Mod11: Anesthetic Considerations for Radiology & Radiation Therapy Flashcards
Anesthetic Considerations for Radiology & Radiation Therapy
Why must caution be used with IV contrast agents during Radiology & Radiation Therapy procedures?
It’s not uncommon to see people with IV contrats allergies
Anesthetic Considerations for Radiology & Radiation Therapy
Why is allergy to IV contrast mostly associated with older agents?
Older ionized contrast media were hyperosmolar and toxic
Pts who received IV contrast in the 70s or 80s and had a reaction, will have it documented in their chart as an “allergy”.
These pts may benefit from Benadryl or a steroid pretreatment
If history of Anaphylactic reaction or a more recent history of allergic raction, talk to the physician about maybe trying out something else besides IV contrast (e.g., cancelling the procedure, non using contrast at all)
Anesthetic Considerations for Radiology & Radiation Therapy
How do new IV contrast agents differ from the older agents?
Newer non-ionized contrast media have lower osmolality and improved side-effects
Anesthetic Considerations for Radiology & Radiation Therapy
Predisposing factors to adverse reactions from contrast media include a history of:
Bronchospasm - Allergy - Cardiac disease
Hypovolemia - Hematologic disease - Renal dysfunction
Extremes of age - Anxiety
Medications (Beta-blockers, aspirin, and NSAIDs)
Anesthetic Considerations for Radiology & Radiation Therapy
Why is a history of Bronchospasm a Predisposing factor to adverse reactions from contrast media?
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Anesthetic Considerations for Radiology & Radiation Therapy
Why is a history of Allergy a Predisposing factor to adverse reactions from contrast media?
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Anesthetic Considerations for Radiology & Radiation Therapy
Why is a history of Cardiac disease a Predisposing factor to adverse reactions from contrast media?
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Anesthetic Considerations for Radiology & Radiation Therapy
Why is a history of Hypovolemia a Predisposing factor to adverse reactions from contrast media?
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Anesthetic Considerations for Radiology & Radiation Therapy
Why is a history of Hematologic disease a Predisposing factor to adverse reactions from contrast media?
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Anesthetic Considerations for Radiology & Radiation Therapy
Why is a history of Renal dysfunction a Predisposing factor to adverse reactions from contrast media?
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Anesthetic Considerations for Radiology & Radiation Therapy
Why is Extremes of age a Predisposing factor to adverse reactions from contrast media?
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Anesthetic Considerations for Radiology & Radiation Therapy
Why is a history of Anxiety a Predisposing factor to adverse reactions from contrast media?
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Anesthetic Considerations for Radiology & Radiation Therapy
Why is a history of using some Medications (Beta-blockers, aspirin, and NSAIDs) a Predisposing factor to adverse reactions from contrast media?
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Anesthetic Considerations for Radiology & Radiation Therapy
How does a mild reaction to IV contrast agents manifest?
Nausea - Perception of warmth - Headache
Itchy rash - Mild urticaria
Not really considered a reaction; more of a side effect from the contrast
Anesthetic Considerations for Radiology & Radiation Therapy
How does a Severe reaction to IV contrast agents manifest?
Arrhythmias - Bronchospasm - Dyspnea - Chest pain
Feeling faint - Rigors - Vomiting - renal failure
Severe urticaria
Anesthetic Considerations for Radiology & Radiation Therapy
How does a Life-threatening reaction to IV contrast agents manifest?
Arrhythmias - Cardiac arrest
Glottic edema/bronchospasm - Pulmonary edema
Seizures/unconsciousness.
Anesthetic Considerations for Radiology & Radiation Therapy
How are reactions to IV contrast treated?
O2 - Bronchodilators - Epinephrine
Corticosteroids - Antihistamines - Intubation
Circulatory support with IV fluids/pressors
Also refer to lecture on Anaphylaxis reaction
Anesthetic Considerations for Radiology & Radiation Therapy
Contrast-induced nephropathy accounts for what % of hospital-acquired renal failure
10%
Anesthetic Considerations for Radiology & Radiation Therapy
Contrast-induced nephropathy is more common in which clinical conditions?
Renal insufficiency
DM
NSAIDs
Anesthetic Considerations for Radiology & Radiation Therapy
How could the risk of Contrast-induced nephropathy be reduced in susceptible patients?
Adequate hydration
Monitoring U/O
Low osmolarity contrast media
Administer NaHCO3 IV infusion 1hr before contrast administration
Anesthetic Considerations for Radiology & Radiation Therapy
Radiation exposure is a unique hazard. What could it lead to?
Leukemia and fetal abnormalities
Anesth. Considerations for Radiology & Radiation Therapy - Radiation exposure
Why are providers required to wear dosimeters?
Measure amount of radition providers are exposed to
Turned back in monthly
Allows to identify locations with excessive emissions
Allows for reassignment of providers with elevated readings
Anesth. Considerations for Radiology & Radiation Therapy - Radiation exposure
What is the maximum amount of radiation a provider should be exposed annually?
50 mSv or 5,000 milirams
Anesth. Considerations for Radiology & Radiation Therapy - Radiation exposure
Which equipments should be used for the purpose of protection from ionizing radiation each time radition exposure is and anticipate?
Lead apron (front and back)
Protective goggles
Thyroid shield
Leaded glass screens
Anesth. Considerations for Radiology & Radiation Therapy - Radiation exposure
Which eye condition could result from exposure to radition overtime if Protective goggles are not used?
Cataract
Anesthesia for Radiology & Radiation Therapy - Angiography (Spinal/Cerebral)
What is the typical access for Angiography (Spinal/Cerebral)?
Femoral artery
Anesthesia for Radiology & Radiation Therapy - Angiography (Spinal/Cerebral)
In which cases would the Femoral vein be accessed for Angiography?
During AVM imaging or
Dual Venous abnormalities
Anesthesia for Radiology & Radiation Therapy - Angiography (Spinal/Cerebral)
Since Diagnostic angiography is only associated with minimal discomfort, what are anesthetic requirements?
Local with or w/o light sedation
by non anesthesia providers
Anesthesia for Radiology & Radiation Therapy - Angiography (Spinal/Cerebral)
What are the anesthetic requirements for angiograpgy procedure in pts unable to tolerate procedure (neuro disorder, severe pain, lengthy procedure)?
Deep sedation
General anesthesia
Anesthesia provider must be present
Anesthesia for Radiology & Radiation Therapy - Angiography (Spinal/Cerebral)
What physiological changes accompany injection of IV contrast dye?
Discomfort, burning, pruritus around face
(often masked by anesthesia)
Hypotension & bradycardia
(if reaction)
Anesthesia for Radiology & Radiation Therapy - Angiography (Spinal/Cerebral)
During angiography, when pt is placed on moving gantry, and the C-arm is used to track catheter from groin into cerebral vessels, anesthesia provider should carefully monitor extensions cords/tubing to prevent dislodgement of which equipments?
Breathing circuits
IV tubing
Monitors
Caution injury occurring to pt from radiology equipment
Anesthesia for Radiology & Radiation Therapy - Angiography (Spinal/Cerebral)
True or False: EKG electrodes may interfere with imaging during spinal angiography.
True
Anesthesia for Radiology & Radiation Therapy
Interventional Neuroradiology is used for the the Endovascular treatment of which neurosurgical conditions?
Intracranial aneurysms with detachable coils
Arteriovenous malformations
Anesthesia for Radiology & Radiation Therapy - Interventional Neuroradiology
What size sheath is used to gain Arterial access via the femoral artery during Interventional Neuroradiology?
6 - 7 French sheath
Anesthesia for Radiology & Radiation Therapy - Interventional Neuroradiology
Besides Femoral artery access, what other access can be used for interventional Neuroradiology procedures?
Carotid or axillary artery
Possible but rare
Anesthesia for Radiology & Radiation Therapy - Interventional Neuroradiology
What happens as the catheter is advanced?
Guide catheter is advanced through sheath
Road mapping technique employed
Boluses of IV contrast dye injected to outline vascular anatomy
Guide advancement of microcatheters for placement of embolic materials into aneurysm or feeding vessels of AVM
Anesthesia for Radiology & Radiation Therapy - Interventional Neuroradiology
When and how long is anticoagualtion required with Interventional Neuroradiology procedures?
During & 24hrs after procedure
Anesthesia for Radiology & Radiation Therapy - Interventional Neuroradiology
When Heparin is used after the procedure, what’s the protocol?
Heparin 3000-5000 units IV initial bolus, and
1000 units/hr to maintain ACT at 2.5 times pt’s baseline
Anesthesia for Radiology & Radiation Therapy - Interventional Neuroradiology
What are advantages of Interventional Neuroradiology procedures?
Avoids need for surgical craniotomy
Reduces cognitive impairment and frontotemporal brain damage
Reduces the risk of spontaneous recurrent hemorrhage following subarachnoid hemorrhage
Considered upstream surgical interventions vs a downstream surgical interventions which are interventions after the event already happened
Anesthesia for Radiology & Radiation Therapy - Interventional Neuroradiology
What are complications of Interventional Neuroradiology procedures?
Hematoma/hemorrhage form femoral artery puncture
Air embolism via femoral artery sheath
Bradycardia/transient asystole during carotid artery stent placement
Pulmonary embolism (acrylic glue used - smells like garlic)
Intracranial hemorrhage - Thromboembolic stroke
Anesthesia for Radiology & Radiation Therapy - Interventional Neuroradiology
What is the most likely cause of Bradycardia/transient asystole during Interventional Neuroradiology procedures?
Vagal stimulation from carotid artery stent placement
Anesthesia for Radiology & Radiation Therapy - Interventional Neuroradiology
What are initial resuscitation intervevention in the Acute management of neurologic complications?
(What would you do if you notice a change when the pt is under light anesthesia or when she is waking up?)
Communicate with radiologists
Call for assistance
Secure airway & hyperventilate with 100% O2
Determine if problem hemorrhagic or occlusive
Anesthesia for Radiology & Radiation Therapy - Interventional Neuroradiology
How do you treat a Hemorrhagic complication during an Interventional Neuroradiology procedure?
Immediate heparin reversal
(1mg protamine for each 100U heparin given)
Low normal pressure
Anesthesia for Radiology & Radiation Therapy - Interventional Neuroradiology
How do you treat a Occlusive complication during an Interventional Neuroradiology procedure?
Deliberate hypertension titrated to neurologic examination
Angiography, or
Physiologic imaging studies (TCD, CBF)
Anesthesia for Radiology & Radiation Therapy - Interventional Neuroradiology
How much Protamine is given per units of Heparin for Immediate heparin reversal during an Interventional Neuroradiology?
1mg Protamine for each 100U heparin given
Anesthesia for Radiology & Radiation Therapy - Interventional Neuroradiology
While waiting for definitive tx of acute complications during Interventional Neuroradiology procedure, what could be done in the interim?
Head up 15˚ in neutral position
Titrate ventilation to a PaCO2 of 26-28mmHg
Mannitol 0.5mg, rapid IV
Anticonvulsants
Dilantin 50mg/min (slowly)
Phenobarbital
Titrate STP infusion to EEG burst suppression
Hypothermia (allow temp to rapidly ↓ to 33-34˚C)
Consider dexamethasone 10mg
Anesthesia for Radiology & Radiation Therapy - Interventional Neuroradiology
In the acute management of neurologic complications during Interventional Neuroradiology procedures and as part of further resuscitation efforts, how should the head be positionned?
Head up 15˚ in neutral position
Anesthesia for Radiology & Radiation Therapy - Interventional Neuroradiology
In the acute management of neurologic complications during Interventional Neuroradiology procedures and as part of further resuscitation efforts,
Titrate ventilation to a PaCO2 of
26-28mmHg
Anesthesia for Radiology & Radiation Therapy - Interventional Neuroradiology
In the acute management of neurologic complications during Interventional Neuroradiology procedures and as part of further resuscitation efforts, what dose of Mannitol would you administer?
0.5mg, rapid IV
Anesthesia for Radiology & Radiation Therapy - Interventional Neuroradiology
In the acute management of neurologic complications during Interventional Neuroradiology procedures and as part of further resuscitation efforts, which anticonvulsants would administer?
Dilantin 50mg/min (slowly)
Phenobarbital
Anesthesia for Radiology & Radiation Therapy - Interventional Neuroradiology
In the acute management of neurologic complications during Interventional Neuroradiology procedures and as part of further resuscitation efforts, what would you titrate STP infusion to?
EEG burst suppression
Anesthesia for Radiology & Radiation Therapy - Interventional Neuroradiology
In the acute management of neurologic complications during Interventional Neuroradiology procedures and as part of further resuscitation efforts, what’s your Hypothermic goal and strategy?
Allow temp to rapidly ↓ to 33-34˚C
Anesthesia for Radiology & Radiation Therapy - Interventional Neuroradiology
In the acute management of neurologic complications during Interventional Neuroradiology procedures and as part of further resuscitation efforts, which dose of dexamethasone would you administer?
10mg
Anesthesia for Radiology & Radiation Therapy - Interventional Neuroradiology
In the acute management of neurologic complications during Interventional Neuroradiology procedures and as part of further resuscitation efforts, why would you administer steroids?
To decrease swelling