Sterile Preparations and Aseptic Technique Flashcards

When preparing a sterile IV admixture in a Laminar Airflow Workbench (LAFW), in which direction should the pharmacist work relative to the HEPA filter to maintain sterility?

Answer: Directly in front of the HEPA filter, working within the first-air zone closest to the filter

In a LAFW, HEPA-filtered 'first air' flows horizontally from the filter toward the operator. Critical sites (needle hubs, vial stoppers) must be placed in the direct airflow path from the filter — within the 'first-air zone' — to ensure sterile air bathes the product before it reaches human hands or room air.

According to standards for sterile compounding, what is the maximum Beyond-Use Date (BUD) for a low-risk sterile preparation stored at controlled room temperature?

Answer: 48 hours

Under USP -aligned Canadian pharmacy standards, low-risk sterile preparations (simple transfers from commercial sterile containers in ISO Class 5) have a maximum BUD of 48 hours at controlled room temperature, 14 days refrigerated, or 45 days frozen.

A pharmacist notices that the ISO Class 5 laminar airflow workbench has not been cleaned before beginning IV preparation. What is the correct cleaning sequence?

Answer: Sterile water wipe first, followed by 70% IPA wipe from back to front, starting from the HEPA filter and working toward the operator

The LAFW should be cleaned with a sterile water wipe first (to remove residue), followed by 70% IPA from back to front (HEPA filter side toward the operator) using overlapping strokes. Cleaning back-to-front pushes contaminants outward and away from the sterile field.

Which of the following is classified as a High-Alert Medication (HAM) by ISMP Canada that requires extra precautions when compounding sterile preparations?

Answer: Concentrated potassium chloride (KCl) injection

ISMP Canada classifies concentrated electrolytes, including concentrated potassium chloride (KCl) injection, as High-Alert Medications because they can cause fatal cardiac arrhythmias if administered undiluted or at incorrect concentrations. They require special storage, labelling, and double-checking protocols.

When reconstituting a powdered antibiotic for IV infusion, a pharmacist adds diluent to a vial using positive-pressure technique. What problem can result from excessive positive pressure in the vial?

Answer: Aerosolization or spray of drug content when the needle is withdrawn, creating a contamination and exposure risk

Excessive positive pressure in a vial during reconstitution can cause the contents to spray or aerosolize when the needle is withdrawn, creating both a contamination hazard to the sterile field and a potential exposure risk to the compounder. Pressure should be equalized or slight negative pressure maintained.

A hospital pharmacist is preparing a batch of total parenteral nutrition (TPN) admixtures. Which component sequence must be followed when mixing TPN to prevent precipitation?

Answer: Add calcium and phosphate sequentially with adequate dilution between them; never add them together concentrated

Calcium-phosphate precipitation is a major safety risk in TPN. Calcium and phosphate must be added separately with adequate dilution (using amino acid or dextrose as buffer between additions) and never in concentrated sequence. A precipitate can cause fatal pulmonary emboli if infused.