Vocabulary
Normal Saline (NS) – A sterile solution containing 0.9% table salt (sodium chloride) in water, used for dilution or intravenous administration.
Sterile Water (SW) – Purified sterile water used to prepare powdered medicines before direct administration.
Vial – A container in which the drug is placed in the form of a dry powder, ready for reconstitution.
Concentration or Final Concentration – The amount of drug dissolved in a liquid, expressed as milligrams per milliliter (mg/mL). This physical quantity shows the strength of the final solution.
Dilution – The process of adding liquid (most often normal salt) to achieve the required concentration of the drug for safe and effective administration.
Intramuscular (IM) – Method of drug administration in which the drug is injected directly into the muscle mass, allowing a slower and gradual release in the body.
Reconstitution Conversions
Preparation of medicines in the form of powder or concentrate is a standard procedure in the work of nurses. Reconstitution involves mixing the dry form of the drug with an exact amount of liquid, most often sterile water or saline, to obtain a solution that is ready for safe and effective administration to the patient.
Determine What Information is Needed From the Problem
You need to know:
Order
Final concentration
Dimensional Analysis Review
Using dimensional analysis, we can determine the amount of medicine in milliliters (mL) that should be given to the patient.
Rule 1. Define the problem and determine the units the final result should have.
or
Rule 2. Solve the problem step by step until the units on the left match the units on the right.
Rule 3. Make sure the units match EXACTLY
Rule 4. Multiply all the values in the numerator and write the result in the numerator, then multiply all the values in the denominator and write in the denominator.
Rule 5. Write the result to four decimal places, then round it off and add the appropriate units.
Conversion Steps
Reconstitution Example
Order: 300mg IM of a substance
Available: 1000mg vial with directions to add 4.6mL for injection (final concentration of 200mg/mL)
How many mL should you administer?
mL→x300mg = 1.5mL
