A 22-month-old girl from urban Delhi presents with acute watery diarrhea for 2 days (6–7 stools per day), minimal vomiting, and normal urine output. On examination, she is alert and playful, with slightly decreased skin turgor (recoil <2 seconds) and normal mucous membranes. Weight loss is estimated at 5–6%. Serum electrolytes: sodium 138 mEq/L, potassium 3.8 mEq/L, chloride 102 mEq/L, bicarbonate 20 mEq/L. What is the most appropriate rehydration strategy?

Explanation

## Clinical Assessment This child presents with **mild-to-moderate dehydration** (5–6% weight loss, slightly decreased skin turgor, alert, normal urine output) with **isotonic dehydration** (Na 138 mEq/L, normal electrolytes, normal pH). **Key Point:** Mild-to-moderate dehydration with intact perfusion, normal mental status, and preserved urine output is best managed with **oral rehydration therapy (ORT)**, which is the WHO gold standard for non-severe diarrhea. ## Oral Rehydration Therapy (ORT) Principles ### Composition & Mechanism - **Low-osmolarity ORS** (75 mmol/L sodium, 75 mmol/L glucose) enhances sodium-glucose co-transport in the small intestine - Reduces stool output by ~30% vs. standard ORS (90 mmol/L sodium) - Reduces hypernatremia risk - Absorption continues even during active diarrhea ### Dosing & Continuation - **Maintenance + deficit replacement:** 50–100 mL/kg over 4 hours (or 5 mL/kg per stool + 2 mL/kg per vomit) - **Continue breastfeeding** (if applicable) and age-appropriate foods (no fasting) - Reassess hydration status every 2–4 hours **High-Yield:** ORT has >90% success rate in mild-to-moderate dehydration; IV therapy is reserved for severe dehydration, persistent vomiting, or inability to drink. **Clinical Pearl:** Continuing age-appropriate foods (rice, bread, potatoes, yogurt) during diarrhea reduces stool output, shortens illness duration, and improves nutritional recovery—a paradigm shift from the older "bowel rest" approach. ## Why This Answer Option 1 (low-osmolarity ORS + continued feeding) is correct because: 1. Child meets criteria for mild-to-moderate dehydration (5–6% loss, alert, normal perfusion). 2. Isotonic dehydration with normal electrolytes—ORS is safe and effective. 3. Continued breastfeeding and foods reduce stool output and promote recovery. 4. IV therapy is unnecessary and carries risks (line infection, hyperchloremic acidosis with normal saline). ```mermaid flowchart TD A["Acute diarrhea + dehydration"]:::outcome --> B{"Severity of dehydration?"}:::decision B -->|"Mild-Moderate<br/>(5-10% loss)<br/>Alert, normal perfusion"| C["Oral Rehydration Therapy"]:::action B -->|"Severe<br/>(>10% loss)<br/>Shock signs, oliguria"| D["IV Rehydration<br/>0.9% NaCl bolus"]:::action C --> E["Low-osmolarity ORS<br/>75 mmol/L Na+"]:::action E --> F["Continue breastfeeding<br/>+ age-appropriate foods"]:::action F --> G["Reassess q2-4h"]:::action G --> H{"Improving?"}:::decision H -->|"Yes"| I["Maintenance therapy"]:::outcome H -->|"No or worsening"| J["Switch to IV therapy"]:::action ``` **Mnemonic:** **ORT FIRST** — **O**ral rehydration is first-line for mild-to-moderate diarrhea, **R**educes stool output, **T**reats electrolyte loss. **F**ood & fluids continue, **I**V only if severe, **R**eassess regularly, **S**upport nutrition, **T**reat underlying cause.