Induction Of Anesthesia: Increased Icp

Front 1

What three factors determine intracranial pressure?

Back 1

cerebral blood flow
cerebral spinal fluid
brain matter

Front 2

How is intracranial hypertension defined? (what value?)

Back 2

ICP >15mmHg sustained
increase can be in tissue or fluid (blood or CSF)

Front 3

Name 5 s/s of Increased ICP

Back 3

H/A
N/V
papilledema
altered LOC
focal neurologic deficits

Front 4

Describe the circular pattern of intracranial hypertension

Back 4

ICP>30mmHg -> decreased cerebral blood flow -> cerebral ischemia -> brain edema -> further increase in ICP -> .....

Front 5

What is the end result of the circular pattern of increased ICP if untreated?

Back 5

Herniation of brain stem

Front 6

A pre-op neuro eval will include....?

Back 6

1)Assessment for neuro DEFICITS
2)Check for neurological MONITORS
3) Identify specific MEDICATIONS for increased ICP
4)assess for MIDLINE SHIFT on CT or MRI

Front 7

When assessing a ventriculostomy, what should be noted?

Back 7

LEVEL of drainage
AMOUNT of drainage
CHARACTERISTICS of drainage

Front 8

Is a Camino Monitor or Bolt a direct measure of ICP?

Back 8

Yes

Front 9

In assessing medications pre-op, what therapies should you be alert to?

Back 9

-Anticonvulsants
-Diuretics-osmotic (Mannitol) and loop (Lasix)
-Corticosteroids

Front 10

The patient is on dilantin. What is important to remember?

Back 10

Dilantin increases the metabolism of most drugs and has many interactions

Front 11

When assessing CT or MRI pre-op, what are you looking for?

Back 11

1)Midline shift > 0.5 cm (compression of one of the ventricles on one side vs. the opposite side)
2) ventricular size
3) signs of brain edema

Front 12

Should patients with increased ICP be premedicated? Explain why or why not.

Back 12

AVOID! Premedication can drop RR, causing increase in CO2 and increased cerebral blood flow, increasing ICP

Front 13

What is the overall goal during induction of patient with increased ICP?

Back 13

keep the ICP the same or lower oif possible

Front 14

Where do you want the BP of a patient with increased ICP?

Back 14

As close to normal as possible to provide appropriate cerebral perfusion pressure.
(MAP of 60 if not higher)

Front 15

How is CPP calculated?

Back 15

CPP=MAP-ICP or
CPP=MAP-CVP if ICP is not available

Front 16

Can central lines be placed in patients with increased ICP?

Back 16

Yes, but avoid IJ-can obstruct venous drainage from brain

Front 17

How should BP be monitored in pt with increased ICP?

Back 17

A -line is best to closely monitor thru induction and intubation

Front 18

What special consideration should be taken when placing a line in apatient with increased ICP?

Back 18

Use local to prevent pain related hypertension

Front 19

Which induction agent should be avoided in patients with increased ICP? Why?

Back 19

Ketamine-will increase ICP

Front 20

Is Etomidate an appropriate induction agent for use in patients with increased ICP?

Back 20

Yes if used with sufficient amounts of fentanyl
(5mcg/kg)

Front 21

What is the dose of fentanyl that should be given with Etomidate if used for induction?

Back 21

5mcg/kg

Front 22

what are the best choices for induction of a pt with increased ICP? Why?

Back 22

Propofol and Thiopental
-Provide decrease in CMRO2
-Provide quick, deep induction
(neuroprotective effects)

Front 23

Is it better to give a low, medium or high dose of induction agent to a patient with increased ICP? why?

Back 23

Better to start low-you can always give more. The goal is to provide induction but maintain appropriate CPP

Front 24

What effects do VA have on ICP? What actions are appropriate by the anesthetist when turning on VA?

Back 24

Halogenated agents will cause vasodilation of the cerebral vasculature but Small amount of agent is used to deepen anesthetic prior to intubation, so hyperventilate(RR 20-30) pt to lower CO2 and decrease cerebral blood flow

Front 25

What is the physiologic response to direct laryngoscopy?

Back 25

DL is very stimulating -> increased HR and BP will increase ICP

Front 26

What adjuncts are used to provide blunting of airway reflexes prior to intubation of pt with increased ICP?

Back 26

Fentanyl 5-10 mcg/kg
Lidocaine 0.5-1.0 mcg/kg (avoid if seizure risk)

Front 27

Which muscle relaxant should be avoided in a patient with increased ICP?

Back 27

Succinylcholine-it causes a transient increase in ICP-avoid if possible

Front 28

Which muscle relaxant is the best choice for a pt with increased ICP?

Back 28

Choose any non-depolarizing muscle relaxant according to pt hx

Front 29

If you attempt to intubate prior to full effect of the muscle relaxant in a pt with increased ICP, what do you risk?

Back 29

Coughing, which will sharply increase ICP

Front 30

What is the overall goal while intubating a patient with increased ICP?

Back 30

Minimal change in VS!

Front 31

How can the anesthetist ensure airway reflexes are blunted prior to intubation in a pt with increased ICP?

Back 31

1) DEEP level of anesthesia
2) Appropriate MUSCLE BLOCKADE
3) Attenuation of AIRWAY REFLEXES

Front 32

How can the anesthetist control BP and HR during intubation?

Back 32

Recognize that DL is stimulating only briefly - Use short acting agents-stay off the roller coaster- Esmolol,and small doses of induction agents (propofol and thiopental) will lower heart rate and BP for short periods of time

Front 33

What positioning issues are associated with surgery on pt with increased ICP?

Back 33

Position appropriately to promote venous drainage and drainage of CSF
-head in neutral position so as to not compress jugular veins
-HOB increased to promote drainage

Front 34

Where will the OR table be in relation to the anesthetist for surgery on pt with increased ICP Why is this of special concern?

Back 34

bed will be 90-180 degrees from anesthetist. A loss of airway or disconnect will cause increased CO2, resulting in increased ICP.