Electrolytes: Oral Electrolyte Solutions

Abstract

Oral electrolyte solutions are used widely for rehydration in diarrheal illness and to maintain hydration during vigorous exercise. In diarrheal illness, an oral rehydration solution (ORS) typically is preferred over intravenous fluids except for patients with severe dehydration. The preferred ORS is one similar to the glucose-containing reduced osmolarity World Health Organization ORS. There also are polymer-based solutions that use rice or wheat as the source of carbohydrates but these are not widely recommended. Use of other liquids, such as sport drinks, juice, soft drinks, and chicken broth is not recommended, though these can be considered for patients with no or mild dehydration. For maintaining hydration during exercise, particularly vigorous high-intensity exercise, recommendations are to consume fluids (ie, 5 to 7 mL/kg) and a sodium-containing snack at least 4 hours before. During exercise, individuals require 200 to 800 mL/hour of liquid that should contain 20 to 30 mEq/L of sodium. Carbohydrate intake is recommended during high-intensity exercise. Intake of excessive sodium-free fluids should be avoided to prevent exercise-induced hyponatremia. Additional fluids (ie, 1.5 L/kg of weight lost) can be consumed after exercise to restore hydration. Vitamin and mineral supplements are not recommended routinely for athletes unless known deficiencies exist.