Holliday-Segar formula
The Holliday-Segar formula is a formula to help approximate water and caloric loss (and therefore the water requirements) using a patient's body weight.[1] Primarily aimed at pediatric patients, the Holliday-Segar formula is the most commonly used estimate of daily caloric requirements.[2] To date, the formula continues to be recommended in the current clinical practice guidelines of the American Academy of Pediatrics, American Society of Parenteral and Enteral Nutrition, and National Health Service.[3][4][5] Developed in 1957 by Drs. Malcolm A. Holliday and William E. Segar while at the Indiana University School of Medicine, the researchers concluded a non-linear relationship between energy expenditure and weight alone to determine fluid requirements.
| 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 |
Worked example
To estimate the daily fluid requirements of a 9-year-old boy who weights 32 kg, 10*100 + 10*50 + 12*20 = 1740 kcal per day. At a 1 kcal / 1 mL conversion, the daily H20 requirements would therefore be 1740 mL.
Limitations
While generalizable to most cohorts, the Holliday-Segar formula may inadequately estimate caloric requirements in patients affected by fever, hypothermia, or increased activity states (i.e., hyperthyroidism or status epilepticus).[2] The formula can also only be applied to patients above 2 weeks of age.