Sodium content of oral rehydration solutions: a reappraisal.

Abstract

Proper choice of oral rehydration solution, with regard to sodium content, is a conflicting issue to general practitioners and pediatricians. World Health Organization (WHO) recommendations of oral rehydration solution containing 90mmol/1 sodium, have been effective throughout developing countries worldwide. In developed countries, however, such as England, this recommendation seems inappropriate; a recommendation of 50 - 60 mmol/1 sodium with 90 -111mmol/1 glucose is preferred. This combination will eliminate the need for free water recommended by the WHO maintenance therapy. Normonatraemia is maintained, and hyponatraemia and hypernatraemia can both be corrected. Sodium content is adequate in replacing stool loss resulting from viral and bacterial diarrheas. Iatrogenic hyponatraemia and hypernatraemia do not occur as they would with oral rehydration solutions with low (30-35) or high (90mmol/1) sodium concentration. Solutions containing 50-60 mmol/1 sodium is safer in neonates and young infants with immature renal functions, incapable of properly distributing increased sodium leads. Glucose concentration necessary to make oral rehydration with 50 - 60 mmol/1 isotonic, or hypotonic, resembles WHO - ORS, but is half that in 30-35 mmol/1 sodium solutions. In controlled clinical trials, oral rehydration solutions with 50-60 mmol/1 sodium have proven safe, and performance was compatible with WHO-ORS. For both rehydration and correction of acidosis, the solution proved effective. When oral rehydration solution sodium, concentrate is below 90 mmol/1, errors in reconstituting may be common, but offers less risk resulting in dangerous hypernatraemia. An "all purpose" physiological oral rehydration solution would make oral rehydration therapy, more economical, simpler, and safe in developed countries worldwide.