does ICP increases above 30 mmHg affect cerebral blood?

Back 4

Flow progressively decreases

Front 5

What does decrease blood flow lead to?

Back 5

Leads to ischemia of tissues;
Ischemia leads to brain edema;
Brain edema leads toincreased ICP.
This is a circular pattern that will lead to herniation of brain stem.

Front 6

As part of our neurological assessment, we can do ventriculostomy monitoring. What do we monitor for using this device?

Back 6

Amount and characteristics of drainage of CSF.
A catheter sits in the ventricle - can directly measure ICP and/or drain CSF

Front 7

As part of our neurological assessment, we can do use the camino as a monitoring device. What do we monitor for using this device?

Back 7

It is a direct measurement of ICP

Front 8

Anticonvulsant therapy like dilantin can be used to tx increased ICP. What are some considerations regarding the use of Dilantin relative to anesthesia

Back 8

Dilantin is incompatible with many other drugs - it will cause crystalization if it mixes with may drugs in the tubing;
It induces CYP450 --> decreased T1/2 of many drugs.

Front 9

Identify specific medications for increased intracranial pressure

Back 9

Diuretic therapy (loop like lasix, mannitol);
Anticonvulsant therapy;
Corticosteroids

Front 10

As part of the pre-op evaluation the we may assess for a midline shift via CT or MRI.What should we look for?

Back 10

Look for signs of brain edema;
Affected ventricle may shift –edematous brain tissue pushes in ventricle on the affected side;
Look for midline shift greater than 0.5 cm;
Identify ventricular size.

Front 11

If signs of increased ICP are present, we want to avoid pre-medication. What is the rationale?

Back 11

We do not want to drop RR as this will -->increase CO2--> cerebral vasodilation --> increased BF --> increased ICP

Front 12

With regards to ICP during induction, what is our goal?

Back 12

The goal of induction to keep the ICP the same, or lower if possible (to maintain appropriate CCP).

Front 13

CPP =

Back 13

MAP –ICP or
MAP –RAP if RAP is higher than ICP.

Front 14

How does internal jugar vein IV access affect ICP

Back 14

Can cause decrease of venous drainage from cerebral area

Front 15

Appropriate hemodynamic monitoring include arterial line. Should this be placed before or after induction?

Back 15

Arterial line should be placed prior to induction to closely monitor BP through out induction and intubation.

Front 16

To avoid SNS stimulation from pain during the aline placement, what is one thing we do?

Back 16

Use topical anesthesia during IV placement to avoid HTN related to pain

Front 17

What are the best induction agents to in a pt with increased ICP?

Back 17

Propofol and Thiopental. Start out at the low end of the dose range to avoid decreasing the CPP.

Front 18

Why do we not want to use Ketamine for induction in the pt with increased ICP?

Back 18

Ketamine will increase ICP b/c it increases BP thu prevention of NE reuptake

Front 19

Under what condition can we use Etomidate for induction in the pt with increased ICP?

Back 19

Etomidate is appropriate if used with sufficient amount of fentanyl (5 mcg/kg)

Front 20

Why are Thiopental and propofol the most appropriate induction agent to use?

Back 20

They result in decrease in CMRO2
(neuronal activity is decreased);
They provide quick, deep induction of anesthesia.

Front 21

After a pt is intubated, what are some of the ways the anesthetic provider can reduce ICP?

Back 21

Hyperventilate (decreased CO2 --> cerebral vasoconstriction --> decreased ICP

Front 22

What can you do after induction & prior to intubation to decrease ICP?

Back 22

Turn on a small amount of inhalation agent to deepen anesthesia & increase cerebral vasodilation

Front 23

We can use adjunct agents to provide additional blunting of airway reflexes for intubation. What are the doasage guidelines for fentanyl & lidocaine & what else do these agents do?

Back 23

Fentanyl 5-10 mcg/kg
Lidocaine 0.5-1.0 mg/kg.
They avoid if risk of seizure.

Front 24

Use of NDMR during induction of a pt with elevated ICP - what if any special restrictions are there?

Back 24

Any NDMR can be used according to patient's history.
Ensure appropriate time is allowed for MR prior to intubation, coughing will sharply increase ICP

Front 25

Use of succinycholine during induction of a pt with elevated ICP - what if any special restrictions are there?

Back 25

Avoid succinylcholine, unless a RSI needs to be done.
Succinylcholine causes small, transient increases in ICP.

Front 26

How do we ensure that airway reflexes are blunted during intubation?

Back 26

Deep level of anesthesia;
Appropriate muscle blockade;
Attenuation of airway reflexes (avoid coughing).

Front 27

For the pt with elevated ICP in the OR - what are positioning considerations? in terms of the pt's airway

Back 27

The bed will be rotated 90-180 degrees which could lead to the CRNA losing control of airway control
Ensure proper securing of airway and all airway connections prior to movement of bed

Front 28

How does positiong of the pt affect ICPs

Back 28

Pt must be positioned appropriately (HOB raised) to promote venous drainage of blood and CSF.
Pt's head needs to be in a neutral position to avoid impedence of the jugular veins.