Mod11: Interventional Neuroradiology - Anesthesia Technique

Question 1

_{Anesthesia for Radiology & Radiation Therapy - Interventional Neuroradiology}

Which anesthetic technique can be used here?

Answer 1

Conscious sedation

General anesthesia

Sleep-awake-sleep” technique

Question 2

_{Interventional Neuroradiology - Anesthetic Technique}

Which variations of conscious sedation could be used here?

Answer 2

Midazolam/Fentanyl combination

^{(could be done by RN)}

Propofol infusion

^{(Anesthesia required - Keep pt comfortable and Not obstructing)}

Question 3

_{Interventional Neuroradiology - Anesthetic Technique}

General anesthesia is more commonly requested by neuroradiologists. Which airway devices could be used? What are the most commonly used induction agents

Answer 3

ET intubation and PPV most common

LMA suitable alternative

STP/Propofol most commonly used induction agents

^{(Caution with Propofol: be able to titrate it to where the pt is asleep an not obstructing)}

Question 4

_{Interventional Neuroradiology - Anesthetic Technique}

What is the “Sleep-awake-sleep” technique?

Answer 4

Keep the patient asleep until catheter is in the right position

Pt is awaken for neurologic testing

Pt put back to sleep for the procedure to be completed

Question 5

_{Interventional Neuroradiology - Anesthetic Technique}

Which intra-procedure neuro exam is possible with the “Sleep-awake-sleep” technique? What are the benefits of performing that exam?

Answer 5

SAFE: Superselective Anesthesia Functional Exam

Performed prior to embolization to determine if catheter is positioned in a vessel that supplies an eloquent area of the brain or spinal cord (speech/language areas)

Question 6

_{Interventional Neuroradiology - Anesthetic Technique}

Infusions commonly used for “Sleep-awake-sleep” technique

Answer 6

Propofol/Remifentanil or

Propofol/Alfentanil

Question 7

_{Interventional Neuroradiology - Anesthetic Technique}

True or False: invasive monitoring is less used in interventional neuroradiology than in neurosurgical procedures

Answer 7

True

Question 8

_{Interventional Neuroradiology - Anesthetic Technique}

Benefits of Arterial line in Interventional Neuroradiology procedures:

Answer 8

Continuous BP monitoring

BP manipulation as requested by neuroradiologist

Question 9

_{Interventional Neuroradiology - Anesthetic Technique}

What are the benefits of “controlled hypotension”? Which drugs are used to acheive it?

Answer 9

Facilitate embolization AVM

Esmolol, labetalol, metoprolol, hydralazine commonly used

Question 10

_{Interventional Neuroradiology - Anesthetic Technique}

Benefits of Moderate hypertension and drug of choice

Answer 10

Reduction of cerebral ischemia and cerebral vasospasm

Phenylephrine is the drug of choice

Question 11

_{Anesthetic for Radiology & Radiation Therapy - CT & MRI}

Pain considerations with CT & MRI: are these painful? If not, why is pain a concern? why is anesthesia needed at times?

Answer 11

Relatively painless

There is an absolute requirement for motionless patient

Question 12

_{Anesthetic for Radiology & Radiation Therapy - CT & MRI}

Why would anesthesia be required for these otherwise non-invasive procedures?

Answer 12

Patient must remain motionless

Question 13

_{Anesthetic for Radiology & Radiation Therapy - CT & MRI}

What are anesthetic requirements for adults and children in these areas?

Answer 13

Sedation/general anesthesia

(For children & Adults with _neurologic disorder_s)

No sedation

(For most adults)

Question 14

_{Anesthetic for Radiology & Radiation Therapy - CT & MRI}

Why must acute trauma patients be stabilized before transported to radiology department?

Answer 14

They may otherwise develop:

Cardiac arrest - Raised ICP - LOC - Hemorrhagic shock

Question 15

_{Anesthetic for Radiology & Radiation Therapy - CT Scan}

What’s the purpose and the characteristics of Stereotactic-guided surgery?

Answer 15

For biopsy or aspiration of intracranial mass

Performed using CT scanning to minimize injury to adjacent structures

Radiolucent frame placed around head and held in place by inserting pins into skull → PAINFULL

(Deep Brain stimulator is an example of Stereotactic-guided surgery include and is helpful in Parkinson’s Dz)

Question 16

_{Anesthetic for Radiology & Radiation Therapy - CT Scan}

What are Anesthetic Considerations for Stereotactic-guided surgery?

Answer 16

Deep sedation or General with LA

Proceed with caution while sedating those with intracranial HTN

Question 17

_{Anesthetic for Radiology & Radiation Therapy - CT Scan}

What is the most stimulating and most Painfull part of Stereotactic-guided surgery?

Answer 17

Radiolucent frame placement

Frame placed around head and held in place by inserting pins into skull

Done in CT or MRI - Propofol used

Open Craniotomy done in the OR with the patient awake

Question 18

_{Anesthetic for Radiology & Radiation Therapy - CT Scan}

Why should we Proceed with caution while sedating those with intracranial HTN during Stereotactic-guided surgery?

Answer 18

….

Question 19

_{Anesthetic for Radiology & Radiation Therapy - CT Scan}

Which complication is associated with Frame during Stereotactic-guided surgery? How shoould it be managed?

Answer 19

Airway Oclusion by Frame!!!

Be prepared for rapid airway control should need arise

^{LMA - FOI - Removal of frame}

Question 20

_{Anesthetic for Radiology & Radiation Therapy}

What’s the science behind Magnetic Resonance Imaging (MRI)?

Answer 20

Uses Radiofrequency waves and

a Strong magnetic field rather than x-rays

Question 21

_{Anesthetic for Radiology & Radiation Therapy - MRI}

How long does it take to establish Magnetic field?

Answer 21

Several days

Question 22

_{Anesthetic for Radiology & Radiation Therapy - MRI}

True or False: The Magnetic field is CONSTANTLY present

Answer 22

True

Question 23

_{Anesthetic for Radiology & Radiation Therapy - MRI}

Which delineates the peripheral field around the MRI magnet, and inside which equipment malfunction is a common risk?

Answer 23

“Gauss lines”

Question 24

_{Anesthetic for Radiology & Radiation Therapy - MRI}

What is measured at “Gauss lines”?

Answer 24

Strength of magnetism

(↓ with ↑ distance from center magnet)

Question 25

_{Anesthetic for Radiology & Radiation Therapy - MRI} What are adverse effects of MRI due to human exposure to the magnetic field?

Answer 25

**None** has been described!!!

Question 26

_{Anesthetic for Radiology & Radiation Therapy - MRI} Why must a Rigorous checklist be completed by the patient & staff before entering the MRI?

Answer 26

Serious risk of **injury** or even **DEATH**!!! with presence of _ferrometallic foreign bodies_ ^{(cerebral aneurysm clips/pacemakers/AICD’s)}

Question 27

_{Anesthetic for Radiology & Radiation Therapy - MRI} Why MUST we CHECK TO DETERMINE IF ANY PIECE OF EQUIPMENT IS MRI COMPATIBILE BEFORE TAKING it INTO SCANNING ROOM?

Answer 27

Anesthesia machine, equipment, monitors, infusion pumps, laryngoscopes, gas cylinders all can become **LETHAL PROJECTILES** if brought _within the **50 gauss line**_

Question 28

_{Anesthetic for Radiology & Radiation Therapy - MRI} Why should a Nonferrous or fiberoptically cabled pulse oximeters be used instead of a Standard pulse?

Answer 28

**Burns!!!** Standard pulse ox work, but may produce burns

Question 29

_{Anesthetic for Radiology & Radiation Therapy - MRI} Why do we have lots of EKG artifacts in MRI

Answer 29

EKG sensitive to **changes in magnetic signal**

Question 30

_{Anesthetic for Radiology & Radiation Therapy - MRI} Why should EKG Electrodes be placed close together & insulated from skin?

Answer 30

To prevent thermal injury

Question 31

_{Anesthetic for Radiology & Radiation Therapy - MRI} Most infusion pumps can be used in MRI, but how far must they be placed?

Answer 31

Outside **30 gauss line** (extension tubing available - Plan for more IV anesthetic agents to fill the extension tubing)

Question 32

_{Anesthetic for Radiology & Radiation Therapy - MRI} Which takes longer? MRI or CT scan?

Answer 32

MRI takes up to 30” May take much longer if anesthesia envolved (vs. 5” with CT scan)

Question 33

_{Anesthetic for Radiology & Radiation Therapy - MRI} Why should magnetic coils be avoided?

Answer 33

Magnetic coils **emit heat** adding to discomfort

Question 34

_{Anesthetic for Radiology & Radiation Therapy - MRI} Why should Both patient and anesthesia provider wear hearing protection?

Answer 34

The MRI room is loud Emits up to 90dB

Question 35

_{Anesthetic for Radiology & Radiation Therapy - MRI} Once scan starts, no one can leave or enter room. What do you do in case of emergency?

Answer 35

**Stop scan** _Remove pt from scanner_ **Resuscitation** attempts to occur **outside** ^{(unless MRI compatible)}

Question 36

_{Anesthetic for Radiology & Radiation Therapy - CT & MRI} What percent of adults require sedation to tolerate CT & MRI\*?

Answer 36

14% _{MRI>CT d/t length Most of the sedation given by non-anesthesia providers Could be oral or IV sedation Anesthesia providers called in for more complicated cases}

Question 37

_{Anesthetic for Radiology & Radiation Therapy - CT & MRI} Which pediatric population will require sedation or GA? How is sedation provided?

Answer 37

**Children** _under 5 years of age_ **Oral sedation** (usually higher ASA) or **IV sedation** used

Question 38

_{Anesthetic for Radiology & Radiation Therapy - CT & MRI} What percentage of pediatric pts will have some type of adverse event?

Answer 38

22% | (e.g., a drop in pulse ox, Nausea)

Question 39

_{Anesthetic for Radiology & Radiation Therapy - CT & MRI} What are anesthetics options for pediatric pts during CT & MRI?

Answer 39

**Deep sedation** with propofol infusion with or w/o midazolam also successful **General anesthesia** a/w low incidence of adverse effects **LMA** very common unless contraindicated