e-Library of Evidence for Nutrition Actions (eLENA)

Initial treatment of dehydration for severe acute malnutrition

Biological, behavioural and contextual rationale

Ashley Carmichael
April 2011

Dehydration is defined as the condition that results from excessive loss of body water 1. In severe acute malnutrition, dehydration is caused by untreated diarrhoeal disease which leads to the loss of water and electrolytes 2. Severe acute malnutrition and diarrhoeal disease run in a vicious cycle, each making the other more severe and more likely to occur.

Diarrhoeal disease is caused by poor cleanliness and contact with contaminated food or water. It is widespread in developing countries where about one billion people do not have access to clean water and 2.5 billion people do not have access to basic sanitation 2. Every year, there are two billion cases of diarrhoeal disease worldwide, which kills approximately 1.5 million children2.

Dehydration with severe acute malnutrition can be difficult to identify, as many of the typical signs such as skin elasticity are not reliable 3. Useful indicators include an eagerness to drink, exhaustion, cool and moist extremities, weak or absent radial pulse, and reduced or absent urine flow 3. So that proper treatment can be given, it is important to differentiate between dehydration and septic shock, which have several symptoms in common. A history of diarrhoea indicates that dehydration is present and can be treated accordingly 3.

The identification of dehydration is the same for all diarrhoeal disease. However, for treatment purposes, the distinction must be made between cholera and other diarrhoeal diseases as causes of the dehydration. Cholera is differentiated by the presence of acute watery diarrhoea and has the ability to kill healthy people within a few hours 4.

In areas where severe acute malnutrition is a problem, multi-step programmes are used. The management of mild, moderate and severe dehydration, which is the third step in the initial treatment of severe acute malnutrition, takes place in the hospital.

Mild to moderate dehydration is characterized by thirst, restless or irritable behaviour, normal to slightly sunken eyes and a sunken fontanelle in infants. Signs of severe dehydration include lethargy or unconsciousness, poor drinking or inability to drink, lack of urine output, cool moist extremities, low or undetectable blood pressure, and a rapid and feeble pulse 5.

In people with severe acute malnutrition, mild and moderate dehydration caused specifically by cholera, should be immediately treated with oral rehydration salts (ORS) 4. ORS is a fluid that contains salt, sugar, potassium chloride and citrate to replenish the lost fluids and electrolytes that led to dehydration 6.

Where dehydration in severe acute malnutrition is caused by other diarrhoeal diseases, it is treated with an altered version of ORS called ReSoMal, which stands for the recommended oral rehydration salts solution for severely malnourished children 3. The difference in treatment stems from research that found the ratio of sodium to potassium in ORS to be too high for people with dehydration in severe acute malnutrition caused by all diarrhoeal diseases other than cholera. This solution could overload the heart and lead to cardiac failure 7. Therefore, to correct this problem, the solution for treatment of all causes of dehydration other than cholera was changed to ReSoMal, which is higher in potassium and lower in sodium than ORS 7.

In either treatment, the preferred method of rehydration for adults and children is by mouth, however if a child is drinking poorly, a nasogastric tube may be used. Severe dehydration caused by cholera should be treated with intravenous fluids 3. It is also important that the feeding of infants is not interrupted during rehydration, and that mothers should continue to breastfeed 3.

Signs of successful rehydration include the passing of urine, a lack of thirst, and the absence of other indicators of dehydration 3. Fluids should continue to be given to maintain hydration until diarrhoea has ceased 3.


1 Dorland. Dorland's illustrated medical dictionary. Philadelphia, W.B. Saunders, 2007.

2 Diarrhoeal disease fact sheet. Geneva, World Health Organization, 2009.

3 Management of severe malnutrition: a manual for physicians and other senior health workers. Geneva, World Health Organization, 1999.

4 WHO position paper on oral rehydration salts to reduce mortality from cholera. Geneva, World Health Organization, 2009.

5 The treatment of diarrhoea: a manual for physicians and other senior health workers (4th rev). Geneva, World Health Organization, 2005.

6 New formulation of oral rehydration salts (ORS) with reduced osmolarity. The United Nations Childrens’ Fund Supply Division, 2004 (Technical Bulletin, No. 9).

7 Golden MHN. Severe malnutrition. In: Weatherall DJ, Ledingham JGG, Warell DA eds. The Oxford textbook of medicine. Oxford, Oxford University Press, 1996:1278–1296.

8 Severe malnutrition: report of a consultation to review current literature. Geneva, World Health Organization, 2004.


The named authors alone are responsible for the views expressed in this document.

Declarations of interests

Conflict of interest statements were collected from all named authors and no conflicts were identified.