Wk 10: Administration of cancer treatment Flashcards
What are the advantages of injection?
- Bioavailability + predictable plasma levels
- Not affected by swallowing difficulties/vomiting
What are the disadvantages of injection?
- Risks associated w/ IV
- Drug/fluid incompatibilities
- IV access
- Inconvenient + time consuming
- Cost
What are the types of injections?
- Subcutaneous
- Intramuscular
- Intradermal
- Intravenous
What is a cannula?
- Short tube put into vein in lower arm/back of hand
- Clear dressing on top
- Short term
Why are central lines preferred over cannulas?
- Temperamental + patient can readily move arm
- Speed of admin = harder to control
- Fragile veins
- High risk of extravasation
What is a central venous catheter?
- Tube inserted into vein (subclavian, femoral or jugular)
- Catheter pushed along vein til reaches larger vein (vena cava)
- Secured w/ 2 stitches
- Long term
What is a peripherally inserted central catheter (PICC)?
- Tube inserted into vein in arm
- Catheter pushed along vein til reaches larger vein (vena cava)
What is a portacath?
- Long term CVC w/ no external parts
- Catheter in subclavian, end attached to titanium/plastic port planted in subcutaneous tissue in chest
- Thick rubber septum covers port, once sutured, port is enclosed
- Needle inserted through skin + rubber septum
What are the different types of intravenous administration methods?
- Continuous infusion
- Intermittent infusion
- Direct intermittent injection
What is continuous infusion?
Med delivered at constant rate over prescribed time period
What is intermittent infusion?
Small vol (25-250ml) given over shorter period of time (15mins-2hr)
What is direct intermittent injection?
Bolus injection of drug straight to vein
Outline the issues of central venous catheters
- Infection
- Blood clots
- Blockage
How does an infection present in CVC + how is it treated?
- Swelling, redness, discharge at exit site
- Treat: antibiotics or remove line
How do blood clots present in CVC + how is it treated?
- Swelling, redness, tenderness in arm, chest + neck.
- SOB + tightness
- Treat: thrombolytic med or line removed
How is a blockage treated in a CVC?
- Flushed w/ saline
- If blocked w/ blood: thrombolytic flush out
What is extravasation?
- Accidental leakage of chemotherapy from vein into surrounding tissue
- Esp. vesicant drugs
What are the symptoms of extravasation?
- Redness
- Swelling
- Burning
- Superficial skin loss
- Tissue necorisis
What are the risk factors of extravasation?
- Fragile vein
- V young/old
- Confused/sedated patient not reporting discomfort
- Concurrent med: analgesic, anticoag, vasodilators + diuretics
- Peripheral admin
- Inexperienced staff
- Bolus injections
How do you treat/manage extravasation?
- Discontinue infusion + aspirate residual drug from cannula
- Refer to hematologist/oncologist/plastics
- Infusion of antidote (dexrazoxane w/ anthracycline)
What are the advantages of oral therapy?
- More convenient
- Less expensive
- Lower toxicity
- Avoid complications associated w/ IV access
What are the disadvantages of oral therapy?
- Adherence
- Variable plasma pharmacokinetics
- Manage drug interactions
- Nausea + vom
Give examples of less common routes of admin
- Intrathecal: fluid into spine + brain (brain tumours, leukaemia + lymphoma)
- Intracavitary (bladder, abdomen + chest cavity)
- Intralesional/tumoral (into tumour)
- Topical (skin cancer - 5 FU cream)
