Rehydration solutions and domestic measurements
Cutting, W.A.
Lancet 2(8039): 663-664
1977
ISSN/ISBN: 0140-6736 PMID: 71480 DOI: 10.1016/s0140-6736(77)92532-6Document Number: 450207
Dr. Waterston (August 13, p. 355) encourages the use of domestic salt and sugar, measured in a traditional way using the mother's fingers, to prepare a rehydration fluid. This method, proposed by Church and publicized by Morley, is attractive because it utilizes ingredients already available in many homes. The demonstration that sugar can safely replace glucose in the basic mixture reinforces this principle. Sedgwick and I reported that village mothers in India could be taught to mix the powder in local water vessels and that they achieved solutions with reasonably accurate composition. Unfortunately in a recent study in 2 tropical countries, the 2-finger pinch technique of measuring the salt has been found to have an unacceptably wide variability and could result in cases of hypernatremia that would bring this invaluable treatment into disrepute. As displayed in tabular form, the pinch weight of crude salt in India measured 1.63 g, of refined salt 2.27 g, refined salt in Trinidad 0.96 g, and refined salt in England 0.42 g. There was no statistical correlation between finger size and the weight of a pinch of salt, and the wide intercultural variations are probably due to different ways of using the hands in cooking and eating. Inaccuracies in the measurement of solute ingredients, especially salt, could be exaggerated in inaccuracies in measuring the solvent, water. Consequently hand measurements cannot be recommended unless they have been carefully tested in the community in which they are to be used.