What is the role of Resomal (oral rehydration solution) and potassium in managing severe malnutrition?

Resomal and Potassium in Severe Malnutrition

In severely malnourished children with diarrhea and dehydration, use low-osmolarity WHO ORS (with supplemental potassium if needed) rather than ReSoMal, as ReSoMal carries significant risk of symptomatic hyponatremia and seizures despite better potassium correction. 1, 2

Critical Safety Concern with ReSoMal

ReSoMal (45 mmol/L sodium, 40 mmol/L potassium) was designed specifically for severe acute malnutrition to theoretically prevent sodium overload and treat severe hypokalemia 3. However:

• ReSoMal causes symptomatic hyponatremia: In controlled trials, 29% of children remained hyponatremic at 48 hours, with three children developing severe hyponatremia (one with seizures at serum sodium 108 mmol/L) 1
• The hyponatremia risk is particularly concerning because severe hyponatremia at admission is already a major risk factor for poor outcomes in malnourished children with diarrhea 3
• No trials have been conducted in African children where SAM mortality remains highest, only in Asian populations 3

Recommended Approach: Modified Low-Osmolarity ORS

Use standard low-osmolarity WHO ORS (75 mmol/L sodium, 245 mOsm) with added potassium (20 mmol/L total) for rehydration: 2

• Only 1.9% developed hyponatremia compared to 15.4% with modified ReSoMal 2
• No cases of severe hyponatremia or hypernatremia occurred 2
• Equal success rates in achieving rehydration (94.5% in both groups) 2
• Effectively corrects both dehydration and hypokalemia 2

Potassium Management Strategy

Potassium replacement is critical but must be approached systematically:

Initial Assessment

• Measure serum potassium at baseline, as hypokalemia is nearly universal in severe malnutrition with diarrhea 1, 4
• Standard WHO ORS contains only 20 mmol/L potassium, which may be inadequate for ongoing losses 5

Supplementation Protocol

• Add extra potassium to achieve 40 mmol/L total in ORS solution 1, 2
• Monitor serum potassium at 24 and 48 hours during rehydration 1, 4
• Persistent hypokalemia occurs in approximately 19% of cases even after rehydration 4

Correction Timeline

• With adequate potassium supplementation (40 mmol/L), 36% correct hypokalemia by 24 hours and 46% by 48 hours 1
• Standard WHO ORS corrects only 5% by 24 hours and 16% by 48 hours 1

Rehydration Protocol for Severe Malnutrition

Volume and rate must be carefully controlled to prevent overhydration:

• Use 5 mL/kg every 30 minutes for first 2 hours, then 5-10 mL/kg/hour for next 4-10 hours 1
• Monitor closely for periorbital edema (occurs in 25.5% of cases) 4
• Overhydration risk is 5-12% depending on solution used 1
• Constant monitoring is required throughout rehydration 4

Fluid Restriction Principles

Restrict hypotonic oral fluids to prevent worsening sodium depletion:

• Avoid plain water, tea, coffee, and alcohol as these cause net sodium loss from the gut 6
• Avoid hypertonic fluids (fruit juices, colas) which cause both sodium and water loss 6
• Encourage sipping glucose-saline ORS in small quantities throughout the day 6

Common Pitfalls to Avoid

• Never use "clear liquids" instead of proper ORS: This causes osmotic diarrhea and worsens electrolyte imbalance due to inadequate sodium/bicarbonate and excess sugar 5
• Do not overestimate dehydration severity: This occurred in 14% of cases in one series, leading to unnecessary aggressive rehydration 4
• Monitor for paralytic ileus and excessive vomiting: These complications require discontinuation of oral rehydration (occurred in 6% of cases) 4
• Recognize that serum sodium relates more to hydration status than actual sodium loss: Water loss typically exceeds proportional sodium loss 5

When to Use Parenteral Support

Switch to IV fluids if: 1, 4

• Severe dehydration (≥10% fluid deficit) with signs of shock 5
• Excessive vomiting preventing oral intake 4
• Development of paralytic ileus 4
• Failure of oral rehydration after appropriate trial 4