1. Respiratory Distress in the Delivery room
NICU Night Curriculum
University of Chicago Comer Children’s Hospital

2. “Code White”

3. “Code White”
You arrive in the DR
What do you want to know

4. Gestational Age: 40 weeks
Why was code called?: Meconium Stained fluid
Serologies: Negative
Vaginal delivery, ROM 20 hours

5. Mom is 30 y/o G1P0, no PMH
ROM 20 hours, green/yellow color noted in amniotic fluid
Late decels were noted
Nuchal cord x 1
Male baby is born limp, cyanotic, not crying

6. What do you do next?

7. Resuscitation
Laryngoscopy first Meconium aspirator Check heart rate Evaluate Respiratory rate Check Pulses Are there Breath sounds? Give PPV if necessary

8. Equipment What size blade and Endotracheal size tube would you use?
How far would you insert the ETT?
Appropriate Blade:
–Preterm: 0
–Term: 1
Endotracheal tube Size
<1kg = 2.5
1  2 kg = 3.0
2  3 kg = 3.5
> 3 kg = 4
Insertion Depth:
6 + (wt in kg) = cm at lip

9. What do you want to know when looking at the baby (Name 4 things)?
Crying/breathing or not
Respiratory effort, retractions, grunting
Heart rate, pulses
Murmur?
Airway obstruction? (pass suction catheter)
Obvious anomalies/dysmorphic features (i.e. micrognathia, macroglossia)

10. What’s your differential?
Pulmonary diseases
Meconium Aspiration Syndrome
Repsiratory distress syndrome
Pneumonia
Pulmonary hemorrhage
Congenital Heart Diseases
Transposition of the great vessels
Hypoplastic left ventricle
Critical pulmonary stenosis
Severe coarctation of the aorta
Total anomalous pulmonary venous return
Sepsis

11. Physical Exam
HR 100, not crying -> intubate, suction 3 mL of green fluid
Baby starts crying, HR 140
Subcostal retractions, RR 65
Tone and color improve, retractions resolve
Apgars??
To NICU or not?

12. You did not bring baby back to the NICU, but you are called to GCN a little while later….
Baby is tachypneic, grunting, and still retracting, SpO2 80%
What do you do next?

13. Interventions Oxygen therapy Consider PPV on way back to NICU
Place on conventional ventilator if needed
Chest Xray
ABG, CBC, BMP, blood culture, antibiotics
How would you describe the CXR on the next slide?.....

15. CXR Findings: Patchy opacities in both lung fields ETT in place
Atelectasis
Poor heart borders
Air trapping

16. Meconium Aspiration Syndrome
MSAF in 10-15% of births, usually term or post-term
Meconium aspirated in utero or with first breath
Thick, particulate meconium causes small airway obstruction; ball-valve effect
Presents with tachypnea, retractions, grunting in first hours of life
Usually improves within 72 hours except for those that require mechanical ventilation
Some are refractory to conventional ventilation; need HFOV, iNO, and even ECMO

17. Persistent Pulmonary Hypertension
Suspected with hypoxia refractory to conventional ventilation
Occurs with MAS due to hypoxia that triggers pulmonary vasculature remodeling
Normal decline in pulmonary vascular resistance does not occur
Estimated by measuring tricuspid regurgitation on Echocardiogram

18. Epidemiology Predisposing factors for PPHN:
birth asphyxia, meconium aspiration pneumonia, RDS, polycythemia
Often idiopathic, can be genetic
Incidence 1/500-1,500 live births
MAS:
MSAF in 10-15% of births, 5% of those develop MAS, 30% require mechanical ventilation, 3-5% mortality

19. Pathophysiology
PPHN is defined as sustained elevation of the pulmonary vascular resistance after birth, causing right to left extrapulmonary shunting of blood (PDA, foramen ovale) resulting in severe hypoxemia.
Result of increased pulmonary artery medial muscle thickness and extension of smooth muscle layers into the non-muscular peripheral arterioles

20. Diagnosis of PPHN Hyperoxia Test:
Distinguishes cyanotic heart disease from pulmonary disease
Check PaO2 before and after administering 100% oxygen
Should rise to ; If rises above 150, usually can exclude heart lesion
PPHN does not respond to 100% oxygen

21. Severity of PPHN
Oxygenation index (OI) can be used to measure severity of PPHN.
Oxygenation Index: (Mean Airway Pressure x FiO2 x 100)/Pao2
More details on how to interpret these numbers later…
Add what a normal OI is and at what OI you would consider ECMO

22. Clinical presentation
Infants with PPHN are usually delivered at near term, term, or post term, and are commonly AGA.
Clinical findings include tachypnea, grunting, retraction, and cyanosis, especially with stimulation. The hypoxemia in PPHN is labile and disproportionate to the extent of the pulmonary parenchymal disease.
Arterial blood gas shows severe hypoxemia with relatively normal pH and PCO2.
In infants with ductal level shunting, there is a gradient of 10mm Hg between right arm and lower extremity oxygen pressure. If the shunting is intrapulmonary or via PFO, there is no difference in oxygenation of the right arm and the umbilical artery blood.

23. CXR
Chest X-ray reflects the underlying parenchymal lung disease. In infants with idiopathic PPHN, the lung fields are clear and appear undervascularized
For MAS, patchy infiltrates, coarse streaking, increased AP diameter and flattening of diaphragm

24. Treatment
The underlying causes of PPHN, such as hyperthermia, hypoglycemia, hypocalcemia, polycythemia, hypoxia, and acidosis, must be aggressively treated.
Goal of therapy in patients with PPHN is to lower the Pulmonary vascular resistance, maintain systemic blood pressure, reverse the right to left shunts, and improve tissue oxygenation.

25. Treatment continued:
Response often unpredictable (nonresponders vs responders)
If severe, require mechanical ventilation and 100% FiO2
Consider Surfactant initially
Inhaled Nitric oxide = pulmonary vasodilation
Inhaled or IV prostacyclin if no response to iNO
PO Sildenafil and Bosentan once off vent if still having PHTN
ECMO necessary in 5-10% of cases

26. Severity
If Oxygenation index (OI) is greater than 25, begin iNO, usually at 20 ppm but can go to 40 ppm if poor response
If OI continues to worsen, consider ECMO
Potential Side Effects of iNO includes methemoglobinemia secondary to excess iNO

27. Prognosis Survival varies with underlying cause of PPHN
Long-term outcome related to HIE and ability to reduce pulmonary vascular resistance
70-80% survival for those treated with ECMO and 60-75% appear normal at yrs of age

28. Review Questions Neonatal resuscitation Typical presentation of MAS
MAS can lead to PPHN
Treatment
Prognosis

29. PREP 2011 #242
“You are called to attend the c/s delivery of a 42 weeks’ gestation infant because of FTP complicated by severe oligohydramnios. Maternal screens are unremarkable. ROM at delivery reveals scant meconium-stained fluid. Under the warmer, the infant is vigorous and has good respiratory effort, a HR of >100, central cyanosis and meconium staining of peeling ‘post dates’ skin. You begin blow-by oxygen which improves his color, but he develops tachypnea and grunting. He is transferred to SCN where he is intubated and an UVC is placed. Pre- and postductal saturations are 97% while receiving 60% oxygen.” Chest radiography is provided which shows patchy opacification and hyperinflation

30. Of the following, the infant’s clinical presentation is MOST consistent with
Group B streptococcal pneumonia
Meconium aspiration syndrome
Persistent pulmonary hypertension
Retained fetal lung liquid syndrome
Transposition of the great vessels

31. Answer: B. MAS
“The history of post dates pregnancy with severe oligohydramnios, the findings of meconium staining at birth and early-onset respiratory distress, and the CXR make MAS most likely. Congenital cyanotic heart disease is less likely due to this infant’s response to oxygen. Although the infant is at high risk for PPHN, the similar pre- and postductal saturations do not demonstrate shunting at the ductal level. The CXR does not demonstrate diffuse infiltrates or fluid in the fissures which would suggest retained fetal lung fluid syndrome (TTN).”

32. PREP 2010 #130
“You are called to the operative delivery of a 42-weeks’ gestation male following a pregnancy complicated by oligohydramnios and poor fetal growth. MSAF was noted upon AROM. Fetal bradycardia resulted in a decision for c/s delivery. Resuscitation of the infant requires intubation, tracheal suctioning, assisted ventilation, chest compressions, and IV epinephrine. Apgar scores are 1, 3, and 5. You transfer the newborn to the NICU, where he appears cyanotic, in respiratory distress, and agitated. Systemic BP is 35/17. On 100% O2, pulse oximetry in the right upper and left lower extremities reveals sats of 94% and 80%, respectively”….. Chest XR provided reveals atelectasis in the RUL, hyperinflation and patchy infiltrates.

33. Of the following, the MOST likely diagnosis is
Congenital diaphragmatic hernia
Congenital pneumonia
Cyanotic congenital heart disease
Persistent pulmonary hypertension
Respiratory distress syndrome

34. Answer: D. PPHN
“The growth restriction, 42-week GA, oligohydramnios, and depressed condition requiring vigorous resuscitation at birth strongly indicate fetal compromise due to chronic hypoxemia. Although meconium expression does not always equate with fetal stress and may be a normal finding…, the risk for meconium aspiration must be acknowledged when fetal stress is accompanied by abnormal HR and perinatal depression… The difference in pre- and postductal sats indicates that the newborn has a right-to-left shunt and PPHN….”

35. PREP 2009 #194
“You admit a 39 weeks’ GA male who has respiratory distress to the intensive care nursery. His mother had a negative GBS screening culture and did not require antibiotics in labor. She did not have chorioamnionitis or PROM. However, amniotic fluid was meconium-stained at the time of delivery, and the infant required tracheal intubation, with resultant meconium suctioned from below the vocal cords. Apgars scores were 3 and 7. On PE, he has marked work of breathing with tachypnea and retractions and episodic cyanosis when agitated. Breath sounds are coarse and equal. There is no heart murmur. While receiving hood oxygen at an FiO2 of 0.50, his oxygen saturation is 85%. You obtain a CXR.” The radiographic findings most expected for this infant are….”

36. Air bronchograms, diffusely hazy lung fields, and low lung volume
Cardiomegaly, hazy lung fields, and pulmonary vascular engorgement
Fluid density in the horizontal fissure, hazy lung fields with central vascular prominence, and normal lung volume
Gas-filled loops of bowel in the left hemithorax and opacification of the right lung field
Patchy areas of diffuse atelectasis, focal areas of air-trapping, and increased lung volumes

37. Answer: E
“The infant described has respiratory distress and hypoxemia. Air bronchograms in diffusely hazy low volume lungs are most consistent with surfactant deficiency-related respiratory distress syndrome. Cardiomegaly with hazy lung fields and pulmonary vascular engorgement is seen in left-sided obstructive cardiac disease states or with pulmonary overcirculation (eg, truncus arteriosus, aortic stenosis, transposition, anomalous pulmonary venous return) When gas filled loops of bowel are seen in the chest, diaphragmatic hernia is the diagnosis.”

38. “Specialty Board Review: Pediatrics”
Which medication used by the mother during pregnancy is the most likely to cause PPHN in the newborn
phenobarbital
captopril
aspirin
bupropion
levothyroxine

39. Answer : aspirin
“constriction of the fetal ductus arteriosis may lead to PPHN. Of the medications listed, only aspirin does this. Other NSAIDS can also do this.”

40. Learning Objectives
Review assessment/resuscitation of neonate in delivery room
Review pathogenesis of meconium aspiration syndrome and PPHN
Review treatment and prognosis for MAS and PPHN

41. References Nelson Textbook of Pediatrics Nadas’ Pediatric Cardiology
PREP 2009, 2010, 2011
Specialty Board Review: Pediatrics