1. IV Medication and Titration Calculations
Chapter 18
IV Medication and Titration Calculations

2. Titration
Adjustment of dosage within specific range to obtain desirable measurable physiologic response

3. Titrated Medications
Many IV medications used in critical care and life-threatening situations to alter or maintain vital physiologic functions
Medications requiring titration have very rapid action, short duration, and narrow margin of safety
Require continuous monitoring

4. Titrated Medications Dosages calculated to nearest tenth
Flow rates rounded to nearest mL
Although some electronic infusion devices (EIDs) can administer medication flow rate to tenth of a mL

5. Titrated Medications May be prescribed by either: Dosage Body weight
mcg/mg/units per min/hr
Body weight
mcg/mg/units per kg per min/hr

6. Titrated Medications
May be prescribed to infuse within specific range, such as 1 to 3 mcg/min, to achieve specific physiologic response
e.g., maintaining systolic blood pressure (BP) greater than 100 millimeters of mercury (mm Hg)

7. Titrated Medications Usually infused using EID
e.g., volumetric or syringe pump
Display dosage and flow rates
Can be set to deliver fractional dosages

8. Titrating Using gtt/min
Method not recommended
If EID or syringe pump not available, use microdrip tubing (60 gtt/mL)
Remember:
Rate in gtt/min when using microdrip tubing same as mL/hr

9. Titrating IV Infusion EIDs used for administration
Flow rates calculated in mL/hr for lowest and highest dosage prescribed and adjusted within this range to elicit desired physiologic response

10. Example 1
Cardiac medication with strength of 125 mg/100 mL to infuse at rate of 20 mg/hr
Calculate mL/hr flow rate

11. Example 1
= 16 mL/hr

12. Example 2 Dosage of 2 mcg/min prescribed using 8 mg in 250 mL solution
Calculate mL/hr flow rate

13. Example 2
= 3.75, or 4 mL/hr

14. Example 3
Medication prescribed at rate of 3 mcg/kg/min for adult weighing 95.9 kg
Solution strength 400 mg in 250 mL
Calculate mL/hr flow rate

15. Example 3
Calculate 3 mcg/min dosage for 95.9 kg

16. Example 3 Using Two-Step Method
Calculate mL/hr flow rate for mcg/min
= 10.79, or 11 mL/hr

17. Example 3 Using One-Step Method
First two ratios are same as two-step method
mL mL mg hr mg mcg

18. Example 3 Using One-Step Method
Match mcg denominator, which is provided by 3 mcg/kg/min dosage
Enter 3 mcg as numerator
mL mL mg mcg hr mg mcg kg/min

19. Example 3 Using One-Step Method
Both kg and min must be matched in next numerators
Either can be entered first, but min is best choice because conversion ratio is needed to change min to hr
Enter 60-min-equals-1-hr conversion
mL mL mg mcg min hr mg mcg kg/min hr

20. Example 3 Using One-Step Method
Enter 95.9 kg body weight as final numerator
mL mL mg mcg min kg
hr mg mcg kg/min hr

21. Example 3 Using One-Step Method
After cancelling alternate denominator/ numerator measures, only mL and hr remain
Complete the math
mL mL mg mcg min kg
hr mg mcg kg/min hr
= = 11 mL/hr

22. Example 4 Titrating IV infusion Dosage of 2 to 4 mcg/min prescribed
Solution being titrated has 8 mg in 250 mL
Calculate flow rate of medication for 2 to 4 mcg range

23. Example 4 Using Two-Step Method
= 3.75, or 4 mL/hr

24. Example 4 Using One-Step Method
= 3.75 or 4 mL/hr

25. Example 4
Since upper dosage range flow rate is twice that of lower dosage range flow rate (4 mL/hr), multiply by two
Flow rate range is 4 to 8 mL/hr