Inhaled Nitric Oxide use in Newborns Flashcards

1
Q

Where is NO generated naturally in humans

A

lung endothelium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What does NO do to the bodys physiology

A

it diffuses into vascular smooth muscle cells

→ activates guanylate cyclase which leads to increased cyclic guanosine monophosphate

→ pulmonary vasodilatation and improve VQ matching

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How do you calculate the oxygenation index

A

OI = (FiO2 x MAP x 100)/PaO2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Who should be treated with iNO

A

35 wks GA and over
Hypoxic respiratory failure not responding to conventional management
OI over 20
PaO2 less than 100mmHg despite 100% FiO2

NOTE: not effective for most kids with CDH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What should you do pre iNO

A

Echo: RO cyanotic CHD and assess pulmonary BP

OI calculation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Are there indications for iNO in premature infants

A

Respiratory failure secondary to oligohydraminos

NOT: BPD or rescue for very sick

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the risks of iNO in premature infants

A

IVH
PVL
+ uncertainty regarding neurodevelopment outcomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the half life of iNO

A

2-6s

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What does do you start at and what is the maximum dose

A

in term:
20 ppm and increase to 40 ppm
above 40 ppm can get toxicity

in preterm:
10 ppm and increase to 20 ppm
They have less methemodlobin reductase so can only tolerate lower doses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is considered a positive response to iNO

A

response should be rapid (within 30 minutes)

increased PaO2 by at least 20 mmHg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

When would you wean iNO

A

after 4-6 hours of stability

O2 decreased to 60-80% or OI falls to less than 10

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How do you wean and why do you do it this way

A

you wean gradually: decrease by 50% Q4-6H, once you get to 5 ppm, you wean by 1 ppm Q4H
Discontinue: infant is well on 1 ppm, with PaO2 over 50 and FiO2 less than 60%
You wean slowly because you get down-regulation of endogenous NO production on iNO and abrupt cessation can cause severe hypoxia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the typical duration of iNO

A

96 hours

if the kid still needs iNO at 7 days you should look for other forms of lung and cardiac pathology

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Is iNO toxic

A
it can be
Main concerns: 
1. production of NO2 - causes pulmonary injury when over 5 ppm
2. methemoglobin
3. decreased platelet aggregation
4. increased risk of bleeding
5. Sufractant dysfunction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is methemoglobin and why does it matter

A

when NO is absorbed into the blood, it binds with the ion of the heme protein producing nitrosyl-hemoglobin. This is oxygised to methemoglobin.
Need to keep less than 2.5%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly