Pharmacology and Equipment in Interventional Radiology

Pharmacology and Equipment in Interventional Radiology

RAT TEST - EQUIPMENT

• RAT Test Overview

  • Individual RATs with each question worth 4 marks.

  • Uncertainty allows for multiple answers. Marks assigned for correct answers.

• tRAT

  • Completed in groups with a common set of questions.

  • Marks are assigned based on ticks for correct answers (1 to 4 ticks correspond to 4, 3, 1, or 0 marks).

Learning Outcomes

• Comprehend the basic principles of pharmacology.

• Identify common drugs used in interventional radiology (IR) procedures.

• Highlight the radiographer's role in drug administration, monitoring, and patient care during IR.

• Discuss safety, legal, and ethical considerations in pharmacological practices.

• Link to module learning outcome: Demonstrate imaging techniques, patient radiation protection, and drug/contrast agent preparation.

Importance of Pharmacology

• Enhances procedural outcomes.

• Ensures patient comfort and safety.

• Supports minimally invasive techniques.

Role of Radiographers in Drug Administration

• Administer drugs under supervision.

• Monitor and identify adverse reactions.

• Ensure drug safety and maintenance of proper documentation.

Administration of Drugs

• Definition: Application of a drug to the body.

• Routes of Administration: Methods through which drugs are introduced into the body.

• Selection Considerations:

  • Physical characteristics of the drug.

  • Required speed of absorption.

  • Necessary concentration at specific body areas.

  • Patient condition and related factors.

Pharmacokinetics

• Involves the movement of drugs through absorption, distribution, metabolism, and elimination.

Absorption

• More common routes in IR are intravenous (IV) or intra-arterial (IA) for rapid action.

• Factors affecting absorption:

  • Blood flow at administration site.

  • Drug formulation.

Distribution

• Transports drugs from the bloodstream to tissues/organs. Influenced by:

  • Perfusion to target organs.

  • Plasma binding proteins.

  • Blood-brain barrier.

Metabolism

• Chemical modification of drugs for elimination, primarily via the liver.

• Enzyme activity and first pass effect are critical components.

Elimination

• The body removes drugs through:

  • Renal excretion.

  • Hepatic (liver) excretion.

  • Other pathways including sweat, lungs, saliva.

Pharmacodynamics

• Examines the biological effects of drugs, including mechanisms of action and dose-response relationships.

Mechanisms of Action

• Agonists: Activate receptors to produce a effect.

• Antagonists: Block the action of agonists.

• Enzyme Inhibitors: Interfere with enzyme action.

Dose-Response Relationships

• Therapeutic Effect: Desired outcome.

• Toxic Effect: Undesired harmful effects.

• Dose-Response Curve: Graphical representation of drug response over varying doses.

Factors Influencing Drug Efficacy

• Age, comorbidities, and drug interactions significantly impact outcomes.

Common Drug Categories in IR

• Contrast Agents:

  • Enhance imaging by highlighting blood vessels and structure functionality.

  • Types include iodinated contrast media, gadolinium-based agents, and barium sulfate.

  • Considerations: adverse reactions, warming of agents, and injection pressures.

• Anticoagulants and Antiplatelets:

  • Used to manage clotting, examples include heparin, warfarin, clopidogrel, and aspirin.

• Sedation:

  • Involves relaxation without pain relief, often paired with analgesics.

  • Drugs like midazolam are utilized for sedation in prolonged procedures.

• Analgesics:

  • Minimize pain during procedures often through intravenous administration.

  • Examples include lidocaine (local anesthetic) and fentanyl or morphine (analgesics).

Embolization

• Involves blocking abnormal blood vessels using materials like coils or glue.

• Clinical indications:

  • Control or prevent bleeding, manage uterine fibroids, occlude tumors, and treat AVMs.

  • Thrombolytics

• Thrombolytics: Dissolve abnormal clots (e.g., alteplase, Urokinase).

  • Essential for maintaining blood circulation and preventing tissue damage.

Vasodilators and Vasoconstrictors

• Control vascular tone for optimal imaging and treatment.

• Examples include nitroglycerin (vasodilator) and epinephrine (vasoconstrictor).

Antibiotics

• Prevent infections during high-risk IR procedures (e.g., cefazolin, vancomycin).

Safety, Legal, and Ethical Considerations

• Patient Monitoring: Focus on vital signs, including blood pressure, heart rate, and oxygen saturation.

• Adverse Reactions: Recognizing and managing mild to severe reactions associated with drug administration.

Legal Responsibilities of Radiographers

• Responsible for ensuring drugs are properly prescribed/administered under supervision, following protocols for drug storage and handling.

Ethical Considerations

• Need for informed consent regarding off-label drug use and clear communication about potential side effects to patients.

Management of Complications

• Bleeding: Monitor vital signs and assist in treatment.

• Allergic Reactions: Prompt recognition and management critical, including administration of epinephrine.

• Contrast Induced Nephropathy: Awareness of risk factors and preventative actions such as hydration and monitoring renal function.

Discussion Points

• Address challenges faced by radiographers in IR concerning pharmacology.

Case Study Example

• Discussion of a scenario involving angioplasty procedures and monitoring responses to sedation.

Conclusion

• Encouragement for questions and clarifications.