✅ Model Answer:
• Prominent perihilar vascular markings (pulmonary plethora).
• Fluid in interlobar fissures – especially the right horizontal fissure.
• Mild cardiomegaly (enlarged cardiac silhouette).
• Small bilateral pleural effusions.
• Clear lung fields – no ground-glass opacities.
• Diagnosis: Transient Tachypnea of Newborn (TTN).

✅ Model Answer:
• TTN results from delayed clearance of fetal lung fluid.
• During normal vaginal delivery, the thoracic squeeze and catecholamine surge (epinephrine, cortisol) activate ENaC (epithelial sodium channels) → lung fluid absorption.
• In elective C-section without labor, these mechanisms are absent → lung fluid remains → impaired gas exchange → tachypnoea.
• The fluid accumulates in the pulmonary interstitium, perihilar regions, and interlobar fissures.
• Risk factors: Elective C-section, late preterm, maternal diabetes, maternal asthma, male sex.

✅ Model Answer:
• Onset: Within the first 2-4 hours of life.
• Tachypnoea – respiratory rate >60 breaths/min (often 80-100).
• Mild subcostal retractions, expiratory grunting (mild), nasal flaring.
• Cyanosis is uncommon – usually pink in room air (SpO2 90-95%).
• Clear breath sounds – no crackles (unlike RDS).
• Self-limited: Symptoms peak at 12-24 hours, resolve by 24-72 hours.
• Infant is otherwise well – normal activity, normal feeding.
• Chest X-ray findings as described above.

✅ Model Answer:
• Supportive care:
- Supplemental oxygen – if SpO2 <90%, use nasal cannula or hood oxygen to maintain SpO2 90-95%.
- Nasal CPAP – for moderate to severe tachypnoea (or if FiO2 >0.4).
- NPO with IV fluids – if tachypnoea prevents feeding (risk of aspiration).
- Maintain neutral thermal environment – to reduce metabolic stress.
• Monitor: SpO2, respiratory rate, work of breathing.
• Exclude sepsis: Blood culture, CRP, CBC – if risk factors for infection.
• Do NOT use: Surfactant (not indicated – TTN is not surfactant deficiency).
• Duration: Symptoms resolve in 24-72 hours; often discharge by day 3-4.

✅ Model Answer:

Feature	TTN	RDS
Gestational age	Term / late preterm	Preterm (<34 weeks)
Risk factor	Elective C-section	Surfactant deficiency
CXR	Perihilar streaking, fluid in fissures	Ground-glass opacities, air bronchograms
Lung volumes	Normal	Decreased (atelectasis)
Onset	First 2-4 hours	Immediately or first hours
Duration	24-72 hours (self-limited)	Days to weeks
Treatment	Supportive, O₂, CPAP	Surfactant, CPAP/ventilation

✅ Model Answer:
• Role of CPAP: Provides continuous positive airway pressure to splint open alveoli, improve oxygenation, and reduce work of breathing.
• Indications:
- Moderate to severe tachypnoea with increased work of breathing.
- FiO2 requirement >0.4 to maintain SpO2 >90%.
- Signs of respiratory distress (retractions, grunting).
- To avoid intubation/ventilation.
• Settings: CPAP 5-8 cm H2O.
• Duration: Usually 12-48 hours; wean as symptoms improve.
• Note: CPAP is supportive; TTN resolves spontaneously as lung fluid clears.

✅ Model Answer:
• Respiratory Distress Syndrome (RDS): Preterm, surfactant deficiency, ground-glass CXR.
• Transient Tachypnea of Newborn (TTN): Term, elective C-section, perihilar streaking, self-limited.
• Meconium Aspiration Syndrome (MAS): Post-term, meconium-stained fluid, patchy infiltrates, hyperinflation.
• Sepsis / Pneumonia: Maternal fever, prolonged ROM, leukocytosis, patchy infiltrates, clinically ill.
• Congenital pneumonia: Group B Streptococcus, chest X-ray with diffuse opacities.
• Congenital heart disease: Cyanotic heart disease (TGA, TOF), cardiomegaly, decreased pulmonary vascularity.
• Persistent Pulmonary Hypertension of Newborn (PPHN): Cyanosis, differential cyanosis, echocardiogram needed.
• Pneumothorax: Sudden deterioration, hyperlucency, mediastinal shift.

✅ Model Answer:
• Diagnosis: Transient Tachypnea of Newborn (TTN).
• Management:
1. Supportive care: Oxygen if SpO2 <90% (nasal cannula/hood).
2. NPO with IV fluids if tachypnoeic (risk of aspiration).
3. Monitor SpO2, respiratory rate, work of breathing.
4. Blood culture and CRP to exclude sepsis (if risk factors).
5. CPAP if moderate-severe distress or FiO2 >0.4.
6. Reassure parents: TTN is self-limited (resolves in 24-72 hours).
7. Discharge when respiratory rate normalizes and feeding is established.

✅ Model Answer:
• Excellent prognosis – TTN is a self-limited condition.
• Symptoms resolve in 24-72 hours.
• No long-term respiratory sequelae.
• Infants do not require follow-up for TTN once resolved.
• However, if symptoms persist >72 hours, consider alternative diagnoses (sepsis, pneumonia, congenital heart disease).
• TTN is a benign condition and does not increase the risk of chronic lung disease or asthma.

✅ Model Answer:
• This is TTN with moderate respiratory distress.
• Next steps:
1. Nasal CPAP – 5-8 cm H2O to support oxygenation and reduce work of breathing.
2. If CPAP fails (FiO2 >0.6, worsening distress), consider intubation and mechanical ventilation (rare in TTN).
3. Exclude sepsis: Blood culture, CRP, CBC, lumbar puncture if indicated.
4. Echocardiogram: To rule out congenital heart disease if hypoxia is persistent.
5. Monitor: SpO2, respiratory rate, ABG if needed.
6. Wean oxygen and CPAP as symptoms improve.

✅ Model Answer:
• TTN typically resolves by 72 hours. Worsening at 48 hours is atypical.
• Consider alternative diagnoses:
1. Sepsis / Pneumonia – Group B Streptococcus, E. coli – check blood culture, CRP, chest X-ray.
2. Congenital heart disease – cyanotic heart disease, duct-dependent lesion – echocardiogram.
3. Meconium aspiration syndrome – if meconium-stained fluid was present.
4. Congenital diaphragmatic hernia – bowel loops in chest on CXR.
5. Pulmonary hypertension (PPHN) – echocardiogram to assess PA pressure.
6. Air leak syndrome – pneumothorax, pneumomediastinum.
7. Metabolic disorders – if acidosis is present.

✅ Model Answer:
• Chest X-ray is the most important imaging tool to differentiate TTN from RDS.
• TTN findings: Perihilar streaking, fluid in interlobar fissures (especially right horizontal fissure), mild cardiomegaly, small pleural effusions.
• RDS findings: Ground-glass opacities (homogeneous), air bronchograms, decreased lung volumes (atelectasis).
• Key differentiator: TTN has clear lung fields with prominent markings; RDS has diffuse haziness and air bronchograms.
• Clinical correlation: Term infant, elective C-section + TTN CXR = TTN. Preterm infant, surfactant deficiency + RDS CXR = RDS.