PPHN INV IN NN

Table 57.1 Investigations and their rationale for infants suspected to have persistent pulmonary hypertension of the newborn
(PPHN).
Investigations Rationale
Blood – standard Blood culture, C-reactive protein Screen for sepsis
Complete blood count, blood group Rule out anemia, hypoglycemia, electrolyte
Blood glucose, electrolytes disturbances
Serum lactate Evaluate systemic perfusion
ABG Rule out acidosis, hypercarbia
Blood – special
cases
ABG with hyperoxia test Screen for critical cyanotic heart defect
Liver, renal function tests
Coagulation screen (INR, PT, APTT)
Serum ammonia
Evaluate for end-organ dysfunction (e.g., in sepsis,
asphyxia)
Rule out coagulopathy
Metabolic screen
Genetic testing Presence of dysmorphic features
Karyotyping Suspicion of familial causes (surfactant protein
Screen for specific mutations deficiency, ACD)
Table 57.1 (Continued)
Investigations Rationale
Imaging – standard Chest X-ray Position of endotracheal tube
(with nasogastric or orogastric tube in situ) Rule out pneumothorax
Parenchymal lung disease (e.g., RDS, MAS)
Structural lung defects (e.g., CDH, esophageal atresia)
Abnormal heart shape (e.g., ‘snowman’ shape in
TAPVD; narrow mediastinum with egg-shape heart in
TGA; massive cardiomegaly in Ebstein anomaly)
RVH – boot-shaped heart with apex ‘lifted’ from the
diaphragm
Abdominal X-ray Confirm position of umbilical lines
Echocardiogram Confirm diagnosis and monitor progress
Rule out CHD
Imaging – special
cases
Cranial ultrasound AVMs (vein of Galen malformation)
Evidence of brain injury
Chest CT scan Pulmonary lymphangiectasia
Pathology Lung biopsy ACD; surfactant protein deficiency