Reduced concentration oral rehydration solution

Note: This describes a method which is not advisable in some cases.
Please read carefully and Do Your Own Research.

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Reduced concentration oral rehydration solution (or reduced osmolarity oral rehydration solution) is less concentrated than traditionally used in oral rehydration therapy. Some tests have found it to result in "reduced need for unscheduled intravenous infusions, lower stool volume, and less vomiting compared with standard WHO rehydration solution."[1]. In contrast, [2]

However, concerns have been raised that this is unsuitable for universal use, as it may lead to a negative sodium balance in cholera patients, with very serious consequences.[3] For this reason starch-based oral rehydration solutions may be preferred methods of achieving the same effects with less risk,[verification needed] especially in serious cases.

Composition and usageEdit

See also Oral rehydration solution recipes for the conventional version.

The 2004 WHO recipe for home-made Oral Rehydration Salts:

Add to one litre of safe water:

  • Salt 1/2 small spoon (3.5 grams)
  • Sugar 4 big spoons (40 grams)

The standard, manufactured WHO/UNICEF glucose-based ORS solution contains:[verification needed]

Reduced osmolarity ORS grams/litre
Sodium chloride 2.6
Anhydrous Glucose 13.5
Potassium chloride 1.5
Trisodium citrate, dihydrate 2.9
Reduced osmolarity ORS mmol/litre
Sodium 75
Anhydrous Glucose 75
Chloride 65
Potassium 20
Citrate 10
Total Osmolarity 245

In the human body, the plasma osmolarity is about 285 mOsm/l.

The amount of rehydration that is needed depends on the size of the individual and the degree of dehydration. Rehydration is generally adequate when the person no longer feels thirsty and has a normal urine output. A rough guide to the amount of ORS solution needed in the first 4-6 hours of treatment for a mildly dehydrated person is:

  • Up to 5 kg (11 lb): 200 – 400 ml
  • 5-10 kg (11-22 lb): 400 – 600 ml
  • 10-15 kg (22-33 lb): 600 – 800 ml
  • 15-20 kg (33–44 lb): 800 – 1000 ml
  • 20-30 kg (44-66 lb: 1000 – 1500 ml
  • 30-40 kg (66-88 lb): 1500 – 2000 ml
  • 40 plus kg (88 lb): 2000-4000 ml

Questions and commentsEdit

  • Perhaps this is suitable when the patient is able to take some other food, and is not relying solely on the ORS? --Chriswaterguy 19:20, 11 May 2008 (PDT)
  • In the medical literature available through a Google search, this is referred to as reduced osmolarity oral rehydration solution. To make it more understandable to the lay person, I've changed it to reduced concentration oral rehydration solution, which doesn't have any hits online. Is there a better term to use? (Or... is it only the salt that's reduced, in which case it should be reduced salinity oral rehydration solution...)
  • ...or "Diluted ORS"? Though that sounds rather imprecise. Steve.mccrosky 21:55, 20 May 2008 (PDT)


  1. Reduced osmolarity oral rehydration solution for treating dehydration due to diarrhoea in children: systematic review -- Hahn et al
  2. Efficacy and safety of oral rehydration solution with reduced osmolarity in adults with cholera: a randomised double-blind clinical trial (CHOICE study group, ICDDRB) failed to find a difference in cholera patients.
  3. JAMA -- Clinical Concerns About Reduced-Osmolarity Oral Rehydration Solution; Efficacy and safety of oral rehydration solution with reduced osmolarity in adults with cholera: a randomised double-blind clinical trial. CHOICE study group, ICDDRB.

External linksEdit