Respiratory Distress in
the Delivery room
NICU Night Curriculum
University of Chicago Comer Children’s Hospital
“Code White”
• 2222 234
“Code White”
• You arrive in the DR
• What do you want to know
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Gestational Age: 40 weeks
Why was code called?: Meconium Stained fluid
Serologies: Negative
Vaginal delivery, ROM 20 hours
• 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
What do you do next?
Resuscitation
Laryngoscopy first
Meconium aspirator
Check heart rate
Evaluate Respiratory rate
Check Pulses
Are there Breath sounds?
Give PPV if necessary
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
What do you want to know when
looking at the baby (Name 4 things)?
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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)
What’s your differential?
• Pulmonary diseases
o Meconium Aspiration Syndrome
o Repsiratory distress syndrome
o Pneumonia
o Pulmonary hemorrhage
• Congenital Heart Diseases
o Transposition of the great vessels
o Hypoplastic left ventricle
o Critical pulmonary stenosis
o Severe coarctation of the aorta
o Total anomalous pulmonary venous return
• Sepsis
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?
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?
Interventions
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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?.....
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CXR Findings:
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Patchy opacities in both lung fields
ETT in place
Atelectasis
Poor heart borders
Air trapping
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
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
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
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
Diagnosis of PPHN
• Hyperoxia Test:
o Distinguishes cyanotic heart disease from
pulmonary disease
o Check PaO2 before and after administering 100%
oxygen
o Should rise to 400-500; If rises above 150, usually
can exclude heart lesion
o PPHN does not respond to 100% oxygen
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…
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.
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
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.
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
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
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 1-3.5 yrs of
age
Review Questions
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Neonatal resuscitation
Typical presentation of MAS
MAS can lead to PPHN
Treatment
Prognosis
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
Of the following, the infant’s clinical presentation is MOST
consistent with
A.
B.
C.
D.
E.
Group B streptococcal pneumonia
Meconium aspiration syndrome
Persistent pulmonary hypertension
Retained fetal lung liquid syndrome
Transposition of the great vessels
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).”
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.
Of the following, the MOST likely diagnosis is
A.
B.
C.
D.
E.
Congenital diaphragmatic hernia
Congenital pneumonia
Cyanotic congenital heart disease
Persistent pulmonary hypertension
Respiratory distress syndrome
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….”
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….”
A.
B.
C.
D.
E.
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 airtrapping, and increased lung volumes
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.”
“Specialty Board Review:
Pediatrics”
Which medication used by the mother during
pregnancy is the most likely to cause PPHN in the
newborn
A. phenobarbital
B. captopril
C. aspirin
D. bupropion
E. levothyroxine
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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.”
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
References
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Nelson Textbook of Pediatrics
Nadas’ Pediatric Cardiology
PREP 2009, 2010, 2011
Specialty Board Review: Pediatrics
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