Hyponatremic Dehydration (Na <130 mEq/L)

Here you calculate sodium deficit explicitly:Na⁺ deficit (mEq)=(135−Serum Na)×0.6×weight (kg)\textbf{Na⁺ deficit (mEq)} = (135 – \text{Serum Na}) \times 0.6 \times \text{weight (kg)}Na⁺ deficit (mEq)=(135−Serum Na)×0.6×weight (kg)

👉 135 mEq/L is taken as desired Na

Example

10 kg child, Na = 125 mEq/L(135−125)×0.6×10=10×6=60 mEq(135 – 125) \times 0.6 \times 10 = 10 \times 6 = \textbf{60 mEq}(135−125)×0.6×10=10×6=60 mEq

Important

• Correct slowly over 24–48 hrs
• Max rise: ≤8–10 mEq/L/day
• Give via DNS / NS + added Na as needed

Isonatremic Dehydration (Na 130–150)

No sodium deficit calculation needed

Instead calculate:

• Fluid deficit = % dehydration × weight × 10

Example:

• 10% dehydration in 10 kg child →
  = 10 × 10 × 10 = 1000 mL deficit

Give:

• Deficit + maintenance + ongoing loss
• Usually NS / RL initially

Hypernatremic Dehydration (Na >150)

👉 Do NOT calculate sodium deficit
Instead calculate free water deficit:Water deficit (L)=0.6×wt×(Na145−1)\textbf{Water deficit (L)} = 0.6 \times \text{wt} \times \left(\frac{\text{Na}}{145} – 1\right)Water deficit (L)=0.6×wt×(145Na​−1)

Example

10 kg child, Na = 1600.6×10×(160/145−1)≈6×0.103=0.62 L0.6 \times 10 \times (160/145 – 1) \approx 6 \times 0.103 = \textbf{0.62 L}0.6×10×(160/145−1)≈6×0.103=0.62 L

Key Pediatric Pearls (Exam Gold)

• Hyponatremia → calculate Na deficit
• Hypernatremia → calculate water deficit
• Isonatremia → calculate fluid deficit only

Correction Rules

• Hyponatremia: ↑ Na ≤8 mEq/day
• Hypernatremia: ↓ Na ≤10–12 mEq/day
• Rapid correction → ODS (hypo) / cerebral edema (hyper)

First principle:
👉 Most overweight infants are exogenous (overfeeding).
👉 Investigations are needed only if there are red flags for endocrine, genetic, or metabolic causes.

1️⃣ Step 1: Confirm Overweight / Obesity

Anthropometry

• Weight-for-length (WHO growth charts)
• BMI (if >2 years; not for infants)
• Head circumference
• Mid-upper arm circumference (optional)

Definitions (WHO)

• > +2 SD weight-for-length → Overweight
• > +3 SD → Obese

2️⃣ When to Investigate?

Send investigations if:

• Rapid weight gain
• Short length/height (↓ linear growth)
• Dysmorphic features
• Developmental delay
• Hypotonia
• Organomegaly
• Hyperphagia
• Family history of endocrine/genetic disorders
• Signs of hypothyroidism, Cushing, etc.

If thriving, normal length, normal development → usually no labs required.

3️⃣ Baseline Investigations (If Indicated)

4️⃣ Endocrine Causes to Rule Out

A. Hypothyroidism

• TSH
• Free T4

Clues:

• Constipation
• Large tongue
• Hypotonia
• Poor linear growth

B. Cushing Syndrome (Very Rare in Infants)

• 8 AM cortisol
• Low-dose dexamethasone suppression test (if needed)

Clues:

• Moon face
• Hypertension
• Growth failure
• Thin skin

C. Hyperinsulinism

• Fasting insulin
• Blood glucose

5️⃣ Genetic / Syndromic Evaluation

If:

• Hypotonia
• Developmental delay
• Dysmorphism
• Hyperphagia

Consider:

• Karyotype
• Microarray
• Referral to genetics

Examples:

• Prader-Willi syndrome
• Beckwith-Wiedemann syndrome

6️⃣ Metabolic Screening (If Suspicion)

If:

• Hepatomegaly
• Hypoglycemia
• Recurrent vomiting
• Developmental delay

Send:

• Serum ammonia
• Lactate
• Tandem mass spectrometry
• Urine organic acids

7️⃣ If Severe Obesity (> +3 SD)

Consider screening for:

• Lipid profile
• LFT (NAFLD)
• Blood pressure monitoring
• HbA1c (if strong suspicion)

8️⃣ What NOT to Routinely Send

❌ Insulin levels in every overweight baby
❌ Extensive metabolic panels without red flags
❌ Hormone panels without growth failure

9️⃣ Practical Clinical Algorithm (Exam-Friendly)

Normal length + normal development + formula overfeeding → NO LABS

Overweight + short length → TSH + Free T4

Overweight + hypotonia + hyperphagia → genetic workup

Overweight + moon face + hypertension → cortisol evaluation

🔟 For Your Clinical Practice in Nepal

In most cases in our setup:

• It is formula concentration error or early complementary feeding.
• Counseling on feeding practice is more important than investigations.

Perforated Acute Otitis Media (AOM with tympanic membrane perforation) is treated slightly differently from uncomplicated AOM because the perforation allows topical therapy to reach the middle ear.

1. First-line Treatment

A. Topical Antibiotic Ear Drops (Most Important)

Use quinolone ear drops because they are safe in perforated TM.

• Ofloxacin ear drops
  • Dose: 5 drops in affected ear twice daily
  • Duration: 7–10 days

OR

• Ciprofloxacin ear drops
  • Dose: 4–5 drops twice daily
  • Duration: 7–10 days

Avoid aminoglycoside drops (e.g., Gentamicin, Neomycin) because they can be ototoxic if TM is perforated.

2. Oral Antibiotics (if indicated)

Give systemic antibiotics if:

• Moderate/severe infection
• Fever
• Young child (<2 years)
• Bilateral disease
• Systemic symptoms

First line:

• Amoxicillin
  • 80–90 mg/kg/day divided BID
  • Duration 7–10 days

If severe infection or recent amoxicillin use:

• Amoxicillin‑clavulanate
  • 90 mg/kg/day (amoxicillin component)

3. Analgesics

• Paracetamol 10–15 mg/kg every 6 hours
  OR
• Ibuprofen 10 mg/kg every 8 hours

4. Local Care

• Keep ear dry (no water entry).
• Do not plug ear tightly.
• Gentle ear toilet/suction if discharge excessive.

5. Follow-up

• Re-examine after 1–2 weeks.
• Most perforations heal spontaneously within 2–4 weeks.
• If persistent perforation >6 weeks → ENT referral.

6. Red Flags (Refer ENT)

• Persistent otorrhea >2 weeks
• Suspected mastoiditis
• Hearing loss
• Recurrent perforations

Example Pediatric Prescription

• Ofloxacin ear drops: 5 drops BD × 7 days
• Amoxicillin: 80–90 mg/kg/day divided BD × 7 days
• Paracetamol: 10–15 mg/kg every 6 hr PRN pain