Dosage Calculation of Critical Care Medications: mg/min Dimensional Analysis Method

mg/min to mL/h Scenario: Lidocaine 1 g has been added to 500 mL of D5W. The order states to infuse the lidocaine at 2 mg/min. The nurse needs to calculate the rate, in milliliters per hour (mL/h), at which to set the IV pump. Question: How does the nurse convert the ordered dose of 2 mg/min to mL/h?

mg/min to mL/h x mL = h

mg/min to mL/h x mL = 500 mL h 1 g

mg/min to mL/h x mL = 500 mL x 1 g h 1 g 1000 mg

mg/min to mL/h x mL = 500 mL x 1 g x 2 mg h 1 g 1000 mg 1 min

mg/min to mL/h x mL = 500 mL x 1 g x 2 mg x 60 min h 1 g 1000 mg 1 min 1 h

mg/min to mL/h x mL = 500 mL x 1 g x 2 mg x 60 min h 1 g 1000 mg 1 min 1 h

mg/min to mL/h x mL = 500 mL x 1 x 2 x 60 h 1 1000 1 1 h

mg/min to mL/h x mL = 500 mL x 1 x 2 x 60 = 60 mL/h h 1 1000 1 1 h

mg/min to mL/h So, Lidocaine infusing at 60 mL/h delivers 2 mg/min with a concentration of 1 g lidocaine/500 mL.

mg/min Feel free to contact your instructor for any questions or concern you may have.