History of the development of oral rehydration therapy.

Humans have often used oral fluids to replace perceived losses of water, either instinctively or with a therapeutic orientation in the form of folk remedies. Replacement therapy with intravenous (IV) fluids was formally introduced in the last century for the treatment of patients with cholera. The modern implementation of oral replacement therapy was begun by pediatricians in the 1940s who used electrolyte solutions as maintenance therapy in mildly purging children with diarrhea. However, the scientific development of oral rehydration therapy (ORT) has occurred only in the last 30 years. Basic physiologic research in the 1950s demonstrated the cotransport mechanism of sodium and organic solutes (sugars and amino acids) in the intestinal cells, thereby establishing the scientific basis for ORT. The use of ORT based on scientific observations was first reported in 1964 from the Philippines by Phillips and coworkers. Research laboratories in Dhaka and Calcutta subsequently demonstrated that the mechanism of sodium and glucose cotransport remains intact in cholera patients and that oral solutions can successfully rehydrate and maintain hydration in these patients. Clinical studies carried out in Dhaka and Calcutta confirmed the efficacy of oral rehydration solutions (ORS) and showed that nearly 80% of IV fluid could be saved if patients were hydrated by the oral route. Further studies demonstrated the safety and efficacy of ORT in patients of all ages suffering from acute diarrhea of any cause. The use of ORT has substantially reduced morbidity and mortality from acute diarrhea, particularly after the World Health Organization adopted and promoted ORT on a worldwide scale. Researchers continue to search for better ORS formulations in terms of safety, efficacy, availability, and cost. Food-based ORS are a promising area of research. The use of a sound scientific method, the establishment of a close link between basic and clinical science, and the use of field studies have proved to be major assets in the development of ORT.