PPHN

Question 1

Pulmonary HTN is usually a dz of which baby?

Answer 1

34 wks-Term (very, very few 23-34 wks)

Question 2

Hypoxia is what?

Answer 2

A relative deficiency of oxygen in Arterial blood

Question 3

What is the OI (Oxygen Index)?

Answer 3

A measure of the severity of Hypoxemia

Question 4

What is the calculatio for OI?

Answer 4

OI= FiO2 x MAP x 100 / post-ductal PaO2

Question 5

It used to be that an OI of 40 or less meant what?

Now what can be considered if pt has PaO2 >50, Optimal MAP, and lung is inflated (good FRC)?

Answer 5

High likelihood of death

ECMO

Question 6

When should you consider ECMO for your pt?

Answer 6

Optimal Lung Function +

Inability to Oxygenate

Question 7

What % chance does he say ECMO will hurt baby?

How?

Answer 7

10%

Stroke, bleed, etc

Question 8

Is there NNP school training for ECMO?

Answer 8

No, it’s OJT baby

Question 9

Is PPHN a dz?

Answer 9

No, it’s a complication (physiology that accompanies other acute dz’s)

Question 10

There are 2 PPHN’s. What are they?

Answer 10

1. That of an acutely ill baby

2. That of the damaged, growing lung (BPD, CLD–>pulm arteries don’t grow, blood vessels damaged)

Question 11

PPHN is caused by primary a primary dz process (3 types). Name them.

Answer 11

1. Lung (MAS, RDS, pneumonia, lung hypoplasia)
2. Pulmonary vascular (idiopathic)
3. Cardiac dysfunction

Question 12

What is the most likely cause of PPHN?

Answer 12

MAS

Question 13

Can Trisomy 21 cause PPHN?

Answer 13

Yes, due to clamping down of pulmonary arteries

Question 14

What b/p does PPHN refer to?

Answer 14

B/P in the lungs.

It does not mean when or what the cause is.

Question 15

PPHN of the newborn has marked what? (3)

Answer 15

Pulmonary HTN
Vasolability
Hypoxemia (from extrapulmonary R->L shunting at FO or DA—skips the lung)

Question 16

What is the incidence of PPHN?

Answer 16

2 : 1000 live births

Question 17

What is the clinical presentation of PPHN

Answer 17

Labile hypoxemia

Question 18

What are the clinical signs of PPHN?

Answer 18

Tachypnea, Retractions
RDS
Progressive Cyanosis
-all signs of underlying lung dz

Question 19

When would you think about PPHN as your dx?

Answer 19

When oxygenation is out of proportion to everything else.

Can ventilate, can’t oxygenate

Question 20

What are some common threads in PPHN?

Answer 20

1. Elevated Pulmonary vascular resistance
   - arteries either constricted or mal-formed
2. Pulmonary vasoconstriction or maldevelopment
3. Altered vascular reactivity

Question 21

When might we see mal-developed pulmonary arteries in a 23 wkr?

Answer 21

BPD, they develop their lungs in front of us.

Poor nutrition does not make good lungs

Question 22

Altered vascular reactivity results in high pulmonary pressure which may lead to?

Answer 22

R->L shunting across FO or DA
Tricuspid regurgitation (most anterior valve)

Question 23

What signs will you see in an baby w/PPHN with altered vascular reactivity?

Answer 23

Blue baby w/Big Murmur

you will think it’s cyanotic heart dz

Question 24

Is a grade 3/6 murmur common in PPHN babies?

Why or why not?

Answer 24

Yes

b/c the R heart has difficulty pumping into the pulmonary circulation, it flows backwards against tricuspid valve = murmur

Question 25

Changes in PVR depend almost entirely on changes in what?

Answer 25

Vessel Radius

-it doesn’t take much change in radius to make b/p in blood vessel sky rocket.

Question 26

What is the path of Fetal blood flow?

Answer 26

Placenta->Umb Vein->DV->RA->most through PFO->LA->LV->Aorta->Brain->RA->RV->(93% to placenta, 7% to lungs)

• kidney, bowel, skin get left overs
• less w/coarctation (that’s why it happens, less flow there in utero)

Question 27

Only __% of combined CO goes to the lungs and when stressed can be __%

Where is blood sent instead?

Answer 27

7%
1%

To the placenta

Question 28

What is the goal of blood flow during transition from R heart to the lungs?

Answer 28

100%

Question 29

What causes hypoxia in PPHN?

What does this do?

Answer 29

Extrapulmonary shunt (R->L across fetal channels: FO/DA)
Causes them to clamp down and send more blood to "placenta"-which is not there- and diverts blood from the lungs
**they remember and repeat what they did in utero when stressed**

Question 30

PPHN is a vicious cycle of?

It is set up by what?

So what’s important?

Answer 30

Blueness

The intrauterine environment, the more stressed->the more PPHN

A good HX!

Question 31

Would you worry about giving PGE to a baby whom you don’t know is in cyanotic heart Dz or PPHN?

Answer 31

No, you’ll save his life

Won’t hurt him unless you can’t ventilate them (PGE can cause Apnea)

Question 32

cAMP is the “ “ making vessels vasodilate

Answer 32

cAMP is the “boss”

Question 33

Flolan is a potent what?

Answer 33

Vasodilator

Question 34

Is Milrinone a first line drug for PPHN?

Why or why not?

Answer 34

No

Need to have good Systemic B/P (it causes SVR to drop)

Question 35

If you are trying to differentiate PPHN, and note a difference in R. Upper extremity sat vs lower extremity sats, besides PPHN, what could this be?

Answer 35

Coarctation

Aortic interruption

Question 36

How can you dx PPHN? (5)

Answer 36

Hyperoxia test
Differnetial SaO2 or PaO2
Ventilation or Hyperventilation
Echocardiogram
Cardiac cath (rare)

Question 37

What is the gold standard to dx PPHN?

Answer 37

Echocardiogram

Question 38

What 3 organs does oxygenation in the NB depend on?

Answer 38

1. Lungs (adequate FRC)
2. Heart (pump blood to lungs)
3. Pulmonary Arteries (allow blood to enter lungs)