IV Calculations Heparin Insulin other meds Chapter 17

IV Calculations Heparin, Insulin & other meds Chapter 17

Concentration Definition Ø Concentration = Total Amount of Drug Total Volume (m. L) Ø Weight over volume: W V

Problem • An order is written for 25, 000 units of heparin in 250 ml of D 5 W to infuse at 1000 units/hr, what is the correct rate of the infusion (in ml/hr)? • Concentration of IV = 25, 000 units of heparin 250 m. L D 5 W • Concentration of IV = 100 units of heparin/m. L

Continued • IV rate = Dose desired Concentration of IV • IV rate = 1000 units/hr 100 units/m. L • IV rate = 10 m. L/hr

Problem • Heparin sodium 25, 000 units in 500 ml D 5 W and infuse at 2000 units/hr. How many m. L/hr will the pump be set ? • What is the concentration? 25, 000 units 500 m. L • 50 units/m. L • What is the flow rate: 2000 units/h 50 units/m. L • 40 m. L/h

Problem • Mr. Collins has an order for 800 units of heparin sodium per hour. Premixed 1000 ml bags containing 50, 000 units of heparin are available in the pharmacy stock area. • At what rate will the nurse set the infusion pump to deliver the dosage? Ø 16 m. L/h (concentration is 50 units/m. L) • Mr. Collins' heparin dosage needs to be changed to 750 units/hr. At what rate will the nurse set the infusion pump? Ø 15 m. L/h

Insulin • Doctor's order: Regular insulin 7 units/hr IV • Available: Regular insulin 50 units in 250 m. L NS • The concentration is ______ Ø 0. 2 units/m. L • The IV flow rate to deliver this dosage is: Ø 35 m. L/h

Insulin • Doctor's order: Regular insulin 12 units/hr IV • Available: Regular insulin 50 units in 100 m. L NS • The concentration is _____ Ø 0. 5 units/m. L • The IV flow rate to deliver this dosage is: Ø 24 m. L/h

Potassium Chloride • Order: KCl 40 m. Eq/L D 5 W to infuse at 2 m. Eq/h • What is the concentration? ______ Ø 40 m. Eq/1000 m. L = 0. 04 m. Eq/m. L • Rate for infusion pump: _______ Ø 50 m. L/h______

Magnesium Sulfate • Order: magnesium sulfate 4 g IV in 500 m. L D 5 W at 500 mg/h on an infusion pump • What is the concentration? ___ Ø 8 mg/ml_______ • Rate for infusion pump: ______ Ø 62. 5 m. L/h

Dosage Calculation: Lidocaine IVP • Order: lidocaine 100 mg IVP • Available: 2% lidocaine What is the concentration? _____ mg/m. L Ø 20 mg/ml How many milliliters will you administer? Ø 5 m. L

Finding Units/h from m. L/h • Concentration: 25, 000 units heparin/250 m. L D 5 W (100 units/m. L) • IV rate: 10 m. L/hr • How many units/h is the patient receiving? • Set up: 10 m. L/hr x 100 units/m. L = 1000 units/h

Finding Units/h from m. L/h • Supply: 25, 000 units heparin/250 m. L D 5 W • Concentration: 100 units/m. L • IV rate: 14 m. L/hr • How many units/h is the patient receiving? • Set up: 14 m. L/hr x 100 units/m. L Ø 1400 units/h

m. L/min to m. L/h Round m. L/min: <1 hundredths, >1 tenths BEFORE x 60 min/h! • Order: lidocaine 2 g in 250 m. L D 5 W IV to infuse at 5 mg/min. • What is the concentration? _____ Ø 2 g = 2000 mg = 8 mg/m. L 250 m. L • What is the flow rate for the infusion pump? ____________ • 5 mg/min = 0. 625 = 0. 63 m. L/min x 60 min/hr = 8 mg/m. L 37. 8 m. L/h

• Problem: Infuse lidocaine 1 g in D 5 W 200 m. L at 12 mg/min. • Find the concentration: 1 g = 1000 mg = 5 mg/m. L 200 m. L • What is the flow rate for the infusion pump? ____________ • 12 mg/min = 2. 4 m. L/min x 60 min/hr =144 m. L/h 5 mg/m. L

Concentration and Volume per Hour and Minute with a Drug in Micrograms • Problem: Infuse dobutamine 250 mg in D 5 W 500 m. L at 650 mcg/min. What is the flow rate in m. L/h for the infusion pump? • Find concentration: • 250 mg = 250, 000 mcg = 500 mcg/m. L 500 m. L • What is the flow rate for the infusion pump? ____________ • 650 mcg/min = 1. 3 m. L/min x 60 min/hr = 78 m. L/h 500 mcg/m. L

IV Medication Ordered per Kilogram per Minute • Order dopamine 750 mg in 500 m. L NS IV to infuse at 15 mcg/kg/min; weight 75 kg • Find concentration: • 750 mg = 750, 000 mcg = 1500 mcg/m. L 500 m. L • What is the order for how much the patient will receive per min? • 15 mcg/kg/min x 75 kg = 1125 mcg/min • What is the flow rate for the infusion pump? ____________ • 1125 mcg/min = 0. 75 m. L/min x 60 min/hr = 45 m. L/h • 1500 mcg/m. L