Dosage/Calc

An infant weighs 4 kg. What is the required amount of fluid per day in mL?

0-10 kg : 100 mL per kg 4 kg x 100 mL/kg = 400 mL

Calculate the amount of sodium chloride in 2000 mL NS. Recall NS is 0.9% NaCl (sodium chloride) Concentration %/100 x Volume (mL) = Y (Dosage Amount in g)

0.9%/100 x2000 mL = 18 g

Ordered 1000 mL D5W IV to infuse in 10 hours by infusion pump. Volume (mL)/Time (hr) = Y (Flow Rate in mL/hr)

1000 mL/10 hr = 100 mL/hr

Give patient 500 mg of dopamine in 250 mL of D5W to infuse at20 mg/hr. Calculate the flow rate in mL/hr. Ordered Per Hour/Have x Volume (mL) = Y (Flow Rate in mL/hr)

20 mg/hr / 500 mg x 250 mL = 10 mL/hr

Calculate the IV flow rate for 200 mL of 0.9% NaCl IV over 120 minutes. Infusion set has drop factor of 20 gtts/mL. Volume (mL)/Time (min) x Drop Factor (gtts/mL) = Y (Flow Rate in gtts/min)

200 mL/120 min x 20 gtts/mL = 33 gtts/min

Metroprolol (Lopressor), 25 mg PO, is ordered. Metropolol is available as 50 mg tablets. How many tablets would the nurse administer? Ordered/Have = Y (Tablets Required)

25/50 = 0.5

Ordered Lasix 40 mg IV push now. Available: 80 mg in 1 mL. How much will the nurse draw up?

40 mg/80 mg x 1 mL = 0.5 mL

Potassium chloride is available as 10 mg per tablet. Potassium Chloride (K-Dur), 40 mg, is ordered. How many tablets would the nurse administer? Ordered/Have = Y (Tablets Required)

40/10 = 4

Calculate the amount of dextrose in 1000 mL D5W. Concentration %/100 x Volume (mL) = Y (Dosage Amount in g)

5%/100 x 1000 mL = 50 g

Phenytoin (Dilantin), 0.1 g PO, is ordered to be given through a nasogastric tube. Phenytoin is available as 30 mg / 5 mL. How much would the nurse administer?

Convert 0.1 g to mg. mcg ← mg ← g ← kg ( x by 1,000 ) 0.1 g x 1,000 = 100 mg 100 mg30 mg x 5 mL = 16.7 mL

Infuse 250 mL over the next 120 minutes by infusion pump. Volume (mL)/Time (hr) = Y (Flow Rate in mL/hr)

Convert 120 minutes to hours. min → hr ( ÷ by 60 ) 120 min ÷ 60 = 2 hr 250 mL/2 hr = 125 mL/hr

An infant weighs 30.8 lb. What is the required IV flow rate in mL/hr to maintain proper fluid levels?

Convert 30.8 lb to kg. lb → kg ( ÷ by 2.2 ) 30.8 lb ÷ 2.2 = 14 kg 10-20 kg : 1,000 mL + 50 mL per each kg above 10kg 14 kg - 10 kg = 4 kg (There are 4 kg over 10 kg). 1,000 mL + (50 mL/kg x 4 kg) = 1,200 mL/day This is now an ordinary IV Flow Rate - mL Rate Question. The required volume is 1,200 mL and the time is one day. Volume (mL)/Time (hr) = Y (Flow Rate in mL/hr) There are 24 hours in one day. 1 day x 24 = 24 hr 1,200 mL/24 hr = 50 mL/hr

Calculate the IV flow rate for 1200 mL of NS to be infused in 6 hours. The infusion set is calibrated for a drop factor of 15 gtts/mL. Volume (mL)/Time (min) x Drop Factor (gtts/mL) = Y (Flow Rate in gtts/min)

Convert 6 hours to minutes. min ← hr ( x by 60 ) 6 hr x 60 = 360 min 1200 mL/360 min x 15 gtts/mL = 50 gtts/min

D

Dextrose

RL or LR

Lactated Ringer's

Flow Rate

Measure of the flow of liquid from an IV. Usually measured in gtts/minute (how many drops are released every minute) or in mL/hour (how many mL flow through each hour). gtts/minute is used for manually regulating an IV while mL/hour is used when utilizing an electronic IV regulator.

NS

Normal saline 0.9%

Drop Factor

Number of drops per volume of IV fluid. Varies depending on the tubing used. Usually measured in gtts/mL.

Mass for Mass Formula

Ordered/Have

Mass/Liquid for Liquid

Ordered/Have x Volume Per Have = Y (Liquid Required)

S

Saline

Aggrastat at 12.5 mg in 250 mL is prescribed to be infused at a rate of 6 mcg/kg/hr in a patient who weighs 100 kg. At what flow rate in mL/hr will you set the pump? Ordered Per Hour/Have x Volume (mL) = Y (Flow Rate in mL/hr)

The first step is to convert the order per time to the amount required for this particular patient. This is a Dosage By Weight Question. 100 kg is the weight in kg and 6 mcg/kg/hr is a dosage in terms of kg. Weight in Kg * Dosage Per Kg = Y (Required Dosage) 100 kg * 6 mcg/kg/hr = 600 mcg/hr Convert 600 mcg/hr to mg/hr. mcg → mg → g → kg ( ÷ by 1,000 ) 600 ÷ 1,000 = 0.6 mg/hr 0.6 mg/hr / 12.5 mg x250 mL = 12 mL/hr

W

Water

Solumedrol 1.5 mg/kg is ordered for a child weighing 74.8 lb. Solumedrol is available as 125 mg / 2mL. How many mL must the nurse administer?

Weight in Kg * Dosage Per Kg = Y (Required Dosage) Convert 74.8 lb to kg. lb → kg ( ÷ by 2.2 ) 74.8 lb ÷ 2.2 = 34 kg 34 kg * 1.5 mg/kg = 51 mg This is now an ordinary Mass/Liquid For Liquid Question. 51 mg is ordered and the medication is available as 125 mg / 2 mL. Ordered/Have x Volume Per Have = Y (Liquid Required) 51 mg/125 mg x 2 mL = 0.82 mL

A doctor orders 200 mg of Rocephin to be taken by a 15.4 lbinfant every 8 hours. The medication label shows that 75-150 mg/kg per day is the appropriate dosage range. Is this doctor's order within the desired range?

Weight in Kg x Dosage Per Kg = Y (Required Dosage) Convert 15.4 lb to kg. lb → kg ( ÷ by 2.2 ) 15.4 lb ÷ 2.2 = 7 kg 7 kg x 75 mg/kg = 525 mg (Minimum Desired Dosage) 7 kg x 150 mg/kg = 1,050 mg (Maximum Desired Dosage) 24 hours in one day and the medication is ordered every 8 hours. 24 hrs / 8 hrs = 3 times per day doctor ordered medication 200 x 3 = 600 mg ordered per day 600 mg is within the desired range of 525-1,050 mg Yes - doctor has ordered a dosage within the desired range.

gtts

drops