Contrast Material and Medications in Radiology
Leeanne Langston, BS, RRA, RPA, RT(R) The government agency responsible for ensuring that drugs marketed in the US are safe and effective Food and Drug Administration (FDA) The government agency responsible for enforce the controlled substances laws and regulations Drug Enforcement Agency (DEA) What’s in a name?
Generic or Brand?
Brand name: refers to the trade name developed by the company (Tylenol)
Generic name: is the official name of a drug (Acetaminophen) Generic drugs are copies of brand- name drugs, they must have the exact same pharmacological effects as their counterparts Common Ways of Administering Contrast or Meds
oral: by mouth sublingual: under the tongue enteric: delivered directly into the stomach nasal: sprays or pumps parenteral: injection or infusion (IM, IV, SC) rectal: suppository inserted into the rectum Intramuscular: inject at 90 degrees Intravenous injection: most common site is median cubital vein Cutaneous injection: “sub-cu” absorption is slow Intrathecal injection: administering contents w/ CSF
Local Anesthetics
Generic Name Trade Name Onset Duration of Action (min) Procaine Novocain moderate 30-60 hydrochloride
Lidocaine Xylocaine rapid 80-120 hydrochloride
Bupivacaine Marcaine Longest 180-360 hydrochloride (2–10 min)
Ropivacaine Naropin moderate 140-200 hydrochloride Lidocaine (Xylocaine) Bupivacaine (Marcaine)
Quicker onset Slower onset
Short duration Longer duration
Max safe dose 300mg Max safe dose 150mg (500mg w/ epinephrine) (225mg w/epinephrine)
CNS toxicity w/ excessive cardio toxic doses
Can be mixed w/ sodium Can be mixed w/ bicarbonate to stinging corticosteroid for longer (short term) relief Contraindications and Risks
Both have very low risk of allergic reaction Previous allergy to Novocain is NOT contraindication to use Lidocaine Moderate/Conscious Sedation
ASA defines moderate sedation as: a minimally depressed level of consciousness induced by the administration of pharmacological agents in which the patient retains a continuous and independent ability to maintain protective reflexes, a patent airway, and the ability to be aroused by physical or verbal stimulation. Physical status classifications used by the ACR-SIR based on the ASA guidelines
ASA Guidelines ACR-SIR Guildelines
Class 1: normal healthy Class 1 & 2: low risk, no patient further recommendations
Class 2 & 3: mild/moderate Class 3 & 4: may require systemic disease further consideration
Class 4: severe systemic disease
Class 5: not likely to survive Class 5: do not proceed w/o w/o procedure anesthesia Preprocedural Evaluation
. Medical history . Previous adverse experience w/ sedation . Allergies . Current meds . NPO . Labs . Patient consent The Joint Commission
Requires history & physical documentation risks and options be discussed
Does NOT require a separate consent in addition to hospital consent
Pre-post procedural documentation w/ 48 hrs Equipment used during moderate sedation
• Intravenous access • Cardiac monitor • Automatic blood pressure cuff • Pulse oximeter • Oxygen source • Suction equipment • Code Cart should always be available ACR-SIR Procedure Monitoring Guidelines
. Intravenous access . Homeothermia should be preserved . Protected from pressure or position related injuries . Physiologic measurements every 5 mins level of consciousness respiratory rate pulse BP heart rate cardiac rhythm Procedure Documentation
Documentation, documentation, documentation Medication given, dose, route, time, response Depth of sedation: Ramsey Scale 0) none, patient is awake 1) Mild, occasionally drowsy 2) Moderate, frequently drowsy, easy to arouse 3) Severe, difficult to arouse “S” Sleeping Post-Sedation Care
Returned to baseline level of consciousness Vital signs are stable Sufficient time since reversal agent given OP discharged to a (responsible) adult Provided w/ written instructions (ASA does not dictate a specific scoring system but best known is Aldrete scoring) Medications
Lorazepam Indications
Contraindications
Dosing Guidelines
Naloxone Diazepam Contraindications/High Risk . Allergies to medication . Chronic Renal Failure . Currant medications . Chronic Liver Failure . Morbid Obesity . Elderly/Peds . COPD . Pregnancy . CAD Opioids Benzodiazepines
Used for pain control Used for sedative Morphine (morphine sulfate) Diazepam (valium) Fentanyl (fentanyl citrate) Midazolam (versed) Meperidine (Demerol) Lorazepam (Ativan) Opioids
• Most effective for relieving dull, tonic pain • Less effective for intermittent sharp pain • Causes mild sedation • Causes respiratory depression • Can nausea, vomiting • Does cross the placenta • Does NOT cause amnesia Benzodiazepines
. Sedation and hypnosis . Minimal respiratory depression . Decreased anxiety . Pronounced effect on . Increased muscle elderly/peds relaxation . Can cross the placenta . Antegrade amnesia and are excreted in . Anticonvulsant properties breast milk Opioids commonly used in moderate sedation
Brand Name onset duration dose
Morphine Less than Up to 4 hrs 2mg 10 mins Fentanyl 2 -3 mins 30 – 60 mins 25ug Causes less hypotension/ Cardiovascular depression Demerol 5 – 15 mins 2 – 4 hrs 10 -25mg Not used w/ hx cardiac disease Benzodiazepines commonly used in moderate sedation
Brand Name onset duration dose
Versed 1 – 3 mins 1 hr 1mg
Valium 2 – 3 mins Up to 6 hrs 1 – 2mg
Ativan 30 – 60 mins Can be long 2mg lasting Opioid overdose
Characterized by: decreased respiratory drive hypotension significant nausea/vomiting
Reversal agent
Narcan Narcan (Naloxone)
Can be inject:
IV 0.1mg – 0.3mg effective w/ 2 mins
IM 0.4mg effective w/ 5 mins
Nasal spray 4mg
Short duration of action (20-30 mins) may have to be repeated Benzodiazepine overdose
Characterized by: deep sedation deep respiratory depression decreased response to external stimuli
Reversal agent
Romazicon Romazicon (Flumazenil)
Injected IV series of small amounts 200 ug per 1 min up to 1mg
Short acting 30 – 60 mins resedation can occur if reinjection is necessary airway support should be considered Antibiotics bacterials fungals
Are anti-infective drugs that kill or stop the spread of an infectious agent Hypertension
1 out of 3 adults in America has high blood pressure Antihypertensive Meds
Calcium channel ACE inhibitor Beta blockers blockers
Most widely used Recommended for Promote lower heart considered “first line” pt under 55 or pt rate & reduce tremors treatment w/ ESRD
Ultimate goal is to lower blood pressure to prevent heart attack, stroke, heart failure Vasopressors: cause blood vessels to constrict which will
the flow of blood blood pressure
Epinephrine ACLS Vasopressin Vasodilators: cause widening of walls of blood vessels
blood flow blood pressure
Nitroglycerin (angina, acute coronary artery syndrome) Coagulation Modifiers
Act on blood coagulation pathway to either promote or prevent blood clot formation
Anticoagulants: prevents venous and arterial clot formation
Antiplatelet Agents: prevent arterial clot formation
Thrombolytics: dissolves blood clots
Hemostatics: promotes clot stability Fibrinolytic Drugs
Are used to break down/dissolve blood clots
Three most commonly used are:
tPA tissue plasminogen activator SK streptokinase UK urokinase Indications
Myocardial infarction Pulmonary embolus Acute ischemic stroke Deep vein thrombosis Ischemic limb injury Contraindications/side effects
Suspected hemorrhagic stroke Recent trauma Previous GI bleed Pregnancy Recent surgery Advance liver disease Gastrointestinal drugs Antiemetics: used to treat nausea/vomiting GERD: proton pump inhibitors GIST: Gleevec IBS: helps w/ diarrhea constipation IBD: Crohn: Cimzia UC: Asacol Anti-Inflammatory Drugs (OTC)
Nonsteroidal anti-inflammatory drugs Steroids (NSAIDs) (Corticosteroids)
Analgesics, antipyretic Reduce inflammation Anti-inflammatory suppress the immune system Aspirin, Ibuprofen Naproxen Orally, injected, Inhalers, topical Non-narcotic/non-addictive Acetaminophen NSAIDs (Tylenol) (Aspirin)
Analgesic Analgesic Antipyretic Antipyretic Does NOT reduce Anti-inflammatory inflammation generally slightly more generally a little safer effective should only be used for short period of time Adverse effects/risks
NSAIDs: GI upset (n/v/d/c) severe cases ulcer/bleed Acetaminophens: liver damage Corticosteroids: a lot depends on how you are using them Responding to adverse/allergic reaction to contrast
BEST Response
Be cautious and pre medicate Two frequently used regiments recommended by ACR
1) Prednisone – 50 mg po @ 13 hrs, 7 hrs and 1 hr before contrast inj, plus 50 mg Benadryl (IV, IM, PO) 1 hr prior 2) Medrol – 32 mg PO 12 hrs and 2 hrs prior to inj plus 50 mg Benadryl 1 hr prior Greatest effect on pt’s w/ previous mild/moderate contrast reactions High risk patients
Any pt that has experienced an anaphylactic reaction in response to an allergy to anything
Prior contrast allergy Renal insufficiency Cardiac disease Asthma When assessing a patient for possible contrast reaction
. How does the patient look? . Can the patient speak? How does pt’s voice sound? . How is the pt’s breathing? . What is the pt’s pulse strength and rate? . What is the pt’s blood pressure? Moderate reactions requiring medical intervention
Allergic-like Physiologic
. Diffuse hives/itchy skin . Protracted . Diffuse erythema nausea/vomiting . Facial edema w/o . Hypertensive urgency dyspnea . Isolated chest pain . Throat . Vasovagal reaction tightness/hoarseness requires treatment w/o dyspnea . Wheezing/bronchospasm Severe reaction:
When any of the “moderate” reactions goes down hill quickly
“CALL A CODE” The worst response to “how are you feeling”
“I’m feeling a little funny/strange”
W/o any possible prediction or prior history of any reactions to meds or contrast these (few) pt’s fit into a category called
Idiosyncratic drug reactions What is contrast media?
It is a substance that is either radiolucent or radiopaque that is administered to increase
radiographic contrast in an organ Contrast enhanced exams
Why do we use contrast?
Contrast increases the native (existing contrast) of organs
It separates them from surrounding tissue
It provides information on size, shape and position of structures
It can increase or decrease the density of a structure What are the desirable features of a contrast agent
. Easy to administer . No toxicty/carcinogenicity . Stable compound . Concentrates in area of interest . Proper demonstration of the organ system . Should have rapid elimination . Minimal distress to patients . Cost effective All contrast media are not the same
Viscosity Osmolality Chemotoxicity LD50 (Lethal Dose given all at once which causes the death of 50% of a test group of animals) Two basic categories
Negative Positive
double contrast Negative contrast agents are gases of low density which appear radiolucent
air oxygen
Carbon dioxide CO2 Positive contrast has high atomic numbers and appears radiopaque on images
Water soluble Water insoluble
Iodinated contrast Barium sulfate
ionic Non ionic
HOCM LOCM Iso osmolar Ionic Non ionic HOCM LOCM
• High osmolality • Low osmolality • Associated w/ higher • Fewer side effects, incidence of adverse most are mild reaction • Approximately twice • Weaker ability to the osmolality of attenuate x-rays, human serum leading to higher • Usually more concentrations expensive Barium sulfate
. Has better coating properties than iodinated contrast . Can be ingested or rectally administered . Rare to have adverse reaction . NOT water soluble . NOT used for p/o pt’s . NOT used if question of GI perforation ( can be toxic if leaked into mediastinum or peritoneum) . Is inexpensive compared to Non ionic contrast Mri contrast agents
Gadolinium based compounds are the most commonly used
Currently there are 9 contrast agents approved in USA by FDA
Very well tolerated w/ very low incidence of adverse reaction Risk factors w/ GBCM
Pt w/ previous allergic-like reaction
Pt w/ acute or chronic renal insufficiency GFR < 30
Pt w/ asthma Contraindications for MRI
Pacemaker, defibrillator Metallic FB in the eye Deep brain stimulator Swan-Ganz catheter Cerebral aneurysm clips Cochlear implant Magnetic dental implants Drug infusion devices Bullet or gunshot pellets Basic Life Support
“Annie Annie are Assess the pt you OK” Call for help
C A B
Compressions Airway Breathing 2 rescue 30 compressions tilt chin breaths ACLS
Vent, Asystole/ Bradycardia Tachycardia Fib/Tach PEA
Epinephrine Epinephrine Atropine Adenosine vasopressin Vasopressin Epinephrine Beta-blockers
Amiodarone Dopamine Amiodarone
Lidocaine ACLS cont.
Acute Coronary Syndrome Acute stroke
Oxygen tPA
Aspirin
Nitroglycerin
Morphine
Fibrinolytic therapy
Heparin References:
American Journal of Roentgenology (AJR) American College of Radiology (ACR) American Society of Anesthesiologist (ASA) RadioGraphics RSNA