Chapter 7.4.3 Dehydration


Dehydration tends to be overdiagnosed and its severity overestimated in children with severe acute malnutrition because it is difficult to determine dehydration accurately from clinical signs alone. Assume that all children with watery diarrhoea or reduced urine output have some dehydration. It is important to note that poor circulatory volume or perfusion can co-exist with oedema.


Do not use the IV route for rehydration, except in cases of shock. Rehydrate slowly, either orally or by nasogastric tube, using oral rehydration solution for malnourished children (5–10ml/kg per h up to a maximum of 12 hours). The standard WHO ORS solution for general use has a high sodium and low potassium content, which is not suitable for severely malnourished children. Instead, give special rehydration solution for malnutrition, ReSoMal.

Give the ReSoMal rehydration fluid orally or by nasogastric tube, more slowly than you would when rehydrating a well-nourished child:

  • Give 5 ml/kg every 30 min for the first 2 h.
  • Then give 5–10 ml/kg per h for the next 4-10 h on alternate hours, with F-75 formula. The exact amount depends on how much the child wants, the volume of stool loss and whether the child is vomiting.

If not available then give half strength standard WHO oral rehydration solution with added potassium and glucose as per the ReSoMal recipe below, unless the child has cholera or profuse watery diarrhoea.

If rehydration is still required at 10 h, give starter F-75 instead of ReSoMal, at the same times. Use the same volume of starter F-75 as of ReSoMal.

If in shock or severe dehydration but cannot be rehydrated orally or by nasogastric tube, give IV fluids, either Ringer’s lactate solution with 5% dextrose or half-strength Darrow’s solution with 5% dextrose. If neither is available, 0.45% saline with 5% dextrose should be used.


During rehydration, respiration and pulse rate should fall and urine start to be passed. The return of tears, a moist mouth, less sunken eyes and fontanelle, and improved skin turgor are also signs that rehydration is proceeding, but many severely malnourished children will not show these changes even when fully rehydrated. Monitor weight gain.

Monitor the progress of rehydration every 30 min for 2 h, then every hour for the next 4–10 h. Be alert for signs of overhydration, which is very dangerous and may lead to heart failure. Check for:

  • weight gain to ensure that it is not quick and excessive.
  • increase in respiratory rate
  • increase in pulse rate
  • urine frequency (Has the child urinated since last checked)
  • enlarging liver size on palpation
  • frequency of stools and vomit.

If you find signs of overhydration (early signs are respiratory rate increasing by 5/min and pulse rate by 25/min), stop ReSoMal immediately and reassess after 1 h.


Measures to prevent dehydration due to continuing watery diarrhoea are similar to those for well-nourished children (see treatment plan A) except that ReSoMal fluid is used instead of standard ORS.

If the child is breastfed, continue breastfeeding.
?Initiate re-feeding with starter F-75.
Give ReSoMal between feeds to replace stool losses. As a guide, give 50–100 ml after each watery stool.