| Dr Sujit K Bhattacharya |
July 29, is observed as ORS Day around the world. The now very ubiquitous ORS, stands for Oral Rehydration Salt solution which is extensively used for the prevention and correction of dehydration due to acute diarrhoeal disease. The solution has been in use in India over the past few decades and in remote interiors of the country, it is sometimes the first step to saving a critically dehydrated child.
Development of ORS and Oral Rehydration Therapy (ORT), which is today almost internalised by public health workers, is the culmination of several discoveries in the disciplines of physiology, pathology, chemistry and clinical and community trials.
Physiologists in the 40s described the carrier mediated absorption of sodium and water in the presence of glucose across the intestinal brush border membrane. It was also observed that in diarrhoea caused by cholera there is no structural damage to the intestinal mucosa and hence fluid absorption remains intact.
Subsequently, the formulation of ORS was developed which contains sodium chloride 3.5 g., potassium chloride 1.5 g., sodium bicarbonate 2.5 g., or tri-sodium citrate, dihydrate and anhydrous glucose to be dissolved in one litre of drinking water.
Studies have shown that ORS is effective in 95 per cent of cases of mild to moderate dehydration in diarrhoea. Severe cases of dehydration usually require immediate replacement of fluid and electrolytes through the intravenous route to save the life of the patient. However, in the maintenance phase of severe dehydration (after correction of initial deficit) the status of hydration can be maintained with ORS.
Studies have demonstrated that ORS is also effective in the management of dehydration due to rotavirus diarrhoea and is also safe in neonates. Rotavirus diarrhoea which is highly contagious, resilient and deadly, affects mostly infants and children less than two years of age, sometimes leading to fatalities.
During the liberation war in 1971 in the border area of the then East Pakistan (now Bangladesh) a field trial showed that ORS was effective in combating dehydration during a cholera outbreak among inmates of a refugee camp.
Several clinical trials of ORS containing less glucose and/or less sodium revealed that such ORS is not only effective but also cuts down unscheduled intravenous to a large extent. This type of ORS is called hypo-osmolar ORS and is now recommended by the World Health Organisation (WHO) for universal use in the treatment of diarrhoeal dehydration of all etiologies and in all age groups.
ORS recommended by WHO does not reduce stool output nor shorten the duration and frequency of diarrhoea. In order to overcome these shortcomings of standard ORS, the concept was mooted that glycine fortified ORS may be more effective. However, clinical trials did not find much advantage over the existing ORS.
An editorial in The Lancet described ‘the development of ORS as potentially the most important discovery in the nineteenth century’. ORS has saved the lives of millions of children in poor country-setting. It is not only cheap and effective but also easy to use even by illiterate mothers and other care providers.
I may conclude by remarking that with such a strong weapon to combat acute diarrhoea that we have, its utilisation rate is urgently required to be scaled up.