VABC Pharmacology & Infusion Therapy 1 — Questions and Answers
Question 1: Which IV solution is classified as isotonic and most closely matches the osmolarity of human blood?
- 0.45% Sodium Chloride
- 0.9% Sodium Chloride (Correct answer)
- 3% Sodium Chloride
- 10% Dextrose in Water (D10W)
Correct answer: 0.9% Sodium Chloride
0.9% Sodium Chloride (Normal Saline) is isotonic with an osmolarity of approximately 308 mOsm/L, matching plasma osmolarity.
Question 2: A patient receiving vesicant chemotherapy via peripheral IV develops swelling, blanching, and pain at the infusion site. This presentation is most consistent with:
- Phlebitis
- Infiltration
- Extravasation (Correct answer)
- Catheter-related bloodstream infection
Correct answer: Extravasation
Extravasation is the leakage of a vesicant solution into surrounding tissue, causing blanching, swelling, and pain that can progress to tissue necrosis.
Question 3: Which pharmacokinetic factors most significantly influence the rate of drug distribution to tissues after IV administration?
- Protein binding and lipid solubility (Correct answer)
- Oral bioavailability and first-pass metabolism
- Renal clearance and urine pH
- GI absorption and hepatic extraction ratio
Correct answer: Protein binding and lipid solubility
Protein binding limits free drug available for distribution, while lipid solubility determines how readily a drug crosses cell membranes into tissues.
Question 4: Total Parenteral Nutrition (TPN) formulations must be administered via which vascular access route due to their hyperosmolarity?
- Short peripheral catheter
- Midline catheter
- Central venous catheter (Correct answer)
- Subcutaneous infusion device
Correct answer: Central venous catheter
TPN osmolarity typically exceeds 900 mOsm/L, requiring central venous access to prevent chemical phlebitis and venous sclerosis of peripheral veins.
Question 5: Which of the following medications is classified as a vesicant?
- 0.9% Normal Saline
- Vancomycin
- Doxorubicin (Correct answer)
- Lactated Ringer's Solution
Correct answer: Doxorubicin
Doxorubicin is a vesicant chemotherapy agent capable of causing severe tissue necrosis upon extravasation; vancomycin is an irritant, not a vesicant.
Question 6: What is the primary purpose of adding heparin to a catheter lock solution in vascular access protocols?
- Prevent catheter-related infection
- Maintain catheter patency by inhibiting clot formation (Correct answer)
- Reduce phlebitis at the insertion site
- Neutralize residual medication in the lumen
Correct answer: Maintain catheter patency by inhibiting clot formation
Heparin lock solutions prevent thrombus formation within the catheter lumen, maintaining patency between infusions.
Question 7: According to INS Standards of Practice, solutions with an osmolarity exceeding which value require administration via a central venous access device?
- 500 mOsm/L
- 600 mOsm/L
- 800 mOsm/L
- 900 mOsm/L (Correct answer)
Correct answer: 900 mOsm/L
The INS recommends that solutions with osmolarity greater than 900 mOsm/L be administered via central venous access to prevent peripheral vein damage.
VABC Pharmacology & Infusion Therapy 1
Which IV solution is classified as isotonic and most closely matches the osmolarity of human blood?