Dehydration in Children: Oral Rehydration, Signs of Dehydration, and When to Seek Care
Teach oral rehydration solution (ORS) in small, frequent amounts: 1 teaspoon (5 mL) every 1 to 2 minutes, increased as tolerated, with continued breastfeeding and an early return to the usual diet. No urine in 8 hours for an infant or 12 hours for an older child requires a same-day call; the same finding with lethargy or difficulty waking requires 911. An infant under 3 months with vomiting needs same-day care, and with fever, an immediate call.
Who needs this teaching
Parents of infants and children with acute gastroenteritis, usually viral. Infants and young children dehydrate faster than adults. They have a higher total body water content, a higher metabolic rate, a larger body surface area relative to weight, and immature renal concentrating ability. Acute weight loss is the most accurate measure of fluid loss.
The priority teaching points
- Oral rehydration solution. Use a commercial ORS for mild to moderate dehydration. Give 1 teaspoon (5 mL) every 1 to 2 minutes by spoon, oral syringe, or cup, and increase the amount as tolerated. The usual replacement is 50 mL/kg over 2 to 4 hours for mild dehydration and 100 mL/kg over 2 to 4 hours for moderate dehydration, or the volume the provider prescribes. Replace ongoing losses with 10 mL/kg for each diarrheal stool and 2 mL/kg for each episode of emesis. If the child vomits, wait 10 minutes and restart more slowly.
- Fluids to avoid. Do not use juice, soda, sports drinks, or broth for rehydration. Their high sugar content worsens osmotic diarrhea, and their electrolyte content does not replace losses. Do not give infants plain water alone. Do not dilute formula.
- Continued feeding. Continue breastfeeding throughout the illness, more often than usual. Resume full-strength formula and the usual age-appropriate diet within 3 to 4 hours of rehydration. Avoid restrictive diets; they provide inadequate protein and calories.
- Signs of dehydration. Count wet diapers or voids. Mild dehydration presents with thirst and slightly dry mucous membranes. Moderate dehydration presents with dry mucous membranes, decreased tears, sunken eyes, a sunken anterior fontanel, decreased urine output, irritability, and delayed capillary refill (normal is under 2 seconds). Severe dehydration presents with lethargy, cool mottled extremities, tachycardia, rapid deep breathing, and minimal urine output. Hypotension is a late sign.
- Medications. Do not give antidiarrheal medications unless prescribed. Do not give bismuth subsalicylate; salicylates in children are associated with Reye syndrome.
- Age and urgency. An infant under 3 months with vomiting requires same-day care; with a temperature of 100.4 F (38 C) or higher, call immediately. Green (bilious) vomit, blood in the vomit, or bloody stool requires immediate evaluation.
- Prevention. Perform hand hygiene after every diaper change and before food preparation. Keep the rotavirus vaccine series current.
Red flags the parent reports
| Call the provider the same day | Call 911 or the local emergency number |
|---|---|
| No urine in 8 hours for an infant or 12 hours for an older child, without lethargy | No urine with lethargy or difficulty waking |
| Dry mouth, no tears, sunken eyes, or a sunken fontanel | Limp, unresponsive, or very difficult to wake |
| Vomiting of all fluids, or vomiting that lasts more than 24 hours | Cool, mottled, blue, or gray skin |
| Infant under 3 months with vomiting; with a temperature of 100.4 F (38 C) or higher, call immediately | Rapid, deep breathing |
| Green vomit, blood in the vomit, or bloody stool: call immediately or go to the emergency department | Seizure |
Teach-back questions
- "Show me how much solution you will give and how often."
- "What will you do if your child vomits after a drink?"
- "Which drinks will you avoid?"
- "How many hours without a wet diaper mean you call?"
- "Which signs mean you call 911?"
Teaching tips
- Demonstrate measuring 5 mL with an oral syringe, and use a timer.
- Write the child's weight and ORS goal on the handout.
- Explain that ORS replaces fluid and electrolytes; it does not stop diarrhea.
Read more on NCLEXPace
- Electrolyte Imbalances: One Table for All of Them
- Pediatric Vital Signs by Age: The Only Table You Need
- IV Fluids and Tonicity: Follow the Water
Sources
- King CK, Glass R, Bresee JS, Duggan C. Managing Acute Gastroenteritis Among Children: Oral Rehydration, Maintenance, and Nutritional Therapy. MMWR Recomm Rep. 2003;52(RR-16):1-16.
- Guarino A, et al. European Society for Pediatric Gastroenterology, Hepatology, and Nutrition/European Society for Pediatric Infectious Diseases Evidence-Based Guidelines for the Management of Acute Gastroenteritis in Children in Europe: Update 2014. J Pediatr Gastroenterol Nutr. 2014;59(1):132-152.
- Shane AL, et al. 2017 Infectious Diseases Society of America Clinical Practice Guidelines for the Diagnosis and Management of Infectious Diarrhea. Clin Infect Dis. 2017;65(12):e45-e80.
- Bismuth Subsalicylate Oral Suspension: FDA Drug Facts labeling (DailyMed).
Why this matters for the NCLEX
Teaching is effective when the parent states, "I will give one teaspoon of oral rehydration solution every 1 to 2 minutes," and "I will keep breastfeeding my baby." Statements requiring further teaching include, "I will give apple juice and sports drinks," "I will stop all food until the diarrhea stops," and "I will give an antidiarrheal medicine from the pharmacy."
Frequently asked questions
Why does the parent give small, frequent amounts instead of a full cup?
Small volumes are absorbed without triggering more vomiting. Most children with vomiting tolerate oral rehydration given this way.
Does oral rehydration solution stop diarrhea?
No. ORS replaces water and electrolytes; it does not shorten the diarrhea. Continued feeding supports recovery of the intestinal lining.
NCLEX high-yield tips and questions on this topic
Pyloric Stenosis vs IntussusceptionTell projectile nonbilious vomiting from colicky pain with currant jelly stools, correct fluids and electrolytes first, and know the follow-up care.3,200+ NCLEX questions with think-like-a-nurse rationales, unfolding case studies and adaptive readiness exams. Start with free practice questions, then choose a plan when you are ready.
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