Volume Calculation for 50mg/mL Solution
To obtain 13mg from a 50mg/mL solution, you need to administer 0.26 mL.
Calculation Method
The calculation follows the basic formula for drug concentration:
Volume (mL) = Desired Dose (mg) ÷ Concentration (mg/mL)
- Desired dose: 13 mg
- Concentration: 50 mg/mL
- Volume needed: 13 mg ÷ 50 mg/mL = 0.26 mL
Critical Safety Considerations
Volumes less than 0.1 mL pose significant measurement accuracy challenges. While 0.26 mL exceeds this threshold, awareness of measurement limitations is essential for safe medication administration.
Measurement Accuracy Issues
- Current medical equipment does not permit accurate measurement of volumes less than 0.1 mL 1
- In pediatric intensive care settings, 7.4% of intravenous doses required preparation from less than 0.1 mL of stock solution, representing a substantial source of dosing error 1
- For 28.5% of pediatric ICU admissions, at least one dose was prepared from a volume less than 0.1 mL 1
Practical Administration Guidance
- Use a 1-mL syringe for accurate measurement of 0.26 mL, as this provides the precision needed for volumes in this range
- Ensure the syringe is calibrated in 0.01 mL increments for optimal accuracy
- Always use metric units (mL) exclusively when measuring and documenting medication doses to eliminate confusion and reduce error risk 2
- Avoid household measurement units (teaspoons, tablespoons) which significantly increase the likelihood of dosing errors 2
Common Pitfalls to Avoid
- Decimal point errors: When working with decimal values, incorrect decimal placement can result in ten-fold dosing errors 3
- Multiple unit confusion: Using different volumetric units (mL, cc, tsp) and their various abbreviations increases error likelihood 2
- Inadequate measurement devices: Using devices not calibrated for the required volume increases dosing variability 2