# The Holliday-Segar Method

In the Holliday-Segar Method, fluid and electrolyte requirements are empirically based on the caloric needs of the average hospital patient.  This caloric expenditure is approximated based on body weight using the following table:

 For each kilogram in this range Daily caloric cost per kilogram 1-10 kg 100 kcal/kg/day 11-20 kg 50 kcal/kg/day >20 kg 20 kcal/kg/day

For every 100 kcal expended, a certain amount of fluid is lost either through "insensible water loss" or through renal function; a small amount is generated through oxidation of carbohydrates and tissue catabolism.  Also, for every 100 kcal expended, electrolytes are lost in the following proportions:

 Na 3 mEq per 100 kcal/day K 2 mEq per 100 kcal/day Cl 2 mEq per 100 kcal/day

Example:  Calculate the daily fluid requirements of a 10 year old boy who weighs 32 kg using the Holiday-Segar method:

 Kcal expended 10*100 + 10*50 + 12*20 1740 kcal H20 required 1740 kcal * 100 cc/100 kcal 1740 mL H2O Na  required 1740 kcal * 3 mEq/100 kcal 52.2 mEq Na K required 1740 kcal * 2 mEq/100 kcal 34.8 mEq K Cl required 1740 kcal * 2 mEq/100kcal 34.8 mEq Cl

Given good renal function and no overriding concerns about excess sodium, a maintenance fluid to provide at least the required amount of sodium.  Potassium is usually added after the patient's first void in an amount that will yield the above maintenance level.  Chloride is usually not a concern in and of itself, but is a passive ion.  A table of common solutions can be consulted to pick an appropriate solution.

In this case, the target solution should have 52.2 mEq Na per 1.74 liters, or 30 mEq Na per liter.  The closest solution is the 34.2 mEq/L found in 0.2% saline.  Each liter should also contain 20 mEq of potassium.

The Holiday-Segar can be used to quickly estimate fluid requirements in terms of mL/hour (a useful way of expressing it, since this is how IV infusion pumps are programmed):

 For each Kilogram in the Range Add to Daily Requirement Add to Hourly Requirement 0-10 kg 100 mL 4 mL (~ 100/24 hours) 11-20 kg 50 mL 2 mL >20 kg 20 mL 1 mL

Thus, for a 45 kg girl, the maintenance IV fluid rate would be 4*10 + 2*10 + 35*1 = 95 mL/hour.

Notes:
1.  The Holiday-Segar method can only be applied to patients above 2 weeks of age.
2.  This method does not take into consideration caloric expenditures above average, or take into account on-going fluid losses; a more rigorous method would be the caloric method.