Scaling the Heights of Flexible Learning: Anesthesia, Analgesics, Pharmacology, and Radiologic Contrast

Flashcards cover analgesia, anesthesia, sedation levels, anesthetic agents, pharmacologic drug classes, and iodinated contrast media with reactions, contraindications, and management.

What is an analgesic?

A drug that provides analgesia (pain relief) by acting on the peripheral and/or central nervous system; distinct from anesthetics.

How do analgesics differ from anesthetics?

Analgesics relieve pain; anesthetics temporarily depress neuronal function to produce loss of sensation (and sometimes unconsciousness).

What is an anesthetic agent?

An agent that reversibly depresses neuronal function, producing loss of sensation.

What is Local Anesthesia?

Numbs a small area of tissue for a minor procedure.

What is Regional Anesthesia?

Numbs a larger part of the body and does not usually render the person unconscious; may include sedation.

Give an example of Regional Anesthesia.

Spinal and epidural anesthesia are examples of regional anesthesia.

What is General Anesthesia?

Affects the entire body and makes the person unconscious; administered IV or by inhalation.

What characterizes mild sedation?

A patient responds normally to verbal commands; airway and ventilatory/cardiovascular functions are unaffected.

What characterizes moderate sedation?

The patient responds purposefully to verbal commands or light tactile stimulation; airway, ventilation, and cardiovascular functions are usually adequate.

What characterizes deep sedation?

Airway patency and spontaneous ventilation may be compromised, sometimes requiring maneuvers to relieve obstruction.

What are antihistamines used for and how do they work?

Antihistamines target histamine to relieve allergy symptoms (itching, sneezing, runny nose); best taken before reaction and can build up in blood to block histamine release.

What is histamine?

A chemical that transmits messages to the brain, triggers stomach acid release, and is released during immune responses to injury or allergy.

What are antianxiety (anxiolytic) drugs and give examples?

Drugs that calm the CNS to reduce anxiety; benzodiazepines like diazepam (Valium) and lorazepam (Ativan) used for anxiety, muscle spasms, and seizures; often used preoperatively in radiology.

What are antiarrhythmic drugs?

Medications that suppress abnormal heart rhythms (e.g., atrial fibrillation, atrial flutter, ventricular tachycardia, ventricular fibrillation).

What are antibacterial drugs used for in interventional radiology?

Antibiotics used prophylactically to prevent infection and reduce septicemia risk during catheter manipulations in infected spaces.

What are anticoagulants and why check coagulation status before IR procedures?

Agents that prevent blood coagulation; assessing coagulation parameters helps minimize bleeding risk and correct coagulopathy when needed.

What are antidepressants used for?

Treat clinical depression and other conditions such as OCD, generalized anxiety disorder, PTSD, and chronic pain.

What are antiemetic drugs?

Drugs effective against vomiting and nausea; used for motion sickness and side effects of opioids, general anesthetics, and chemotherapy.

What are antihypertensive drugs?

Drugs used to treat hypertension to prevent complications like stroke and myocardial infarction.

What are anti-inflammatory drugs?

Drugs that reduce inflammation by blocking substances that cause redness, swelling, and pain.

What is the difference between antiseptic and disinfectant?

Antiseptics are applied to the body; disinfectants are applied to nonliving surfaces.

What are bronchodilators?

Bronchodilators dilate bronchi/bronchioles to reduce airway resistance and increase airflow; can be endogenous or administered.

What are laxatives and cathartics?

Laxatives increase stool passage; cathartics are stronger and evacuate the entire colon.

What is antidiarrheal medication?

Drugs that slow gut movement to reduce diarrhea and make stools less watery.

What are diuretics and what do they do?

Diuretics promote diuresis by increasing sodium and water excretion, reducing blood volume and blood pressure.

What are sedatives?

Drugs that slow brain activity (calming or sleep-inducing); also known as tranquilizers or depressants.

What is meant by vasodilation and vasoconstriction?

Vasodilation widens blood vessels; vasoconstriction narrows them; both affect blood flow and pressure.

What is a contrast agent?

A substance placed in the body to increase image differentiation of structures on radiographs.

What is a negative contrast agent?

Allows X-rays to penetrate more easily; the structure becomes radiolucent/dark (e.g., air, oxygen, carbon dioxide).

What is a positive contrast agent?

Absorbs X-rays; the structure becomes radiopaque/white (e.g., iodinated contrast media, barium).

What is ionic (high-osmolar) contrast media (HOCM)?

Ionic contrast media that dissociate into ions; osmolality can be up to 5x serum; potentially toxic; used nonintravascularly (oral/rectal) as appropriate.

What is non-ionic (low-osmolar) contrast media (LOCM)?

Non-dissociating; osmolality about 2x serum; fewer side effects and less nephrotoxicity; examples include Ultravist and Omnipaque.

What is iso-osmolar contrast media?

Contrast media with osmolality approximately equal to serum; preferred in renal impairment; example Visipaque.

What are common brands of iodinated contrast agents and their generic names?

Ultravist (iopromide), Omnipaque (iohexol), Visipaque (iodixanol).

What factors contribute to discomfort, side effects, and reactions to iodinated contrast media?

Iodine concentration, viscosity, osmolality, miscibility, and toxicity.

What is viscosity in iodinated contrast agents?

Thickness or resistance to flow; affected by concentration and molecular size; lowering concentration reduces viscosity but may reduce opacification.

What is osmolality in contrast media?

Number of particles per kilogram of water; higher osmolality increases risk of adverse reactions; linked to concentration.

What is miscibility in contrast media?

Contrast agents should mix readily with blood.

What is toxicity in iodinated contrast media?

Higher concentration and ionic agents increase toxicity; viscosity can rise when cooled.

What are absolute contraindications to iodinated contrast media?

Documented previous severe reaction (anaphylaxis, angioedema, bronchospasm) to iodinated contrast.

What are relative contraindications to iodinated contrast media?

Milder previous reactions, renal impairment, or risk factors for allergic reaction to iodinated contrast media.

What is extravasation in the context of contrast administration?

Unintentional leakage of vesicant fluids or medications from a vein into surrounding tissue.

What are vasovagal reactions and how are they treated?

Reactions with bradycardia and hypotension; treat with leg elevation, Trendelenburg position, oxygen, atropine, and possibly epinephrine; rapid IV fluids and close vital signs monitoring.

What is contrast-induced nephrotoxicity?

In normal renal function, uncommon and LOCM vs HOCM shows no clear advantage; in renal impairment LOCM is less nephrotoxic; hydration reduces risk.

What cardiovascular toxicity can occur with iodinated contrast?

In patients with cardiac disease, risk of hypotension, tachycardia, arrhythmias; possible CHF, pulmonary edema, or cardiac arrest.

What neurotoxicity can iodinated contrast cause?

Effects on the blood-brain barrier due to hypertonicity; symptoms include headache, confusion, seizures, altered consciousness, visual disturbances.

How are contrast reactions categorized and treated?

Most reactions are mild and managed with observation; severe reactions require immediate treatment and often hospitalization; categories include mild, moderate, and severe with described signs.

What are delayed contrast reactions?

Reactions occurring 3 hours to 7 days after contrast administration; often not observed by radiologists due to early discharge.