Neonatal Respiratory Disorders

Table Of Contents
  1. General Approach to Neonatal Respiratory Disorders
  2. Neonatal Respiratory Distress Syndrome (NRDS)
  3. Transient Tachypnea of the Newborn (TTN)
  4. Meconium Aspiration Syndrome (MAS)
  5. Congenital Pneumonia
  6. Choanal Atresia
  7. Spontaneous Pneumothorax
  8. Congenital diaphragmatic Hernia (CDH)

General Approach to Neonatal Respiratory Disorders

  • Cardinal signs of respiratory distress
    • Tachypnea (>60rpm)
    • Cyanosis on room air
    • Expiratory grunting (on auscultation)
    • Intercostal/sternal retractions (easy to see since babies are small and thin)
  • Investigations to order
    • CXR ( + Hx – meconium, complications in OB etc. will give dx in most cases)
    • ABGs
    • Pulse Ox
    • Routine labs (CBC, U/E/Cs, RBS etc)
    • Blood culture
  • Treatment
    • Supplemental oxygen: warmed and humidified, maintain pulse ox at 92-96%, PaO2 at 60-70mmHg
    • Monitor for apnoea: will need to mechanically intubate (intubation carries risk of lung damage)
    • D5W or D10W; monitor U/O, Glucose, Electrolytes, ABGs
    • Broad spectrum ABX (if congenital pneumonia can’t be r/o)
  • Absolute indicaitons for intubation
    • Apnoea
    • PaO2 <60 mmHg on > 60% FiO2
    • PaO2 > 60mmHg
  • What should you consider if the baby continues to be cyanotic on oxygen supplementation (Hyperoxic test)
    • Cause of cyanosis is likely to be Cardiac in origin (cyanotic congenital heart defects → TGA, TOF)
    • TGA – presents in the neonatal period
    • TOF – most common cyanotic heart defect

Neonatal Respiratory Distress Syndrome (NRDS)

MCC of respiratory distress in the preterm neonate (keep this in mind when you have a preterm neonate with respiratory distress). Diagnosis is by clinical presentation and CXR. Use of antenatal steroids reduces RDS by an average of 40%.

Affects 5% (1 in 20) of babies born btw 35-36 weeks of gestation and 50% of babies born btw 26-28 weeks. M>F.

  • Predisposing factors
    • Diabetic mother
    • Caeserean section OR precipitous delivery
    • Asphyxia
    • Cold stress
    • Second twin
    • Hx of RDS in a sibling
  • Cause
    • Surfactant deficiency → atelectasis
    • Surfactant production begins at week 20-24 of gestation, and matures after week 35 of gestation.
  • Signs and symptoms
    • Respiratory distress (tachypnea, intercostal indrawing, grunting, cyanosis, flaring of nasal alae)
    • Decreased air movement (on auscultation)
    • Reduced lung sounds
    • Nasal flaring
  • Investigations
    • CXR:
      • Diffuse bilateral atelectasis (diffuse ground glass appearance),
      • Air bronchograms (contrast of aerated airways vs collapsed airways),
      • Hypoinflation
    • ABGs: hypoxemia, hypercapnia, respiratory and metabolic acidosis
    • U/E/Cs: hyponatremia (d/t fluid retension)
    • CBC + CRP: evaluate the possibility of early-onset NNS in a preterm baby (clinically indistinguishable from RDS)
  • Treatment
    • Supplemental O2 via nasal CPAP
    • Intubation for surfactant administration: definitive treatment
    • Antenatal prophylaxis: administer betamethasone to mother in preterm labor (at least 24 hrs before deliver). Accelerates surfactant production.
    • Prophylactic surfactant for all neonates born ≤ 27 wog
Hyaline Membrane Disease
Hyaline Membrane Disease

Transient Tachypnea of the Newborn (TTN)

Mild, temporary respiratory distress d/t retained fluid in the foetal lungs – which is a function of how the baby was delivered. It is a self-limited condition resolves within 72 hours. MCC of neonatal respiratory distress.

  • Cause
    • Retained fetal lung fluid (should have been absorbed into circulation during labor)
      • Short second stage of labor (delivery stage)
      • C/S (in which ROM has not occurred)
  • Risk factors
    • Large premature infant
    • Term infant born by precipitous delivery
    • Diabetic mother
  • Rule of 1/3
    • 1/3 reabsorbed during late gestation
    • 1/3 mechanically expelled during birth
    • 1/3 during crying
  • Investigations
    • CXR
      • Retained fluid (perihilar streaking; opacity along interlobar fissures),
      • Hyperexpansion
      • Small pleural effusion (occassionally)
  • Treatment
    • Nasal CPAP (in the presence of cyanosis/hypoxia)
    • Empiric antibiotics (Penicillin and Gentamicin) or at least 48 hours until neonatal sepsis has been ruled out.
    • Monitor for signs of clinical deterioration.
    • Resolves spontaneously within 12-24 hours
Transient Tachypnea of the Newborn
Transient Tachypnea of the Newborn

Meconium Aspiration Syndrome (MAS)

Diagnosis is by CXR and clinical presentation (meconium in show is big red flag; alert neonatologist on call)

  • Cause
    • Aspiration of amniotic fluid containing meconium
      • Significant fetal distress
      • Post-term babies
  • Signs and symptoms
    • Coarse breath sounds, wheeze on auscultation
    • Barrel chest appearance (d/t air trapping and hyperinflation)
    • Meconium in show
    • Meconium stained nails, skin, and umbilical cord
  • Investigations
    • CXR: irregular infiltrates, hyperexpansion, lobar consolidation in severe cases
    • ABGs
    • CBC: r/o infection as cause of in-utero stress
  • Treatment
    • Neonatal resuscitation based on status on deliver
    • Suction nose and mouth
    • Suction trachea if:
      • Bradycardic
      • Poor respiratory effort
      • Poor muscle tone
    • Positive pressure ventilation and careful SpO2 monitoring
    • Admit to NICU
    • Insert umbilical artery catheter (to monitor ABGs)
    • Monitor Hgb (oxygenate to > 13g/dL)
    • Consult neonatologist on-call
  • Complication
    • Chemical pneumonitis
Meconium Aspiration Syndrome
Meconium Aspiration Syndrome

Congenital Pneumonia

Lungs are the MC site of infection in the neonate. Commonly acquired from the vaginal tract and presents in the first 2 months of life

  • Risk factors
    • GBS+ mother
    • ROM > 18 hrs
    • Maternal fever
    • Chorioamnionitis
    • Premature labor
  • Most common organisms
    • GBS
    • E. coli
  • Signs and symptoms
    • Respiratory distress
    • Adventitious lung sounds
    • Temperature instability (neonates are not like adults and will not always present with fever if infected)
    • Sx of sepsis
  • Investigations
    • CXR: diffuse infiltrates, atelectasis, hyperexpansion, blunted costophrenic angles (Like HMD but with later presentation)
    • Blood cluture
    • Pancultures(blood, CSF, Urine): in neonates who are febrile and appear septic even inf Dx is apparent
  • Treatment
    • Broad spectrum ABX
    • Supplemental Oxgen
    • Admit
    • IV acyclovir (if baby does not show signs of improvement
Congenital Pneumonia
Congenital Pneumonia

Choanal Atresia

Emergency. Maldevelopment of the nasopharyngeal tract resulting in obstruction. Occurs in 1/7,000 births F>M. Results in life-threatening respiratory distress when bilateral (babies are obligate nose breathers

  • Associated with
    • Thyroid suppressing medications during pregnancy
    • Smoking during pregnancy
  • Signs and symptoms
    • Baby was normal at birth when crying
    • Bradycardic and cyanotic baby (when crying stops or during feeding)
    • Inability to pass a 6-Fr catheter through the nose
  • Investigation
    • Axial CT: confirmatory
  • Treatment
    • Intubate: immediately
    • Consult peds ENT: for surgical correction
    • ECG: 50% with bilateral atresia will have CHARGE association
Choanal Atresia
Choanal Atresia

Spontaneous Pneumothorax

Occurs in 1% of all deliveries and is associated with PPV and renal anomalies

  • Signs and symptoms
    • Respiratory distress
    • Reduced or absent breath sounds on the affected side
    • Shift of heart sounds towards the affected side
  • Investigations
    • CXR: pneumothorax on affected side (blackening), mediasinal side
  • Treatment
    • If baby was on room air when pneumothorax happened and hasn’t been intubated
      • 100% O2 for a few hours
      • Monitor SpO2
    • Otherwise, or if significant respiraotry distress, or if does not improve on 100% O2
      • Thoracocentesis
      • Tube thoracostomy
Spontaneous Pneumothorax
Spontaneous Pneumothorax

Congenital diaphragmatic Hernia (CDH)

A CDH is failure of the diaphragmatic tissue to fuse resulting in a defect that allows abdominal contents to herniate into the thoracic cavity. Main issue with this is respiratory insufficiency **(**hypoplasia on the affected side). Commonly occurs on the left. Dx prenatally via sonography.

  • Signs and symptoms
    • Respiratory distress (use of acc. muscles, nasal flaring, cyanosis)
    • Scaphoid abdomen
    • Shift of heart sounds to the right
    • Tachypnea
    • Bowel sounds or absent breath sounds on the affected side
  • Investigations
    • CXR
      • Abdominal contents in the thoracic cavity
      • Shifted mediastinum
  • Treatment
    • Admit to NICU
    • Intubation and gentle mechanical ventilation (allow a bit of hypercapnia); can put on ECMO
    • NG decompression
    • IV fluids and glucose
    • Delay surgery for 24-48 hours to allow for improvement in pulmonary hypertension
Congenital Diaphragmatic Hernia
Congenital Diaphragmatic Hernia