8.3 Pediatric Diarrhoea, Dehydration & Respiratory Emergencies

Pediatric Diarrhea & Dehydration Management

Diarrheal disease remains a leading cause of pediatric mortality under 5 years, primarily due to acute hypovolemic shock and electrolyte imbalance.

Pathophysiology of Diarrhea

• Secretory Diarrhea: Triggered by enterotoxins (e.g., Vibrio cholerae, Enterotoxigenic E. coli - ETEC) that activate intracellular cAMP/cGMP, causing active secretion of chloride and water into lumen without mucosal damage. Stool persists during fasting.
• Osmotic Diarrhea: Caused by unabsorbed solutes or mucosal villous tip damage (e.g., Rotavirus infection leading to lactase deficiency). Unabsorbed sugars draw water into the intestinal lumen. Diarrhea stops upon fasting.
• Invasive / Dysenteric Diarrhea: Direct mucosal invasion by pathogens (Shigella, Enteroinvasive E. coli, Entamoeba histolytica) resulting in mucosal ulceration, bloody stool with mucus, and systemic inflammatory response.

---

WHO Clinical Assessment of Dehydration

To determine the fluid management protocol, assess four core clinical signs:

---

Low-Osmolarity Oral Rehydration Solution (ORS)

The current WHO/UNICEF recommended Low-Osmolarity ORS has a total osmolarity of 245 mOsm/L (reduced from the older 311 mOsm/L formula to prevent hyperosmolar gut loading).

Composition of Low-Osmolarity ORS (Per Liter of Clean Water)

• Sodium: 75 mmol/L (Sodium Chloride 2.6 g/L)
• Glucose (Anhydrous): 75 mmol/L (Glucose 13.5 g/L)
• Potassium: 20 mmol/L (Potassium Chloride 1.5 g/L)
• Chloride: 65 mmol/L
• Trisodium Citrate: 10 mmol/L (Trisodium Citrate Dihydrate 2.9 g/L)
• Total Osmolarity: 245 mOsm/L

Physiological Principle: The 1:1 equimolar ratio of Sodium (75 mmol/L) and Glucose (75 mmol/L) optimizes the coupled Sodium-Glucose Cotransporter 1 (SGLT-1) at the intestinal brush border membrane. As sodium and glucose are co-transported into enterocytes, water follows passively across the osmotic gradient, even during active toxin-induced secretory diarrhea.

---

WHO Treatment Protocols: Plan A, B, and C

WHO Plan A: Home Management (Prevent Dehydration)

1. Give Extra Fluids: ORS, rice water, buttermilk (chaach), soup, or clean water after every loose stool.
   • Age < 2 years: 50–100 mL after each stool.
   • Age 2–10 years: 100–200 mL after each stool.
2. Zinc Supplementation: Administer elemental Zinc daily for 14 days (reduces duration, severity, and 3-month recurrence).
   • Age < 6 months: 10 mg/day
   • Age ≥ 6 months: 20 mg/day
3. Continue Feeding: Continue frequent breastfeeding and energy-dense soft foods. Do NOT restrict food.
4. Mother Education: Return immediately if child develops danger signs (unable to drink, worsening diarrhea, persistent vomiting, fever, blood in stool).

WHO Plan B: Management of Some Dehydration

• Administer Low-Osmolarity ORS over a 4-hour period in a health facility.
• Target Volume: Weight (in kg) × 75 mL (e.g., a 10 kg child receives 750 mL ORS over 4 hours).
• If child vomits, wait 10 minutes, then resume ORS more slowly (spoonful every 2–3 minutes).
• Reassess dehydration status after 4 hours. If signs clear → Switch to Plan A; if Some Dehydration persists → Repeat Plan B; if progressing to Severe Dehydration → Switch to Plan C.

WHO Plan C: Management of Severe Dehydration (Emergency IV Regimen)

• Fluid of Choice: Ringer's Lactate (RL) (or 0.9% Normal Saline if RL is unavailable). Do NOT use 5% Dextrose alone!
• Total IV Volume: 100 mL/kg divided into two phases based on age:

Reassess patient every 15–30 minutes. As soon as the child can drink (usually after 3–4 hours in infants or 1 hour in older children), give oral ORS at 5 mL/kg/hr alongside IV therapy.

Pediatric Respiratory Emergencies & IMNCI Guidelines

Acute Respiratory Infections (ARI) represent a primary emergency in pediatric practice. The Integrated Management of Neonatal and Childhood Illness (IMNCI) protocol provides rapid field triage for pneumonia.

IMNCI Assessment & Triage of Pneumonia

Fast Breathing Cutoff Thresholds (Count RR for 1 Full Minute in Calm Child)

• Age < 2 Months: ≥ 60 breaths / minute (Automatically classified as Severe Disease / Pneumonia)
• Age 2 to 11 Months: ≥ 50 breaths / minute
• Age 12 to 59 Months: ≥ 40 breaths / minute

IMNCI Diagnostic Framework

1. No Pneumonia (Cough or Cold):
   • Signs: No fast breathing, no chest indrawing.
   • Treatment: Home care, soothing throat remedies, advice on danger signs.
2. Pneumonia:
   • Signs: Fast breathing OR Chest Indrawing (lower chest wall infalling during inspiration) WITHOUT General Danger Signs.
   • Treatment: Outpatient oral Amoxicillin (45 mg/kg/day divided BD for 5 days; or updated WHO dose 80 mg/kg/day), home care, follow-up in 48 hours.
3. Severe Pneumonia / Very Severe Disease:
   • Signs: ANY General Danger Sign (Unable to drink/breastfeed, Persistent vomiting, Convulsions during current illness, Lethargic or unconscious) OR Stridor in a calm child OR Severe Central Cyanosis.
   • Treatment: Immediate hospital admission, first dose of IV/IM Ampicillin (50 mg/kg) + Gentamicin (7.5 mg/kg) or IV Ceftriaxone (50–100 mg/kg/day), supplemental humidified Oxygen (keep SpO2 > 92%), and urgent referral.

---

Upper & Lower Airway Emergencies Comparison

---

Critical Diagnostic & Therapeutic Nuances

1. Acute Epiglottitis Airway Warning

• CONTRAINDICATION: Do NOT perform direct throat examination, tongue blade depression, or aggressive pharyngeal swab in a child with suspected Epiglottitis! Direct instrumentation can provoke sudden, fatal laryngospasm and complete upper airway occlusion.
• Definitive management requires securing the airway via endotracheal intubation under general anesthesia in the operating room, followed by IV Ceftriaxone (75–100 mg/kg/day).

2. Croup Management (Westley Score)

• Mild croup (no stridor at rest): Single dose oral Dexamethasone (0.6 mg/kg, max 16 mg).
• Moderate-to-severe croup (stridor at rest, retractions): Nebulized racemic or L-Epinephrine 1:1000 (0.5 mL/kg, max 5 mL) alongside Dexamethasone. Epinephrine acts rapidly via alpha-1 adrenergic vascular constriction, shrinking subglottic mucosal edema.

3. Acute Bronchiolitis in Infants

• Occurs predominantly in infants aged 2 to 6 months during winter months.
• Characterized by necrosis of airway respiratory epithelium and mucus plugging of small bronchioles.
• Systemic corticosteroids and bronchodilators are NOT routinely recommended by AAP/IAP guidelines unless a positive asthma response is established. Mainstay is hydration and oxygenation.