Maintenance Fluid Calculations | Holliday Segar formula & 4-2-1 rule

Maintenance Fluid Calculator | Holliday Segar Method

Maintenance Fluid Calculator determine maintenance IV fluid rates uses the Holliday Segar formula and the 4-2-1 rule. The “4-2-1 rule” is most widely used for adults and pediatric maintenance fluid calculations.

The maintenance fluid calculator uses the Holliday Segar method and the 4-2-1 rule to determine the daily and hourly need for fluids in both adults and pediatric patients. In addition to determining the appropriate pediatric maintenance fluids, you can also calculate the correct size of the pediatric fluid bolus to administer in emergencies.

Other maintenance fluid calculators have been derived and employed, however the “4-2-1” rule remains the most widely used for adults and pediatric populations secondary to its ease of calculation

How to use maintenance fluid calculator?

Determine whether to use the maintenance fluids calculator, keeping in mind its limitations. Do not use it for newborns under 14 days old, as it overestimates fluid requirements. Additionally, the formula is not suitable for children weighing less than 3 kilograms. The calculator will provide warnings for these cases.
Input the child’s weight in kgs (for weigth in pounds select lbs)
You will get two results. The first is daily maintenance fluids — the fluid needed for the whole day — to be given within 24 hours (mL/24hr).
In the second line, you’ll see the Fluids flow rate (mL/hr). It tells you how fast the intravenous infusion should be.

Keep reading if you would like to find out:

What is maintenance fluid?
What is the Holliday Segar Formula, and how can you use it to calculate Maintenance Fluid?
Holliday Segar Formula and 4-2-1 Rule.
How to calculate maintenance fluid using holliday segar formula and 4-2-1 rule?
Maintenance fluid calculation examples and more.

One of the primary objectives of maintenance IV fluid therapy is to provide water to meet physiologic losses (insensible loss + urine loss). In a study published in 1957, in the Journal Pediatrics, Malcolm Holliday and William Segar developed a simple scheme which could be easily remembered to calculate the maintenance water needs in hospitalized patients.

Maintenance fluid

Maintenance fluid can be defined as the amount of fluid required to compensate for ongoing fluid losses, thus maintaining steady state in the body. It can be given by intravenous routes or oral routes (if patient can tolerate orally) or both.

SENSIBLE LOSS & INSENSIBLE LOSS:

The body classifies water losses into two types: SENSIBLE LOSS (which includes urine and faecal water) and INSENSIBLE LOSS (which includes perspiration and respiration).

Holliday Segar Method

Holliday Segar Method is a widely acceptable method of calculating maintenance fluid, especially in children. It helps to estimate the fluid requirement in 24 hours. The method is based on the weight of patient in kilogram. This formula relates water loss to the caloric expenditure that is, for every 100 kilocalories burned, the patient utilizes 100ml (in other words, under normal resting conditions, 1 ml of water is required to metabolize 1 kcal).

The commonly used method for approximating water loss (and therefore the water requirement) is based off of the Holliday-Segar Method.

Holliday Segar Formula

The Holliday-Segar Formula approximates daily fluid loss, and therefore the daily fluid requirements, as follows:

Maintenance Fluid Rate is calculated based on weight (mL/day).

100 ml/kg/day for 1st 10kg of body weight
50 ml/kg/day for 2nd 10 kg of body weight (11kg – 20kg)
20 ml/kg/day for any kilogram of body weight above 20kg (> 20kg)

Holliday Segar 4 -2-1 Rule

The delivery pumps used in hospitals are designed to be programmed for an hourly infusion rate (mL/hr). To determine the hourly rate of fluid maintenance required for a child based on their body weight this Holliday Segar formula has been further simplified, with the hourly requirement referred to as the “4-2-1 rule”

Maintenance Fluid Rate is calculated based on weight (mL/hr).

4 ml/kg/hr for 1st 10kg of body weight
2 ml/kg/hr for 2nd 10 kgof body weight(11kg – 20kg)
1 ml/kg/hr for any kilogram of body weightabove 20kg (> 20kg)

This online maintenance fluid calculator uses both the Holliday-Segar Formula and the 4-2-1 Rule to determine maintenance fluid requirements.

This maintenance fluid calculations:

Estimates the volume required per kg to maintain hydration in healthy children
Accounts for insensible losses (from breathing, through the skin, and in stool)
Allows for excretion of the daily excess solute load (urea, creatinine, electrolytes, etc) in a volume of urine with similar osmolarity to plasma

Maintenance fluid Calculations Example

In the end of these maintenace fluid calculations examples you will know how to calculate pediatric maintenance fluid requirements using both Holliday Segar formula and 4 2 1 rule.

What will be the maintenance fluid requirement for a child weighing 6kg? Using both Holliday Segar Formula and 4-2-1 Rule.

For full maintenance fluid — Holliday-Segar method

Weight= 6kg (this falls within first 10kg)
Formula: 100 ml/kg/day for 1st 10kg of body weight

Thus, = 100ml × 6 = 600ml

Therefore, the child requires 600ml of fluid in 24hrs (per day).

To express it in ml per hour, divide 600ml by 24hrs = 25 mL/hr

For hourly maintenance rate – 4-2-1 Rule

Using 4, 2, 1 formula (Holliday – Segar’s Formula) More accurate for ml/hr calculation.

Weight= 6kg (this falls within first 10kg)

Formula: 4 ml/kg/hr for 1st 10kg of body weight

Thus, = 4ml × 6 = 24ml/hr

Therefore, the child requires 24ml of fluid in per hour.

How much fluid would a child of 15 kg need?

Using Holliday-Segar Formula (mL/day)

Break Down the Weight:

For a 15 kg child, we will break down the weight into the appropriate categories:
- The first 10 kg
- The remaining 5 kg (since 15 kg falls within the 11-20 kg range)

Calculate Fluid Requirement for Each Category:

First 10 kg:
- 10 kg × 100 ml/kg = 1000 ml
Next 5 kg (11 to 20 kg range):
- 5 kg × 50 ml/kg = 250 ml

Sum the Fluid Requirements:

Add the amounts calculated for each weight category:

Therefore, the child requires 1250ml of fluid in 24hrs (per day).

To express it in ml per hour, divide 1250ml by 24hrs = 52 mL/hr

Using 4-2-1 Rule (mL/hr)

First 10 kg: 4 mL/kg/hr x 10 kg = 40 mL/hr
Next 5 kg: 2 mL/kg/hr x 5 kg = 10 mL/hr
Total hourly rate: 40 + 10= 50 mL/hr

Using the 4-2-1 rule, a 15 kg child requires 50 ml of maintenance fluids per hour, which totals to 1200 ml per day.

Calculate the daily fluid requirements of a 10 year old boy who weighs 32 kg using the Holiday-Segar method & 4-2-1 Rule?

For full maintenance (mL/day) — Holliday-Segar method

First 10 kg: 100 mL/kg/d x 10 kg = 1000 mL/d
Next 10 to 20 kg: 50 mL/kg/d x 10 kg = 500 mL/d
Remaining 12 kg: 20 mL/kg/d x 12 kg = 240 mL/d
Total fluids per day: 1000 + 500 + 240 = 1740 mL/day

The total daily maintenance fluids requirement for a 32 kg child is 1740 mL/day.

For hourly maintenance rate (mL/hr) – 4-2-1 Rule

Using, 4- 2-1 formula ml/hr calculation.

First 10 kg: 4 mL/kg/hr x 10 kg = 40 mL/hr
Next 10 to 20 kg: 2 mL/kg/hr x 10 kg = 20 mL/hr
Remaining 12 kg: 1 mL/kg/hr x 12 kg = 12 mL/hr
Total hourly rate: 40 + 20 + 12 = 72 mL/hr

A 32 kg child needs 72 ml of maintenance fluids per hour using the 4-2-1 rule, totaling 1728 ml per day.

Use Maintenance fluid calculator to calculate daily maintenance fluids and fluid flow rate (mL/hr) at once.

General Tips

Check that your answer makes sense clinically.
Triple check your work.
Have a colleague or pharmacist check your work.
Know general therapeutic drug doses for commonly administered medications.
Advice: Past, current, and future hydration status should always be considered when prescribing maintenance fluids, as under-dosing will lead to dehydration and renal insufficiency, and over-dosing may lead to fluid overload and edema in some patients.
Notes: The Holiday-Segar method can only apply to patients above 2 weeks of age. Additionally, the formula is not suitable for children under 3 kilograms.

FAQs

What are maintenance fluids?

Why are maintenance fluid calculations important?

Proper maintenance fluid calculations are essential to prevent dehydration or overhydration, both of which can lead to serious health complications.

What fluids are used for maintenance?

For maintenance needs, doctors use crystalloid solutions such as saline or Ringer’s lactate for the base of IV fluids. Glucose can be added along with electrolytes, such as potassium.

What is the Holliday-Segar method?

The Holliday-Segar method is a formula used to calculate daily maintenance fluid requirements based on a patient’s weight.

The method divides the weight into three categories:

100 ml/kg for the first 10 kg
50 ml/kg for the next 10 kg
20 ml/kg for each kilogram above 20 kg

What is 4-2-1 Rule?

Holliday Segar formula has been further simplified to determine the hourly rate of fluid maintenance required for a child based on their body weight, referred to as the “4-2-1 rule”

How do I calculate maintenance fluids for children?

You calculate maintenance fluids for children by using established formulas such as the Holliday-Segar method or the 4-2-1 rule, which are based on the child’s weight and specific fluid needs.

To calculate the volume of fluid to be administered according to the 4-2-1 rule, which provides hourly fluid requirements, you can use the following guidelines:

For the first 10 kilograms (3-10 kg) — 4 ml/kg/h.
For the next 10 kilograms (11-20 kg) — 2 ml/kg/h.
For weights above 20 kilograms — 1 ml/kg/h.

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