70
Glass #2:
8 oz
(250ml)
water (boiled or treated)
1/4 tsp baking soda
However, these ingredients may not be available to remote travelers.
Plain salt and sugar solutions, similar to those used for heat/exercise replacement,
can be used for mild dehydration, but are not adequate for serious dehydration or
replacement of continuing high losses. For mild dehydration, partial maintenance, or
supplementation, or where nothing else is available, rice water, fruit juice, coconut milk,
or diluted cola drinks may suffice.
II. GUIDELINES FOR FLUID REPLACEMENT
Achieve replacement of estimated fluid deficit in about four hours by giving 50 ml/kg
body weight for mild dehydration and 100 ml/kg for moderate dehydration. This means
that for mild dehydration, an adult should drink 250 ml of oral rehydration solution every
30 minutes for the first 4 to 6 hours. Children should drink 200 to 250 ml/hour. In
addition, they may drink water as desired. Give infants under 3 months a 100 ml dose
each hour with every third dose replaced by plain water. Ingestion of frequent, small
amounts, rather than rapid ingestion, minimizes vomiting. Fluid deficit is replaced within
12 hours in 90% of patients. Determine maintenance fluids by estimating or measuring
stool losses plus normal maintenance requirements. Since this is not often possible in the
field, give 10 to 15 ml/kg body weight/diarrheal stool.
At least 90% of patients during diarrhea epidemics can be successfully
rehydrated using only ORS. Failure of ORS occurs when stool losses exceed oral intake.
Vomiting, unless frequent and protracted, does not preclude rehydration with oral
solutions. Fluids may be administered by nasogastric tube when the patient is unable or
unwilling to drink adequate fluids. Intravenous fluids can be reserved for the initial
hydration of patients with shock, obtundation, seizures, or intractable vomiting. When IV
fluids are necessary, ORS usually can be initiated within 4 hours and exclusively used
within 24 hours.
III. CONTROVERSIES
A. Does ORS cause hypernatremia in patients without cholera? Many physicians in
developed countries avoid ORS because of an unsubstantiated concern for hypernatremia
in small children. This concern has led to lower sodium concentrations (50 to 75 mEq/L)
in commercial ORS sold in the United States and recommendations to use the higher
concentration only for initial rehydration then lower concentrations for maintenance. This
complexity can be avoided if plain water or formula is alternated with ORS in the
maintenance phase of treatment.
B. Are electrolyte replacement drinks necessary for wilderness activities? Cases of severe
hyponatremia in endurance athletes and recreational hikers in hot climates have been
reported, and were probably caused by "water intoxication." As sweat losses increase
with environmental heat stress and prolonged exercise, electrolyte replacement becomes
more important. Most wilderness sports such as hiking, climbing, or skiing offer frequent
opportunities to rest and ingest food and fluids. If snack foods are eaten regularly, plain
water will be safe for fluid replacement. Unfortunately, many hikers favor snack foods
that are high in carbohydrates and fats (such as candy) but low in sodium. Some
