Lessons · Nursing · maintenance fluids by the 4-2-1 rule
Maintenance fluids by the 4-2-1 rule the problem states
The rule, as the problem gives it: 4 mL/kg/h for the first 10 kg of weight, 2 mL/kg/h for the next 10 kg, and 1 mL/kg/h for every kilogram above 20; add the three pieces for the hourly rate.
Hone is a place to practise a career, one idea a day. This is one of its lessons, written out in full and free to read without an account.
In beta. This lesson was written for Hone and has not yet been checked by a licensed nurse. Practice material, not professional advice. What that means.
What it is for
A paediatric order is written from a weight, and the rate on the pump is the sum of three small multiplications. Done in three lines on paper it is easy; done in one line in your head it is where a kilogram gets counted twice.
How to think about it
Write the weight in kilograms. Split it: the first 10, the next 10, and whatever is left. Multiply each piece by its own number, 4, 2 and 1. Add the three. The answer is mL per hour; times 24 gives the day.
Worked example
Weight 32 kgThe weight in kilograms, converted first if the scale said pounds.
First 10 kg: 10 × 4 = 40 mL/hThe first piece.
Next 10 kg: 10 × 2 = 20 mL/hThe second piece, for the kilograms from 10 to 20.
Above 20 kg: 12 × 1 = 12 mL/hThirty-two less twenty is twelve.
Rate = 40 + 20 + 12 = 72 mL/hThe three pieces added. Times 24 would give the day's volume.
Your turn
A child of 15 kg. Write the kilograms that fall in the second band.
15 - 10 = kg
Solve one, graded on the server
The trap
Multiplying the whole weight by 4. A 30 kg child is not 120 mL/h; the first ten kilograms get 4, the next ten get 2 and the rest get 1, which comes to 70. The rule is three bands, not one rate.