Persistent Pulmonary Hypertension in the Newborn

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Persistent Pulmonary Hypertension in the Newborn
A Star Fleet Academy Short Course
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Pulmonary Hypertension

• Examples
• NSAIDS during pregnancy
• Persistent fetal circulation
• Total anomalous pulmonary veins
• Mitral valve stenosis / diabetic cardiomyopathy
• Pulmonary hypoplasia / diaphragmatic hernia

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Fetal closure of the ductus arteriosus
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Pulmonary artery constriction
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(tricuspid regurge)
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(commonly seen on echo)
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There are two mechanisms of right to left
shunting in the fetus
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(No Transcript)
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?
How do we know the cause of a newborns cyanosis?
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Damn it, Im a doctor! Not a mind reader!
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You dont have to use the mind meld, Bones,
(All it takes is two sat probes)
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95
Does this child have PPHN?
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90
Does this child have PPHN?
95
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How can we reverse persistent fetal circulation?
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Damn it, Im a doctor! Not a miracle worker!
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You dont need to be a miracle worker, Bones,
All you need is a rudimentary understanding of
plumbing
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• Things that reduce Pulmonary Vascular Resistance
• Optimal Lung Expansion
• High PaO2
• Nitric Oxide
• Prevention of acidosis / normal to mildly
  alkalotic pH
• Sedation and when necessary paralysis
• Treatment of infection

• Things that increase Systemic Blood Pressure
• Pressors Dopamine is your first choice
• Fluid boluses (crystalloid)
• Colloid as appropriate
• Prevention of acidosis / normal to mildly
  alkalotic pH
• Treatment of Infection

• Things that can complicate matters
• Stimulation giving a bath, loud noise,
  unnecessary handling
• Spontaneous respirations not in sync, valsalva
  effects

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POP QUIZ!
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3 hour old male 40 week male , now on CMV 26/4 x
30 on 100, 35/20 bp, being transported for
presumed cyanotic heart disease. You arrive at
the outside hospital, see the postductal SaO2,
add a preductal SaO2. What are some immediate
therapy options that you want to suggest to the
transport physician when you call?
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89
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Now what are you going to do?
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93
89
Anything else?
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Is this child stable to transport?
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When is a child too unstable to transport?
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Damn it, Im a doctor! Not a cargo handler!
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Sometimes we must endeavor to be both, Bones,
Judgment is required to discern which vocation
should predominate in any given clinical case
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Knowing when to stabilize ad nauseum and when to
grab and go is part of the art of transport
medicine. Particularly when it comes to a disease
like PPHN. There are some children who simply are
not going to get substantially better because
they have fixed or severe acute limitations to
their physiology (pulmonary hypoplasia, sepsis,
or an in utero closure of the ductus). In these
cases, the basic modes of stabilization should be
implemented and then the child may need to be
quickly transported before they deteriorate
further. In other cases, if a trend of clear
improvement is evident with interventions, it may
be more prudent to optimize stabilization before
transport. The art of transport medicine is
stretched thin in making the right decision with
each patient who has PPHN. There are a few pearls
that can facilitate decision making, in
particular the grab and go.
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Fetal hemoglobin holds onto oxygen better than
adult hemoglobin (like Vulcan blood) and so
infants with PPHN will still have some O2
delivery to their tissues at lower PaO2s. Because
infants with PPHN have not transitioned, they are
still used to fetal oxygenation levels.
Maternal Blood
Fetal Blood
Vulcan De-oxygenated Blood
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If you are transporting one of the more unstable
PPHN patients you may have difficulty maintaining
adequate oxygenation with conventional
ventilation. Unless your ventilator is a JET (or
has a positronic brain), a transport clinician is
sometimes faced with a Kobayashi Maru type
scenario (a seemingly unsolvable dilemma). The
problem is how to maintain oxygenation in a child
who has little or no pulmonary perfusion.
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1) The first and most important thing is to NEVER
give up! 2) The second most important thing is to
use all the information at your disposal and to
continue stabilization throughout the
transport. 3) The third thing is to do what
works. In some cases, high frequency, hand
bagging with intentional breath stacking will
result in sufficient optimization of lung volumes
and transient respiratory alkalosis buying you
oxygenation and time to get through the
transport. Each PPHN case is different and will
have a different sweet spot.
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What is a Sweet Spot?
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The Sweet Spot is the constellation of variables
(blood pressure, ventilation settings, oxygen
requirement, need for nitric oxide, need for
alkalinization, etc.) at which a child with PPHN
begins to show clear evidence of improved
oxygenation. In simple terms, it is when the
plumbing is working correctly. Once you find the
sweet spot, you want to figure out which
variables most strongly contribute to that
stability and try to keep them optimized during
the transport.
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Resistance is Futile! time for another POP
QUIZ
You are transporting a 38 week old, 3.5 kg male
with a left-sided diaphragmatic hernia. Pre and
postductal sats have been 95 and 80 respectively.
BP 55/35, CMV 29/5 x 40 _at_ 100 on NO and 8
mg/kg/min of dopamine. You are half way through
the transport when the alarms start to go off.
The sats plummet to 65 and 60, the BP is 35 over
20, there is chest rise although it appears
asymmetric. rise is better on the right.
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Now youve done it! Youre sats are 40 and
undetectable. Your pressures are 22 and 10. The
kids color is aquamarine. I dont know what
youre doing wrong, but whatever it is, you need
to do stop and do something right. What else
could be causing this sort of catastrophic change
and what can you do to keep this child alive
until you can get to ECMO?
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Remember that you can call for help. These are
the worst possible cases to trouble shoot. In
nearly every case, a nurse practitioner will be
there with you. Even so, sometimes it is the
junior person who thinks of the right answer, or
who asks the right question or says, do you
think we should call and ask for advice? The key
to trouble shooting complex patients is to keep
your mind engaged and to keep sifting through the
data in front of you. Dont let your brain get
frozen.
PLEASE STATE THE NATURE OF THE MEDICAL EMERGENCY
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WHAT TO TELL THE PARENTS i.e. how scared should
they be when youre done talking?

1. Most patients with idiopathic PPHN do not have to
   go on ECMO (because of NO).
2. Those who do go on ECMO without severe hypoxic
   insult have good neurodevelopmental outcomes.
3. Diaphragmatic hernias are different, it depends
   on the size of their lungs / lesion.
4. About 1/3 of diaphragmatic hernias die, despite
   aggressive therapy, but the outcomes of survivors
   are good (from a neurodevelopmental point of
   view).
5. All patients with PPHN have increased risk of
   late onset high frequency hearing loss.
6. The primary risk for neuromorbidity and death is
   prolonged hypoxia prior to stabilization in an
   ECMO center (doesnt that make you feel better?).

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Course Outline I. Causes of Pulmonary
Hypertension a. persistent fetal
circulation b. cardiac strain or failure,
cardiomyopathy c. closure of the ductus in
fetal life d. pulmonary hypoplasia II.
Immediate management of persistent pulmonary
hypertension in the newborn period a. a word
about pre and post ductal saturations
b. optimal ventilation / oxygenation
c. optimal systemic blood pressure d.
sedation / paralyzation III. Management in the
transport environment a. nitric oxide
b. non-acidosis versus alkalinization c.
electronic monitoring IV. Overall Goals for a
transport team short term versus long term
goals - survival, long term
hearing, stability to ECMO
You humans are pathetic, if you just had
spiracles and trabechulae, instead of lungs, your
larvae would never get PPHN.