Heparin, Insulin & other meds IV Calculations Heparin, Insulin & other meds Chapter 17

Concentration Definition Concentration = Total Amount of Drug Total Volume (mL) Weight over volume: W V

Problem An order is written for 25,000 units of heparin in 250 ml of D5W 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 mL D5W Concentration of IV = 100 units of heparin/mL

Continued IV rate = Dose desired Concentration of IV IV rate = 1000 units/hr 100 units/mL IV rate = 10 mL/hr

Problem Heparin sodium 25,000 units in 500 ml D5W and infuse at 2000 units/hr. How many mL/hr will the pump be set ? What is the concentration? 25,000 units 500 mL 50 units/mL What is the flow rate: 2000 units/h 40mL/h

Problem Mr. Collins has an order for 800 units of heparin sodium per hour. Premixed 1000ml 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? 16 mL/h (concentration is 50 units/mL) Mr. Collins' heparin dosage needs to be changed to 750 units/hr. At what rate will the nurse set the infusion pump? 15 mL/h

Insulin Doctor's order: Regular insulin 7 units/hr IV Available: Regular insulin 50 units in 250 mL NS The concentration is ______ 0.2 units/mL The IV flow rate to deliver this dosage is: 35 mL/h

Insulin Doctor's order: Regular insulin 12 units/hr IV Available: Regular insulin 50 units in 100 mL NS The concentration is _________ 0.5 units/mL The IV flow rate to deliver this dosage is: 24 mL/h

Potassium Chloride Order: KCl 40 mEq/L D5W to infuse at 2 mEq/h What is the concentration? ______ 40 mEq/1000 mL = 0.04 mEq/mL Rate for infusion pump: _______ 50 mL/h______

Magnesium Sulfate Order: magnesium sulfate 4 g IV in 500 mL D5W at 500 mg/h on an infusion pump What is the concentration? ___ 8 mg/ml_______ Rate for infusion pump: ______ 62.5 mL/h

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

Finding Units/h from mL/h Concentration: 25,000 units heparin/250 mL D5W (100 units/mL) IV rate: 10 mL/hr How many units/h is the patient receiving? Set up: 10 mL/hr x 100 units/mL = 1000 units/h

Finding Units/h from mL/h Supply: 25,000 units heparin/250 mL D5W Concentration:100 units/mL IV rate: 14 mL/hr How many units/h is the patient receiving? Set up: 14 mL/hr x 100 units/mL 1400 units/h

mL/min to mL/h Round mL/min: <1 hundredths, >1 tenths BEFORE x 60 min/h! Order: lidocaine 2 g in 250 mL D5W IV to infuse at 5 mg/min. What is the concentration? __________  2 g = 2000 mg = 8 mg/mL 250 mL What is the flow rate for the infusion pump? ________________________ 5 mg/min = 0.625 = 0.63 mL/min x 60 min/hr = 8 mg/mL 37.8 mL/h

Problem: Infuse lidocaine 1 g in D5W 200 mL at 12 mg/min. Find the concentration: 1g = 1000 mg = 5 mg/mL 200 mL What is the flow rate for the infusion pump? ________________________ 12 mg/min = 2.4 mL/min x 60 min/hr =144 mL/h 5 mg/mL

Concentration and Volume per Hour and Minute with a Drug in Micrograms Problem: Infuse dobutamine 250 mg in D5W 500 mL at 650 mcg/min. What is the flow rate in mL/h for the infusion pump? Find concentration: 250 mg = 250,000 mcg = 500 mcg/mL 500 mL What is the flow rate for the infusion pump? ________________________ 650 mcg/min = 1.3 mL/min x 60 min/hr = 78 mL/h 500 mcg/mL

IV Medication Ordered per Kilogram per Minute Order dopamine 750 mg in 500 mL NS IV to infuse at 15 mcg/kg/min; weight 75 kg Find concentration: 750 mg = 750,000 mcg = 1500 mcg/mL 500 mL 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 mL/min x 60 min/hr = 45 mL/h 1500 mcg/mL