Rehydration Therapy

Rehydration is the cornerstone of treatment for cholera. Oral rehydration salts and, when necessary, intravenous fluids and electrolytes, if administered in a timely manner and in adequate volumes, will reduce fatalities to well under 1% of all patients.

Patients with severe acute malnutrition should receive oral rehydration with low-osmolarity ORS solution instead of the standard rehydration solution for diarrhea, ReSoMal. ReSoMal does not have sufficient sodium content to replace the losses from cholera 2. Breastfed infants should continue to breastfeed. Other types of fluids, such as juice, soft drinks, and sports drinks should be avoided.

Key Points About Rehydration
  • Rapid high-volume rehydration will save lives
  • Many patients can be rehydrated entirely with oral rehydration solution ORS)
  • Even if the patient gets intravenous (IV) rehydration, he/she should start drinking ORS as soon as he/she is able

Watch the following video: Managing Dehydration

Signs and Symptoms of Dehydration

  • Moderate Dehydration

  • Restlessness and irritability
  • Sunken eyes
  • Dry mouth and tongue
  • Increased thirst
  • Skin goes back slowly when pinched
  • Decreased urine
  • Decreased tears, depressed fontanels in infants
  • Severe Dehydration

  • Lethargy or unconsciousness
  • Very dry mouth and tongue
  • Skin goes back very slowly when pinched (“tenting”)
  • Weak or absent pulse
  • Low blood pressure
  • Minimal or no urine


  • Dehydrated patients who can sit up and drink should be given oral rehydration solution (ORS) immediately and be encouraged to drink. Other types of fluids, such as juice, soft drinks, and sports drinks should be avoided.
  • Offer ORS solution frequently, measure the amount drunk, and measure the fluid lost as diarrhea and vomitus.
  • Patients who vomit should be given small, frequent sips of ORS solution, or ORS solution by nasogastric tube.
  • ORS solution should be made with safe water. Safe water means the water has been boiled or treated with a chlorine product or household bleach 15 minutes before adding the pre-packaged oral rehydration salts.
  • The approximate amount of ORS (in milliliters) needed over 4 hours can also be calculated by multiplying the patient’s weight in kg by 75.
  • A rough estimate of oral rehydration rate for older children and adults is 100 ml ORS every five minutes, until the patient stabilizes.
  • If the patient requests more than the prescribed ORS solution, give more.
  • Patients should continue to eat a normal diet or resume a normal diet once vomiting stops.
  • For infants: Encourage the mother to continue breastfeeding.
  • Reassess the patient after 1 hour of therapy and then every 1 to 2 hours until rehydration is complete.
  • During the initial stages of therapy, while still dehydrated, adults can consume as much as 1000 ml of ORS solution per hour, if necessary, and children as much as 20 ml/kg body weight per hour.
  • The volumes and time shown are guidelines based on usual needs. If necessary, amount and frequency can be increased, or the ORS solution can be given at the same rate for a longer period to achieve adequate rehydration. Similarly, the amount of fluid can be decreased if hydration is achieved earlier than expected.

  • Patients with severe dehydration, stupor, coma, uncontrollable vomiting, or extreme fatigue that prevents drinking should be rehydrated intravenously.
  • For severe dehydration, start intravenous fluids (IV) immediately. If the patient can drink, give ORS solution by mouth while the IV drip is set up.
  • It is important to measure the amount of IV fluids delivered and measure the fluid lost as diarrhea and vomitus.
  • Reassess the patient every 10-15 minutes and continue hydrating. Monitor for signs of worsening dehydration or signs of fluid overload. The volumes and time intervals shown are guidelines provided on the basis of usual needs.
    • If necessary, the rate of fluid administration can be increased, or the fluid can be given at the same rate for a longer period, to achieve adequate rehydration. If hydration is not improving, give fluids more rapidly. 200ml/kg or more of intravenous fluids may be needed during the first 24 hours of treatment.
    • Similarly, the amount of fluid can be decreased if hydration is achieved earlier than expected.
    • If the patient requests more than the prescribed ORS solution, give more.
  • Switch from intravenous hydration to oral rehydration solution once hydration is improved and the patient can drink. This will conserve IV fluids and reduce the risk of phlebitis and other complications.
    • Nasogastric tubes can be used to administer oral rehydration solution if patient is alert but unable to drink sufficient quantities independently.

WHO Fluid Replacement or Treatment Recommendations
No dehydration ORS
Administer after each stool:
Age Volume of ORS
<2 years 50–100 ml, up to 500 mL/day
2–9 years 100–200 ml, up to 1000 mL/day
≥10 years As much as wanted, up to 2000 mL/day
Some dehydration ORS
Administer in first 4 hours:
Age Weight Volume of ORS
<4 months <5 kg 200–400 mL
4–11 months 5–7.9 kg 400–600 mL
1–2 years 8–10.9 kg 600–800 mL
2–4 years 11–15.9 kg 800–1200 mL
5–14 years 16–29.9 kg 1200–2200 mL
≥15 years 30 kg or more 2200–4000 mL
Severe dehydration Intravenous Ringer’s Lactate or, if not available, normal saline and ORS as outlined above. Do not give plain glucose or dextrose solution.
Administer up to 200 ml/kg IV fluids in first 24 hours
Age< 12 months
Timeframe Total volume
0–30 min 30 ml/kg*
30 min–6 h 70 ml/kg
6 h–24 h 100 ml/kg
Age≥ 1 year
Timeframe Total volume
0–30 min 30 ml/kg*
30 min–3 h 70 ml/kg
3 h–24 h 100 ml/kg
Age <1 year
Timeframe Total volume
0-60 min 30 ml/kg
1 h–6 h 70 ml/kg

*Repeat once if radial pulse is still very weak or not detectable

Signs of Adequate Rehydration

  • Skin goes back normally when pinched
  • Thirst has subsided
  • Urine has been passed
  • Pulse is strong

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