Calculation of Maintenance of Fluids

Question 1

What is the 100/50/20 rule?

Answer 1

Maintenance of IV fluids for the first 24 hr period
100 mL/kg for the first 10kg
50mL/kg for the next 10 kg
20mL/kg for every kg over 20 (divide by 24 for hourly rate)

Question 2

What is the 4/2/1 rule?

Answer 2

Maintenance IV fluids for hourly rate
4mL/kg for first 10kg
2mL/kg for the next 10kg
1mL/kg for every kg over 20

Question 3

What is the maintenance for a 70Kg man for a 24 hour period?

Answer 3

using 100/50/20 rule
100X10kg=1000
50X10kg=500
20X50kg=1000
total=2500
Divided by 24h = 104mL/hr maintenance rate

Question 4

What is the maintenance for a 70kg man for hourly maintenance?

Answer 4

Using 4/2/1 rule 
4X10kg=40
2X10kg=20
1X50kg=50
Total 110mL/hr maintenance rate

Question 5

What is the common adult maintenance fluid?

Answer 5

D51/2 NS w/ 20 mEq KCl/L

Question 6

What is the common pediatric maintenance fluid?

Answer 6

D5 1/4 NS w/ 20mEq KCl/L (1/4 NS because of the decreased ability of children to concentrate urine)

Question 7

Why should sugar be added to maintenance fluid?

Answer 7

to avoid muscle breakdown

Question 8

What is the best way to assess fluid status?

Answer 8

I’s and O’s (urine output) unless the pt has cardiac or renal dysfunction in which case CVP or WP is often used

Question 9

What is the minimal urine output for a adult on maintenance IV?

Answer 9

30mL/hr

Question 10

What is the minimal urine output for an adult trauma patient?

Answer 10

50mL/hr

Question 11

What is a bolus and how should it be given?

Answer 11

Volume of fluid given IV rapidly (Eg 1l/hr) used for increasing intravascular volume

Question 12

What should be used when giving a bolus?

Answer 12

NS or LR isotonic fluids

Question 13

Why not combine bolus fluids w/ dextrose

Answer 13

may result in hyperglycemia

Question 14

What is the most common trauma resuscitation fluid?

Answer 14

LR

Question 15

What is the most common post op IV fluid after laparotomy?

Answer 15

LR or D5LR for 24 to 36hr followed by maintenance fluid

Question 16

After a laparotomy when should pt’s fluid be “mobilized”?

Answer 16

POD#3 classically - pt begins to mobilize the third spaced fluid back into the intravascular space