Usc2013 Anesthesia In Remote Locations - Lecture

Front 1

What are some remote locations for anesthesia?

Back 1

Radiology
Lithotrypsy Suites
CA Center - radiation
MRI Suite
Cath Lab
Electroconvulsive Therapy

Front 2

What are some problems with anesthesia in remote locations?

Back 2

POOR DESIGN
---> No room to work, etc

UNDEFINED LINES OF COMMUNICATION
--> Need to establish these lines to get the resources you need, etc.

PATIENT CARE FLOW ISSUES
---> Need to find out exactly where recovery area is, where pt is coming from, where pt is going, etc.

EQUIPMENT UNAVAILABLE OR UNFAMILIAR
--> Stocked carts may not be stored on site.
--> Anesthesia machines may be old or unfamiliar. Need to do a full equipment check.

UNCLEAR IDENTITY OF ROLES/ QUALIFICATIONS
--> Clarify these before sx.

Front 3

MRI Anesthesia machines are made of ...

Back 3

MRI Anesthesia machines are made of non-ferrous materials.

Front 4

If you lack a scavenging system in your OR what should you do?

Back 4

Do a TIVA if possible instead of a general to prevent leakage of gas.

Front 5

What three things should you always know the location of in every remote location?

Back 5

Crash carts
Exits
Fire Extinguishers

Front 6

Standards of CAre in remote locations...are...

Back 6

same as in OR!!

Front 7

Closed claims studies show that claims involving care in remote locations are primarily _____ cases.

Back 7

MAC Cases and Inadequate Oxygen/ Ventilation

Could have been due to:
* Loss of airway with no intubation equipment nearby
* Inadequate TIVA sedation during sx and pt moved.
* Hypoventilation undetected due to no ETCO2 monitor.


So MAC sedation and lack of capnograph caused the most closed claims.

Front 8

Radiation exposure decreases with what intensity?

Back 8

Radiation exposure decreases with the inverse square of the distance from the emitting source.

Therefore, the further you move away, the less exposure you have.

Front 9

How can you protect yourself from radiation?

Back 9

*STEP AWAY!!!
Lead Aprons with thyroid shields.
* Lead glass screen
* 1-2 meters from radiation source
* Clear communication between radiology// anesthesia (make sure they ask you before pressing the button).

Front 10

What things emit radiation in the hospital?

Back 10

Flouroscopy
CT
XRAY
Radioactive Substances.

Front 11

Physics unit of measure of biologic radiation dose is the

Back 11

seivert and REM

1 seivert = 100 REM

Front 12

What is the annual average dose of naturally occuring radioactive materials?

Back 12

3 milli-sievert (mSv) = 300 mrem

Front 13

How much radiation is in a chest xray?

A CT Scan?

Back 13

XRAY: 0.04 mSv = 40 mrem

CT Scan: 2.0 mSv = 200 mrem

Front 14

What is the federally mandated annual occupational exposure limit for radiation?

Back 14

50 mSv = 5000 mrem

Front 15

What parts of the body are most vulnerable to radiation?

Back 15

Endocrine Organs
Eyes
Thyroid Gland

Front 16

What adverse reaction can occur with Contrast Agents in diagnostic radiology procedures?

Back 16

Anaphylactic Reactions

MILD
--> Nausea, Pruritus, Diaphoresis

MODERATE
--> Faintness, emesis, urticaria (hives), laryngeal edema, bronchospasm

SEVERE
--> Seizures, hypotensive shock, respiratory arrest, cardiac arrest.


( Also, the contrast can diurese the pt, so you need to adequately hydrate the pt.)

Front 17

How should you treat anaphylaxis from contrast dye?

Back 17

AGGRESSIVELY!!! These rxns cause massive vasodilation via histamine release from mast cells, bradykinen, serotonin release.

OXYGEN
IV FLUIDS
EPINEPHRINE!!!

Front 18

How can you prevent anaphylactic reaction to contrast dye?

Back 18

Steroids (40 mg of prednisone)

Antihistamine (Benedryl 50 mg)

20mg of famotidine

Front 19

what part of contrast dye causes the anaphylactic reaction?

Back 19

Iodine

Front 20

What contrast agents used in MRI have a much lower risk for anaphylactoid reactions?

Back 20

Gadolinium Contrast Agents.

Front 21

In NONINVASIVE Procedures, what is the purpose of anesthesia?

Back 21

* Provide immobility

* Adequate oxygenation/ perfusion

* Pain/ Anxiety Management

Front 22

Do most adults need sedation for noninvasive procedures?

Back 22

No.

Instruction and preparation only.

Front 23

Do children need sedation for noninvasive procedures?

Back 23

Yes. They need sedation

Therefore:
* Monitor SpO2, Capnography
* Give supplemental O2
* Use a propofol infusion with supplemental opiods, benzos, precedex, etc.

Front 24

When giving supplemental O2 during noninvasive procedures, where should the O2 be connected?

Back 24

To a seperate flowmeter instead of the common gas outlet on the machine. You want to save that for in case of an emergency.

Use humidified O2 if long procedures.

Front 25

What are some problems with anesthesia that are encountered in MRI?

Back 25

*YOu have to anesthetize just outside the room and then transfer all non-ferrous materials into the magnet room.

* Supply cart is outside the room

* Anesthesia machine is made of non-ferrous materials and is 1/2 the size of a normal machine. It is different and unfamiliar.

* You must have extensions on everything including IV tubing and breathing circuits.

* Capnographs might not function well because they are not used alot.

* Might not have scavenging avaliable.

Front 26

What are the goals of anesthesia with Invasive/ Interventional Radiology?

Back 26

* Patient Immobility
* Physiological Stability
* Decrease risk for bleeding (check ACT and coags before procedure).
* Maintain Airway and ventilation
* Readiness for adverse events
* Smooth, rapid emergence (exubate deep)

Front 27

Criteria for a Deep extubation

Back 27

* Suction pt well before extubation
* Pt should be in stage III
* Pt should have even, spontaneous respirations.

Front 28

How can you minimize couging and bucking on a tube as a pt wakes up after invasive procedures?

Back 28

Morphine
Precedex
LTA kit to vocal cords

Front 29

What is the goal of heparin therapy (70U/kg) prior to invasive procedures?

Back 29

You want to prolong the ACT baseline 2-3 fold.

Note: if clot times too long, may be asked to give protamine sulfate (1mg/100U heparin) at discretion of radiologist.

Front 30

What is the reversal agent for Heparin?

Dose?

Back 30

Protamine Sulfate

1 mg for every 100 u of heparin.

This is given at the discretion of the radiologist.

Front 31

What is the goal of anesthesia with Radiation Therapy?

Back 31

* Patient Immobility is the goal. - so that radiation can be precisely targeted.

*May involve daily treatments, so you need FAST ONSET, SHORT DURATION drugs.

*May have to transport pt to diff areas for radiation treatment and you might have to monitor your pt outside the room with a remote monitor.

Front 32

What is Electroconvulsive Therapy?

Back 32

* Electrically induced seizure that causes a Grand Mal Seizure. The seizure releases NT's.

* This therapy is reserved for use after failure of pharmacologic therapy for depression, schizophrenia.

* The seizure must last > 20 seconds to be effective.

* Put a bite block in tongue to protect the tongue.

Front 33

What types of anesthesia are useful with ECT and why?

Back 33

The impact of anesthesia on the seizure duration must be considered.

* BARBITUATES like Brevitol are short acting and therefore good for ECT.

Methohexital (Brevitol) 1.0 mg/kg
Pentothal 1-2 mg/kg

* Propofol will SHORTEN the seizure duration, but if you add opiods this will be corrected.

* Etomidate will allow a longer seizure than propofol, cause minimal CV and resp depression and is therefore a good drug to use. However, it can't be use for mx cases because it can cause adrenocortico-suppression.

*Benzos should be AVOIDED in ECT because they will shorten the duration of the seizure.

Front 34

What is the physiologic response to the tonic phase of a seizure?

Back 34

Profound parasympathetic stimulation causing BRIEF bradycardia.

Front 35

What is the physiologic response to the clonic phase of a seizure?

Back 35

BRIEF Sympathetic Stimulation
--> HTN
--> Tachycardia
--> Cardiac Dysrhytmias

...You can give Esmolol to manage the BRIEF SNS response during the clonic phase because esmolol is rapidly hydrolysed by plasma cholinesterases.

Front 36

What are some Cath Lab Procedures:

Back 36

* DIAGNOSTIC INTERVENTIONAL
--> Anesthetic management can be challenging because most of these patients have advanced cardiac disease.

* ICD (DEFIBRILLATOR) PLACEMENT
--> Sedation is needed for repeated test of the device.

* TEE/ CARDIOVERSION
--> Requires brief sedation/ amnesia, assisted/ controlled ventilation until back to baseline.

Front 37

What is extracorporeal shock wave lithotripsy?

Back 37

The use of shock waves to pulverize renal and ureteral calculli.

May involve immersion in water, which can cause monitoring, airway access issues.

There is a risk for cardiac dysrhythmias- should have synchronous shock 20 msec after the R wave, which corresponds to the absolute refractory period.

Front 38

What is Dexmedetomidine (Precedex)

Back 38

An alpha 2 antagonist that is a useful sedative because it have no respiratory depression effects.

Downside - it can lower blood pressure.

Front 39

Intracranial imaging is best done by ...

Back 39

Head CT

Front 40

Does MRI have ionizing radiation?

Back 40

No

Front 41

What are some things not allowed in MRI?

Back 41

Orthopedic hardware
Cardiac pacemakers
wire-reinforced epidural catheters.
Pulmonary artery catheter with a temperature wire.

Pulse Oximeter - need to get an MRI compatible one.

Front 42

What metals are magnetic and what metals are not and can be used in MRI?

Back 42

Magnetic: Nickel, Cobalt

Non-magnetic: Aluminum, copper, silver, titanium

Front 43

When pt is in MRI, where is YOUR non-ferrous anesthesia station?

Back 43

Just outside the room in case something goes wrong it is right there.

Front 44

For pts with emergency cerebral thrombolysis or patients with aneurysmal subarachnoid hemorrhage in whom vasospasm has developed, what do you want their BP to be?

Back 44

BP needs to be higher than normal to maintian perfusion to the brain.

Any case of occlusive cerebrovascular disease should require higher BP than normal.

Front 45

If your pt a recently ruptured intracranial aneurysm, recently obliterated intracranial AV malformation, or S/P cerebrovascular angioplasty adn stent placement, what do you want their BP to be?

Back 45

Lower then normal.

These pts are at risk for Post treatment cerebral hyperperfusion injury adn require careful control of SBP after sx.

Front 46

ACT is needed during intracranial catheter navigation to prevent thromboembolic complications. What drug should you give and what are your parameters?

Back 46

Heparin (70U/kg)

You want the baseline activated clotting time to be increased by 2 or 3 times normal.

Hourly monitoring of ACT to prevent clotting.

Front 47

What types of anticoagulants are given when placing intra-arterial stents?

Back 47

Antiplatelet agents:

Aspirin,
Ticlopidine
Antagonists to glycoprotein IIb/ IIIa receptors.

These are used in conjunction with heparin.

These have no antidotes, have to give plts to reverse them.

Front 48

GammaKnife Radiation

Back 48

simultaneously directs mx pencil thin gamma ray beams into the targeted area.

Front 49

Cyber Knife Radiation

Back 49

Delivers a large # of pencil thin gamma-ray beams to provide lethal radiation.

It delivers them in a sequence of several hundred beams from a robat that moves around the pt and shoots the beams at cancer regions from diff directions

Front 50

Anesthesia for Gamma Knife Radiation

Back 50

* GA r sedation for placement of head frame.

* Sedation during MRI/ CT

* Maintain anesthesia in RR while pt waits for radiation

* Anesthesia during radiation.

Front 51

Anesthesia for Cyber Knife procedures

Back 51

* Prior surgical implantation of radioopaque markers.

* Keep anesthesia machine, drug cart, and all tubes/ hoses away from the robot arm.

* must stay outside the room so you don't get any radiation.

*monitoring via remote control videos.