Titrations

Introduction to IV Medications and Titrations

• Discussion on IV medications previously.
• Confirmation of student proficiency in IV calculations.
• Transition into titration calculations.

Titration Overview

• Titration Definition:

  • Adjusting the dosage of medications according to patient needs.
  • Significant in emergencies or critical care for medications affecting heart rate, blood pressure, and cardiac output.

• Importance of Accuracy:

  • Medications have a narrow margin of safety.
  • Example Dosing:
  • medications may be ordered in:
    • milligrams per minute
    • milligrams per kilogram per minute
    • micrograms per kilogram per hour.

Practical Calculations

Example 1: Medication Ordered

• Medication ordered: 20 milligrams per hour.
• Concentration of medication: 125 milligrams per 100 milliliters.

Calculation Steps:

1. Start with question mark milliliters per hour.

2. Identify the order: 20 mg/hour.

3. Set up conversion:

   • Label:
     ext{mg (top) --> mg (bottom)}
   • Concentration:
     • 125 mg in 100 mL.

4. Calculation:

   • 20 imes rac{100}{125} = 16 mL/hour.

Example 2: Microgram Calculation

• Medication ordered: 2 micrograms per minute.
• Available: 8 milligrams per liter.

Calculation Steps:

1. Start with 2 micrograms/minute.
2. Convert units:
   • 1 milligram = 1000 micrograms.
3. Work with available medication:
   • Convert to mL/hour using the concentration.
4. Convert micrograms to milligrams:
   • Use conversions for hours if necessary.
5. Result: 3.75; rounded to 3.8 mL/hour as stated during lectures.

More Complex Dosing with Weight Involved

Example 3: Weight and Dosage Calculation

• Ordered dosage: 3 micrograms per kilogram per minute.
• Patient weight: 95.9 kilograms.

Calculation Steps:

1. Calculate micrograms per minute:
   95.9 kg * 3 micrograms = 287.7 micrograms/minute.
2. Convert to mL/hour for administration.
3. Repeat process to eliminate kilograms from calculations.
4. Units for mL/hour established.

Example 4: Adjusting Infusion Rate

• Dopamine ordered: 4 micrograms per kilogram per minute.
• Patient weight: 850 kilograms.
• Available medication: 200 milligrams per 250 milliliters.

Calculation Steps:

1. Eliminate kilograms:
   • 4 * 850 = 3400 micrograms/minute.
2. Convert units accordingly to mL/hour.
3. Set up and solve for calculation steps:
   • rac{3400}{1000} and transform it according to milliliters per hour with the context of the solution available.
4. Resulting answer reached: 15.

Range Medication and Dosage Adjustment

Worked Example with Range

• Medication ordered: ranging from 2 to 10 micrograms per hour.
• Calculate both lower and upper dosage limits.

Calculation Steps:

• For lower range: 2 micrograms/minute.
• For upper range: 4 micrograms/minute.
• Calculate each to milliliters per hour based on available rates.
  • Remember to state both results with a range (2.8 to 4.8). Confirm the written format for tests indicates a dash (3.8-7.5).

Heparin Calculation

Overview of Heparin as an Anticoagulant

• Administered as milliliters per hour or units per hour.
• Heparin does not require unit conversion at baseline.
• Initial calculation begins with 1000 units/hour.

Calculation Steps:

1. Start calculation basing units directly on supplied concentrations.
2. Use the given concentrations (e.g., 20,000 units in 500 mL).
3. Calculate total mL required leading to a result of 25.

Conclusion

Future Test Prepare

• The upcoming test will assess both titration and respiratory adjustments with respect to dosing and IV medication.
• Important items to note:
  • Look for directives on rounding answers.
  • Focus on practicing problems from both titration and IV medication to ensure comprehension and accuracy in calculations.

Additional Learning Notes

• Always remember to maintain labeling clarity during calculations to avoid confusion.
• Test preparation will include similar format and examples discussed; practice recommended to solidify skills and understanding.