O50. Respiratory Problems of Newborns. Resuscitation

I. Normal Transition and Respiratory Distress

Transition at Birth

• Birth transition: placental gas exchange → pulmonary gas exchange.
• First effective breaths → lung aeration, lung-fluid clearance, surfactant action and ↓ pulmonary vascular resistance.
• Functional closure of fetal shunts: foramen ovale + ductus arteriosus as left-sided pressure rises and pulmonary flow improves.
• Failure of transition → hypoxemia, persistent pulmonary hypertension and respiratory distress.
• Key principle: effective ventilation/lung aeration is the most important intervention in neonatal resuscitation.

Signs of Respiratory Distress

• Tachypnea: respiratory rate > 60/min.
• Dyspnea signs: grunting, nasal flaring, intercostal/subcostal/sternal retractions, cyanosis, apnea, poor respiratory effort.
• Rule out important mimics: infection/sepsis, congenital heart disease, hypoglycemia/metabolic disorder and pneumothorax.
• In resuscitation: heart rate is the best indicator of response to ventilation.

II. Common Respiratory Disorders

Respiratory Distress Syndrome

• RDS: mainly preterm infant disease due to surfactant deficiency.
• Risk factors: prematurity <34 weeks, maternal diabetes, cesarean, male sex, perinatal asphyxia.
• Pathophysiology: surfactant deficiency → ↑ surface tension → alveolar collapse → ↓ compliance → hypoxemia, hypercapnia and respiratory acidosis.
• Severe disease: alveolar-capillary injury → protein-rich leak → hyaline membranes; hypoxemia may trigger PPHN.
• Clinical signs: onset within minutes-hours, tachypnea, grunting, retractions, nasal flaring, cyanosis/hypoxemia.
• Diagnosis: clinical picture + CXR ground-glass appearance; ABG may show ↓pO2, ↑pCO2 and respiratory acidosis.
• Treatment: CPAP first-line, target oxygen saturation about 90-95%, exogenous surfactant when needed, mechanical ventilation if severe.
• Complications: pneumothorax, intraventricular hemorrhage, bronchopulmonary dysplasia and circulatory failure.
• Prevention: antenatal corticosteroids when preterm birth is expected.

Transient Tachypnea of Newborn (TTN)

• TTN: delayed clearance of fetal lung fluid → interstitial edema and mild airway compression.
• TTN risk factors: cesarean without labor, late preterm birth, maternal diabetes, male sex, macrosomia.
• TTN features: tachypnea within 2-6 h, mild retractions/feeding difficulty/mild hypoxia; usually resolves in 24-72 h.
• TTN management: observation, oxygen/CPAP if needed; antibiotics only until infection is excluded when clinically necessary.

Apnea of Prematurity

• Apnea of prematurity: common in very low birth weight infants; occurs mainly during sleep.
• Definition: pause ≥20 sec or shorter pause with bradycardia, cyanosis or desaturation.
• Management: cardiorespiratory monitoring, exclude sepsis/hypoglycemia/electrolyte disorder/IVH, gentle stimulation, caffeine, CPAP/HFNC or ventilation if severe.

Meconium Aspiration Syndrome (MAS)

• MAS risk factors: fetal distress, postterm pregnancy, maternal hypertension and perinatal asphyxia.
• MAS features: meconium staining, respiratory distress, severe hypoxemia/cyanosis, hyperinflated chest; pneumothorax risk.
• MAS treatment: support oxygenation/ventilation, suction only if non-vigorous with airway obstruction, consider surfactant/lavage, inhaled nitric oxide for PPHN, ECMO if extreme.

Persistent Pulmonary Hypertension of Newborn (PPHN)

• PPHN causes: MAS, RDS, pneumonia and pulmonary hypoplasia.
• PPHN clues: severe cyanosis/hypoxemia, preductal-postductal saturation difference; diagnosis by echocardiography.
• PPHN treatment: oxygen, ventilation/HFOV, inhaled nitric oxide; ECMO for refractory severe cases.

Neonatal Pneumonia

• Neonatal pneumonia: early-onset pathogens include GBS, E. coli and Listeria; risk rises with PROM, chorioamnionitis and maternal fever.
• Pneumonia diagnosis/treatment: nonspecific distress + inflammatory markers/culture/CXR; empiric ampicillin + gentamicin and respiratory support.

III. Apgar Score and Immediate Assessment

Apgar Score

• Assessed at 1 and 5 minutes; repeat later if low.
• Items: Appearance, Pulse, Grimace, Activity, Respiration; each 0-2 points, maximum 10.
• 7-10 = normal transition; <7 = abnormal and needs further evaluation/support.
• Apgar describes condition and response; it does not decide when resuscitation starts.

Routine Transitional Care

• Use the same immediate newborn-care logic as O48: warmth, wipe if obstructed, wait/delayed cord clamping, watch/Apgar, wrap, welcome/skin-to-skin.
• Vigorous newborn: dry, keep warm, assess breathing/tone, skin-to-skin and initiate breastfeeding within 1 h.
• Apgar score is recorded at 1 and 5 minutes, but do not wait for Apgar to start resuscitation.

Initial Assessment

1. Breathing: crying/regular breathing vs gasping/apnea.
2. Heart rate: rapidly determine and reassess during support.
3. Tone/color support assessment, but breathing and HR guide action.

IV. Neonatal Resuscitation Algorithm

Initial Steps

• No breathing or gasping: warm environment, dry, stimulate and position airway neutral/sniffing position.
• Clear mouth/airway only if obstructed; routine suctioning is not recommended.
• Assess respiration and heart rate after initial steps.

Ventilation

• After 30 sec: apnea/gasping or HR <100/min → positive-pressure ventilation (PPV).
• Monitor ECG/SpO2 when available; goal is visible chest movement + rising heart rate.
• If HR remains <100/min after PPV → correct ventilation and consider endotracheal intubation/alternative airway.

Heart-Rate Thresholds

• HR ≥ 100/min + adequate breathing: routine/post-resuscitation care.
• HR < 100/min: ventilation.
• HR < 60/min despite effective ventilation: chest compressions + ventilation.
• Memory: 100 → ventilate; 60 → compress.

Chest Compressions

• Indication: HR remains <60/min despite effective ventilation for 30 sec.
• Ratio: 3 compressions : 1 ventilation.
• Technique: two-thumb encircling technique over lower third of sternum.

Adrenaline and Volume

• Indication: HR remains <60/min despite effective ventilation and coordinated compressions.
• Preferred access: umbilical venous catheter.
• Volume expansion only if suspected blood loss/hypovolemia.