Master RDS, BPD, PPHN, surfactant therapy, and neonatal ventilation strategies.
90 min estimated
Neonatal RDS (also called hyaline membrane disease) results from surfactant deficiency in premature lungs. Surfactant reduces alveolar surface tension, preventing collapse at end-expiration.
Risk factors: prematurity (<36 weeks, especially <28 weeks), maternal diabetes, C-section without labor, male sex, second twin. Protective factors: antenatal corticosteroids (betamethasone 2 doses 24h apart), PROM, maternal hypertension.
Clinical signs (onset within 4β6 hours of birth): tachypnea, grunting, nasal flaring, intercostal/subcostal retractions, cyanosis. CXR: diffuse ground-glass appearance, air bronchograms, low lung volumes.
Treatment: exogenous surfactant, CPAP (first-line), mechanical ventilation if severe. Target SpO2 90β95% in premature infants.
Clinical Tip
The INSURE technique (INtubate, SURfactant, Extubate to CPAP) allows surfactant delivery while minimizing mechanical ventilation exposure.
PPHN is failure of normal postnatal pulmonary vascular resistance (PVR) reduction. PVR stays elevated, causing right-to-left shunting through the foramen ovale and ductus arteriosus, producing profound hypoxemia.
Causes: meconium aspiration syndrome (MAS), perinatal asphyxia, sepsis, idiopathic, CDH (congenital diaphragmatic hernia).
Diagnosis: differential SpO2 (pre-ductal vs post-ductal difference >10%); echocardiography confirms.
Treatment: optimize oxygenation and ventilation (avoid acidosis and hypoxia β both increase PVR); inhaled nitric oxide (iNO) 20 ppm is gold standard selective pulmonary vasodilator; sildenafil for persistent cases; ECMO for refractory PPHN.
Clinical Tip
In PPHN, the right radial artery gives pre-ductal SpO2 and the umbilical artery/left hand gives post-ductal SpO2. Difference >10% is significant.
Neonatal ventilation requires lower volumes and higher rates than adults. Key principles: avoid volutrauma (Vt 4β6 mL/kg), keep Pplat <28β30, use adequate PEEP (4β6 cmH2O).
HFOV (high-frequency oscillatory ventilation): uses very small Vts (~1β3 mL/kg) at 10β15 Hz. The mean airway pressure (MAP) controls oxygenation; amplitude (ΞP) controls CO2 removal. Ideal for RDS, air leak syndromes, PPHN as rescue.
HFJV (high-frequency jet ventilation): used primarily for PIE (pulmonary interstitial emphysema) and bronchopleural fistulas β very low Vts minimize air leak.
Apnea of prematurity: treated with caffeine citrate (first-line) and CPAP/NIPPV.
Clinical Tip
On HFOV, if CO2 is high, increase amplitude (ΞP). If oxygenation is poor, increase MAP. Remember: the oscillations you see chest-wiggling = adequate CO2 removal.
27-Week Premature Infant with RDS
27-week EGA infant born via emergency C-section. Apgar 4/6. Grunting, RR 70, retractions, SpO2 75% on 100% blowby O2. CXR shows diffuse ground-glass with air bronchograms and small lung volumes.
What is the diagnosis and what are the immediate management priorities?
RDS from surfactant deficiency. Immediate: stabilize with CPAP or intubation, administer surfactant, target SpO2 90β95%.
Classic RDS presentation: premature, early onset respiratory distress, ground-glass CXR. CPAP 5β7 cmH2O is first-line; if work of breathing is severe or FiO2 >0.4 on CPAP, intubate and give surfactant (INSURE technique preferred). Target SpO2 90β95% β avoid >96% to prevent ROP.
Respiratory Pharmacology
Master every drug an RT uses β bronchodilators, steroids, mucolytics, surfactants, and more.
Oxygen Therapy
Delivery systems, FiO2 calculations, indications, complications, and oxygen toxicity.
Mechanical Ventilation
Master ventilator modes, initial settings, troubleshooting, weaning, and complications.