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Hypertrophic Pyloric Stenosis


Step 1: View clinicals

A 4 week old male infant presents with 12 episodes of vomiting over 4 days, which progressively worsened over time and became projectile in nature. No bile or blood was present. He is always hungry and often vomits after feeds. He has been exclusively breastfed so far. He was born at term with a birth weight of 3.6kg, which is between the 50th to 75th centiles.

Step 2: Order all relevant investigations

Serum Electrolytes

Na: 137 mEq/L (133-148) K: 5.5 mEq/L (4.5-6.6) Cl : 98 mEq/L (100-115)

Full Blood Count

Hb: 11.4 g/dl (9.4-13.0) WBC: 14,200/dL (6,000-18,000) Platelets: 357,000/dL (150,00-450,000)

Pyloric Ultrasound

The pyloric muscles are thickened and the pyloric channel is elongated.

Arterial Blood Gases

PH: 7.48 (7.35 – 7.45) pCO2: 47 mmHg (35 – 45) pO2: 66 mmHg (50 - 80) HCO3: 30 mEq/L (20 – 24)

Step 3: Select appropriate management

IV Fluids
NG Tube insertion

Score: ★★☆