GastroSAM - Severe malnutrition

It’s estimated that 17 million children worldwide are severely undernourished. The most extreme form – severe acute malnutrition, or SAM – is a leading cause of paediatric hospital admissions across Africa. Many children hospitalised with SAM have additional complications including gastroenteritis leading to dehydration. Dehydration complicating gastroenteritis results in much worse outcomes indicating the current management of this complication is sub-optimal.  

For more than 30 years, international guidance has advised against using intravenous fluids in children with SAM and severe dehydration, recommending only rehydration solutions orally, often via a nasogastric tube. This is based on an expert opinion that children with SAM have a weaker functioning heart and may not be able to tolerate intravenous rehydration or standard saline solutions – which can in some cases lead to complications, such as fluid overload and heart failure. Furthermore, these guidelines also advise against using standard WHO oral rehydration solutions (ORS) because of concerns about sodium overload and potential heart failure. Instead, clinicians have been advised to use ReSoMal. 

 

However, neither of these recommendations were supported by strong trial evidence, particularly in Africa. More recent evidence provided by two studies of myocardial function conducted in Africa has demonstrated that the malnourished heart  function[1], including response to intravenous fluids are the same as in non-malnourished children. In light of the poor outcomes and new evidence indicating that the heart function in SAM is preserved, the GASTROSAM trial was set up to reappraise these guidelines.  

For children with severe dehydration, published in 2025 in the New England Journal of Medicine [2], was carried out in Niger, Nigeria, Uganda and Kenya. It involved the treatment of 292 children aged 12 and under hospitalised with SAM, with dehydration caused by diarrhoea.   

The trial compared the safety of different rehydration strategies, with the children randomised into one of three groups: 

  • Current standard of care recommended by the WHO, based on oral rehydration  
  • Rapid intravenous (IV) rehydration, typically used for non-malnourished children  
  • Slow IV rehydration, the same volume of fluid as for rapid IV rehydration but administered slowly  

The trial found no evidence of a difference in mortality with IV treatment after 96 hours, compared to the standard control strategy. In fact, among the children in the trial, mortality overall was lower than expected, although this is likely to be due to the close care and monitoring provided to the children during the trial.  

Most importantly, they found no events of heart failure or fluid overload – indicating that the intravenous approaches to rehydration were not harmful. In fact, they found that the standard oral strategy often meant that children needed to have a nasogastric tube fitted to deliver the rehydration fluids, and that this was associated with more episodes of vomiting and development of shock. 

The findings open the possibility of review of existing guidance worldwide; in particular, a simplification of the recommendations that would remove the distinction between rehydration treatments for children who are malnourished and for those who are not, with the effect of more widespread adoption of intravenous rehydration.  

The findings of this second study from the Gastroenteritis in Severe Malnutrition (GASTROSAM) trial, published in 2026 in The Lancet Child and Adolescent Health [3] compared a standard formula of oral rehydration salts (WHO-ORS) – a diluted mix of salt and electrolytes – to the standard treatment for malnutrition a low-sodium rehydration solution (ReSoMal). 

The trial involved 415 children, also carried out in Niger, Nigeria, Uganda and Kenya, found: 

  • that, at 24 hours, both treatments produced similar improvements in blood sodium levels; 
  • that, at eight hours, severe low sodium levels (hyponatraemia) were more common in the children receiving ReSoMal than those receiving WHO-ORS. (Severe hyponatraemia increases the risk of early death.); 
  • no evidence of fluid overload; 
  • Similar survival rates. 

These findings suggest that WHO-ORS can be used safely in severely malnourished children. The authors recommend that protocols be simplified in order to:

  • Potentially reduce preventable deaths;
  • Make treatment more available ;
  • Potentially enable earlier treatment in community settings.
  1. Brent B, Obonyo N, Akech S, et al. Assessment of Myocardial Function in Kenyan Children With Severe, Acute Malnutrition: The Cardiac Physiology in Malnutrition (CAPMAL) Study. JAMA Netw Open 2019; 2(3): e191054.
  2. Maitland K, Ouattara SM, Sainna H, et al. Intravenous Rehydration for Severe Acute Malnutrition with Gastroenteritis. The New England journal of medicine 2025; 393(13): 1257-68.
  3. Maitland K, Sainna H, Connon R, et al. Oral rehydration for severe malnutrition in children with moderate and severe dehydration (GASTROSAM): a phase 2, open-label, superiority randomised controlled trial. Lancet Child Adolesc Health 2026; 10(5): 319-29.