Pediatrics Made Simple For NLE NRE Step 1

1. Fetal Circulation (before birth)

• Lungs are not working properly before birth.
• Oxygenation of blood is done by the placenta.
• Umbilical cord has:
• 2 arteries
• 1 vein
• The umbilical vein carries about 80% oxygenated blood from placenta to fetus.

2. Important Shunts (and Adult Remnants)

1. Ductus venosus → connects umbilical vein to IVC → becomes ligamentum venosum.
2. Foramen ovale → shunts blood RA → LA → becomes fossa ovalis.
3. Ductus arteriosus → connects pulmonary artery to aorta → becomes ligamentum arteriosum.

congenital heart diseaes

1. Acyanotic Heart Diseases (L → R Shunt, “Pink Babies”)

General Features

• Blood flow: Left → Right shunt → mixing of oxygenated with deoxygenated blood.
• Symptoms: May appear late.
• Complication: Backward reversal of shunt → Eisenmenger syndrome (cyanosis develops).

1. Patent Ductus Arteriosus (PDA)

Causes:

• Maternal rubella infection
• Maternal ↑ prostaglandins

Auscultation: Machine-like murmur

Pulse: Wide pulse pressure

Management:

• Indomethacin → closes duct
• Prostaglandins (PGE1) → keep it open
• If not closed by 8 months → surgery

Special note: PDA must not be closed in TOF and TGA (cyanotic CHD).

2. Atrial Septal Defect (ASD)

• Shunt: Left → Right
• Auscultation: Wide, fixed splitting of S2

3. Ventricular Septal Defect (VSD)

• Shunt: Left → Right
• CXR: Cardiomegaly, delayed closure of pulmonary valve
• Complications: Pulmonary arterial hypertension (PAH)
• Association: Down syndrome
• Investigation of choice: Echocardiography
• Types:
  1. Restrictive VSD → often closes spontaneously
  2. Non-restrictive VSD → symptoms: fatigue, poor growth, failure to thrive, malaise
     • Auscultation: Harsh holosystolic murmur
     • Treatment: Surgical closure

2. Cyanotic Heart Disease

Tetralogy of Fallot (TOF)

Mnemonic – PROV

• P → Pulmonary stenosis / Pulmonary hypertension
• R → Right ventricular hypertrophy (RVH)
• O → Overriding of aorta
• V → Ventricular septal defect (VSD)

Most common cyanotic CHD in children

Clinical features

• Usually presents at 8–14 years
• Dyspnea
• Bluish discoloration (cyanosis)
• Squatting → increases systemic vascular resistance → improves oxygenation

Investigations

• X-ray: Boot-shaped heart
• ECG: RVH + Cardiomegaly

Treatment

Definitive: Surgical repair

Here are other materials for NLE NRE step 1

1. CHD Associations with Conditions

• Fetal alcohol syndrome → VSD
• Infant of diabetic mother → Transposition of great vessels (TGV)
• Turner syndrome → Coarctation of aorta
• Congenital rubella → PDA
• Congenital lupus → Congenital heart block
• Kawasaki disease → Coronary artery aneurysm

2. Classic X-ray Appearances

• TOF → Boot-shaped heart
• TGV → Egg-on-a-string (Egg shell)

3. Congenital Heart Diseases – Murmurs & Sounds

3. Coarctation of Aorta

Narrowing of the aorta → ↑ blood flow in upper extremities & ↓ flow in lower extremities

Types

Clinical Features

• Upper extremities: Hypertension, redness
• Lower extremities: Hypotension, cyanosis, poor growth, failure to thrive

Blood Pressure:

• ↑ SBP in arms
• ↓ SBP in legs

Pulse: Radio-femoral (radio-temporal) delay

Investigations

• CXR
• Echo with color Doppler (diagnosis of choice)

Management

• PGE1 infusion → keep ductus arteriosus open (in infants)
• Balloon angioplasty → definitive treatment

4. Chromosomal disorder

5. Double Y Chromosome (47,XYY)

Karyotype: 47,XYY

Cause: Meiotic nondisjunction (usually paternal)

Clinical Features:

• Normal height and physical development
• Frequent anger / aggressive behavior
• Severe acne
• May have mild learning difficulties

Management: Supportive care, behavioral counseling if needed

6. Hypertrophic Pyloric Stenosis

• Definition: Hypertrophy and narrowing of the pyloric sphincter → delayed gastric emptying
• Risk Factors:
  • Exact cause unknown
  • Maternal erythromycin exposure
• Clinical Features:
  • Non-bilious projectile vomiting (classic)
  • Infant remains hungry after vomiting (“hungry vomiter”)
  • Signs of dehydration
• Examination:
  • Abdominal distension
  • Olive-shaped, mobile, non-tender mass in epigastrium
• Investigations:
  • Metabolic alkalosis (hypochloremic, hypokalemic)
  • Barium swallow → “string sign”
• Treatment:
  • Initial: NPO (nil per oral), IV fluids, correct electrolytes
  • Definitive: Surgical pylorotomy

7. Intussusception

• Proximal intestine telescopes into distal part → bowel obstruction
• Age group: 6 months – 3 years
• Epidemiology: More common in boys
• Clinical Triad:
  • Intermittent abdominal pain
  • Bloody diarrhea (“red currant jelly stools”)
  • Vomiting
• Investigations:
  • USG abdomen: “Target sign / Doughnut sign” at site of pain
  • ABG: Metabolic alkalosis (due to vomiting)
• Treatment:
  • Initial: Air or barium enema (diagnostic + therapeutic)
  • Surgery if enema fails or perforation is suspected

8. Meckel’s Diverticulum

• Failure of omphalomesenteric (vitelline) duct to obliterate → true diverticulum
• Epidemiology: More common in males
• Rule of 2’s:
  • 2% of population
  • 2 times more common in boys
  • 2 inches in length
  • 2 feet from ileocecal valve
  • 2 types of ectopic mucosa (gastric & pancreatic)
  • Symptoms before 2 years of age
• Clinical Features:
  • Often asymptomatic
  • Painless hematochezia (classic)
  • Pallor, shortness of breath due to anemia
• Investigations:
  • Technetium-99m pertechnetate scan → detects ectopic gastric mucosa
• Treatment: Surgical resection

9. Hirschsprung Disease

• Absence of ganglion cells in the intestinal wall (neural crest cell migration defect) → no peristalsis in affected segment.
• Epidemiology / Risk Factors:
  • Male > Female
  • Premature infants
  • Associated with Down syndrome

Clinical Features

• Delayed passage of meconium (>48 hours after birth)
• Bilious vomiting
• Abdominal distention
• Failure to thrive

Examination

• DRE: Explosive discharge of stool & gas → squirt sign

Diagnosis

• Gold standard: Rectal biopsy → absence of ganglion cells
• Supportive: Contrast enema showing transition zone

Treatment

• Surgical resection of aganglionic segment (pull-through procedure)

Key Differentiation in Delayed Meconium

• If respiratory symptoms present → think Cystic Fibrosis
• If no respiratory symptoms:
  • DRE → gush of stool → Hirschsprung disease
  • DRE → no stool → Other intestinal obstruction (e.g., ileal atresia, meconium ileus in CF)

10. Cystic Fibrosis (CF)

• Genetics:
  • Autosomal recessive
  • Mutation in CFTR gene (Chromosome 7)

Clinical Features

• Respiratory:
  • Chronic cough, recurrent lung infections
  • Wheeze, bronchiectasis
  • Salty-tasting skin (due to high NaCl in sweat)
• Gastrointestinal:
  • Pancreatic insufficiency → malabsorption, steatorrhea, FTT (failure to thrive)
  • Delayed passage of meconium (meconium ileus) in neonates
• Other:
  • Male infertility (absence of vas deferens)

Diagnosis

• Sweat chloride test: > 60 mmol/L = diagnostic
• Genetic testing for CFTR mutation (confirmatory)

Treatment

• Nutritional:
  • High-calorie, high-protein diet
  • Supplement fat-soluble vitamins (A, D, E, K)
• Pulmonary:
  • Bronchodilators
  • Anti-inflammatory drugs
  • Antibiotics (for recurrent infections)
  • Chest physiotherapy
  • Oxygen supplementation in advanced disease

11. Kawasaki Disease

A multi-segment, medium-vessel vasculitis, primarily affecting children < 5 years. Considered an autoimmune phenomenon.

Phases

1. Acute phase (1–2 weeks):
   • High fever > 5 days
   • Rash, conjunctivitis, strawberry tongue, lymphadenopathy, extremity changes
   • ↑ Risk of myocarditis
2. Subacute phase (2–8 weeks):
   • Desquamation (peeling of skin on fingers/toes)
   • ↑ Risk of coronary artery aneurysm
3. Chronic phase:
   • Gradual resolution of symptoms
   • ESR and CRP return to normal

Clinical Features (Mnemonic: CRASH & Burn)

• Conjunctivitis (bilateral, non-purulent)
• Rash (polymorphous)
• Adenopathy (cervical, usually unilateral)
• Strawberry tongue + mucosal changes (red, cracked lips)
• Hand and feet changes (edema, erythema, peeling)
• Burn: Fever > 5 days

Treatment

• High-dose Aspirin (anti-inflammatory, antipyretic, antiplatelet)
• IVIG (prevents coronary aneurysm if given early)
• Low-dose Aspirin (continued up to 6 weeks or longer if coronary involvement persists)
• Corticosteroids (for refractory disease)

12. Juvenile Idiopathic Arthritis (JIA)

• Autoimmune disease → joint inflammation
• Morning stiffness + gradual loss of movement
• Symptoms last ≥ 6 weeks
• Age: < 16 years

Types

13. Acute Otitis Media (AOM)

Inflammation of the middle ear cavity.

Causes:

• Bacterial: Streptococcus pneumoniae, Haemophilus influenzae
• Viral: Measles, Influenza, RSV
• Non-infectious: Allergy

Clinical Features:

• Otalgia (ear pain)
• Fever
• Excessive crying
• Difficulty sleeping

Otoscopic Findings:

• Erythematous tympanic membrane (TM)
• Bulging or retraction of TM
• Decreased TM mobility

Treatment:

• First line: Co-amoxiclav

Complications (if untreated):

• Mastoiditis
• TM perforation → conductive hearing loss
• Meningitis
• Chronic suppurative otitis media (CSOM)

14. Bronchiolitis

Inflammation of small airways, usually in children < 2 years.

Cause:

• Most common: Respiratory Syncytial Virus (RSV)

Clinical Features:

• Cough
• Dyspnea, shortness of breath
• Chest tightness
• Auscultation: “Washing machine wheeze”

Treatment:

• Primarily supportive care
• Resistant/severe cases: Palivizumab, Ribavirin

15. Meningitis

Causes (Age-wise):

• Neonates: Group B Streptococcus (Streptococcus agalactiae)
• Infants: Streptococcus pneumoniae
• Adolescents (14–18 yrs): Neisseria meningitidis
• Middle age adults: Streptococcus pneumoniae
• Viral: HSV (Herpes Simplex Virus)
• Fungal: Cryptococcus neoformans

Clinical Signs:

• Kernig’s sign (+)
• Brudzinski’s sign (+)

Treatment:

• Ampicillin + Cefotaxime