• Check the accuracy of all fluid orders with the same care used to calculate drug dosages; remember that infants and young children become dehydrated or fluid-overloaded more rapidly than adults
• The following steps can be used to calculate maintenance fluid requirements for children:
• Note: Maintenance fluid is the amount of PO or IV fluid needed to maintain hydration in a healthy child; additional fluid may be needed to compensate for certain pathological states such as dehydration or sickle cell anemia crisis

Steps in Maintenance Fluid Calculation

1. Convert the child’s weight in pounds (lb) to kilograms (kg) by multiplying the number of lb by 0.45
2. Calculate 100 mL of fluid per kg/24 hr for the 1st 10 kg of body wt
3. Calculate 50 mL of fluid per kg/24 hr for the 2nd 10 kg of body wt
4. Calculate 10 to 25 mL of fluid per kg/24 hr for each kg of body wt over 20; specific amount added for kgs over 20 depends on patient size and condition
5. Add the products of steps 2, 3, and 4 to determine the mL of fluid needed per 24 hours (eliminate any step that is not applicable to the wt of the child)

Note: Twelve percent of the total maintenance fluid may be added for every degree (Celsius or Centigrade) of body temp over 37.5.

Examples of Maintenance Fluid Calculation for Children

For a 15-Pound Child

• Convert 15 lb to kg by multiplying 15 × 0.45 = 6.75 kg
• Or lbs by 2.2 to convert lbs to kgs
• Allow 100 mL/kg for each of the 6.75 kg = 675 mL
• Divide 675 by 24 (hr) to determine the number of mL fluid/hr = 28
• When using a microdrop device, the rate of IV flow will be the same as mL/hr = 28 gtts/min

For a 70-Pound Child

• Convert 70 lb to kg by multiplying 70 × 0.45 = 31.5 kg
• Allow 100 mL/kg for each of the 1st 10 kg = 1000 mL
• Allow 50 mL/kg for each of the 2nd 10 kg = 500 mL
• Allow 20 mL/kg for each of the remaining 11.5 kg = 230 mL
• Note that the physician will determine the exact amount (usually 10–25 mL per kg) for the 3rd and additional kg, based on the child’s condition
• Add 1000 mL + 500 mL + 230 mL = 1730 mL
• Divide 1730 by 24 (hr) to determine mL/hr = 72 mL/hr
• The IV rate is 72 gtts/min