This calculator is for general information and education. It is not medical advice and does not replace the judgment of a doctor, nurse or pharmacist who knows the full clinical picture.
Judging dehydration at the bedside
Gastroenteritis is one of the most common reasons young children see a doctor. Most cope well at home, but a child who loses too much fluid through vomiting and diarrhea can become dehydrated quickly. Weighing the child before and after the illness is the most accurate measure, but the earlier weight is rarely known. In 2004, Jeremy Friedman and colleagues in Toronto published the Clinical Dehydration Scale (CDS), a short score based on four signs that any doctor or nurse can check in a minute.
The four signs
| Sign | 0 | 1 | 2 |
|---|---|---|---|
| General appearance | Normal | Thirsty, restless, or lethargic but irritable when touched | Drowsy, limp, cold or sweaty |
| Eyes | Normal | Slightly sunken | Very sunken |
| Mucous membranes (tongue) | Moist | Sticky | Dry |
| Tears | Tears | Decreased | Absent |
Reading the score
- 0: no dehydration, less than 3% of body weight lost.
- 1 to 4: some dehydration, about 3 to 6%.
- 5 to 8: moderate to severe dehydration, 6% or more.
The scale was developed for children aged 1 month to 3 years with gastroenteritis.
Worked example
A 2-year-old weighing 26 lb (11.8 kg) has had diarrhea for two days. The child is thirsty and restless (1), the eyes are slightly sunken (1), the tongue is sticky (1) and there are still tears (0). The score is 3: some dehydration.
- Oral rehydration solution over 4 hours, at 75 mL/kg: about 885 mL (30 fl oz).
- After each watery stool, an extra 10 mL/kg: about 118 mL (4 fl oz).
- The estimated fluid deficit is at least 30 mL/kg, about 354 mL.
Oral rehydration
For mild to moderate dehydration, oral rehydration works as well as an IV drip in most children. The key is a proper oral rehydration solution (ORS), such as Pedialyte or a store-brand equivalent, which balances salt and sugar so the gut absorbs water efficiently. Juice, soda and sports drinks contain too much sugar and too little salt, and can make diarrhea worse.
Give small amounts often: a teaspoon (5 mL) every minute or two with a syringe or spoon. Most children who vomit can still keep down small, frequent sips. Breastfed babies should continue nursing. Once rehydrated, children should go back to their usual diet; there is no need to restrict food.
When to get help quickly
- A score of 5 or more, or a child who is drowsy, floppy or hard to wake.
- No wet diaper or urine for 8 hours or more.
- Vomiting that prevents any fluid from staying down, or green vomit.
- Blood in the stool, severe belly pain or a high fever.
- A baby under 6 months old, or a child with a chronic illness.
Call 911 for a child who is unresponsive or struggling to breathe.