What is a suitable oral rehydration solution to replace sodium?

From the Guidelines

To replace sodium through a salt drink, it is recommended to use an oral rehydration solution (ORS) with a sodium content of 75-90 mEq/L, as suggested by the American Academy of Pediatrics 1. When it comes to replacing sodium, the goal is to replenish lost electrolytes while minimizing the risk of dehydration and other complications.

• The use of ORS is supported by multiple studies, including a meta-analysis of 17 RCTs involving 1811 patients aged <18 years from high-income and low-income countries, which found no important clinical differences in failure to rehydrate, weight gain at discharge, hyponatremia or hypernatremia, duration of diarrhea, or total fluid intake at 6 or 24 hours between children receiving ORS and IVT 1.
• A more recent study published in 2022 suggests that patients with short bowel syndrome may benefit from oral rehydration solutions with higher sodium content to compensate for losses and maintain hydration status 1.
• However, it is essential to note that the sodium content of ORS can vary, and some commercially available products may have lower sodium content, which may be suitable for prevention of dehydration or maintenance of hydration status 1.
• In cases of severe dehydration, intravenous rehydration may be necessary, and ORS can be used to replace ongoing losses once the patient is rehydrated 1.
• The World Health Organization recommends a hypotonic ORS with total osmolarity <250 mmol/L as first-line therapy for mild to moderate dehydration caused by diarrhea of all causes 1.
• In summary, the most effective way to replace sodium is to use an ORS with a sodium content of 75-90 mEq/L, and to follow the recommendations of a healthcare provider, as the needs of individual patients may vary 1.

From the Research

Replacing Sodium with Salt Drinks

• The use of salt drinks to replace sodium is a common practice, particularly in individuals who engage in vigorous exercise or experience diarrheal illness 2.
• According to the study published in FP essentials, oral electrolyte solutions are used widely for rehydration in diarrheal illness and to maintain hydration during vigorous exercise 2.
• The study recommends consuming fluids and a sodium-containing snack at least 4 hours before exercise, and during exercise, individuals require 200 to 800 mL/hour of liquid that should contain 20 to 30 mEq/L of sodium 2.

Sodium Disorders and Treatment

• Sodium disorders, such as hyponatremia and hypernatremia, can be associated with poor outcomes, and treatment is based on the underlying cause and symptoms 3, 4, 5.
• Hyponatremia can be treated with fluid restriction, isotonic saline, or diuresis, depending on the volume status of the patient 3, 4, 5.
• Hypernatremia is treated by correcting the underlying cause and correcting the free water deficit 3, 4, 5.

Sodium Intake and Health

• The current evidence suggests that most people consume a moderate range of dietary sodium (3 to 5 g/day), which is associated with the lowest risk of cardiovascular disease and mortality 6.
• The risk of adverse health outcomes increases when sodium intakes exceed 5 g/day or are below 3 g/day 6.
• It is reasonable to suggest a mean target of below 5 g/day in populations, while awaiting the results of large randomized controlled trials of sodium reduction on cardiovascular disease and death 6.