Transcript The “regular preemie” and the VSBW preemie

The “regular preemie”
and
the VSBW preemie
By Elizabeth Kelley Buzbee
AAS, RRT-NPS, RCP
Infant mortality
• Infant mortality is defined
as the number of babies who
die in the first year of
life/1000 live births.
• According to the CIA fact
book , the USA had an IM
rate of 6.37 in 2007.
There are 41 countries with
better stats than we have.
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http://en.wikipedia.org/wiki/List_of_countries_by_infant_mortality_rate_(2005)
Problems with comparisons
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A 2006 article in U.S. News & World Report
states, "First, it's shaky ground to compare
U.S. infant mortality with reports from other
countries. The United States counts all births
as live if they show any sign of life, regardless
of prematurity or size. This includes what many
other countries report as stillbirths.
In Austria and Germany, fetal weight must be
at least 500 grams (1 pound) to count as a live
birth…...
In Belgium and France, births at less than 26
weeks …. And some countries don't reliably
register babies who die within the first 24
hours of birth.
Thus, the United States is sure to report
higher infant mortality rates. For this very
reason, the Organization for Economic
Cooperation and Development, which collects
the European numbers, warns of head-to-head
comparisons by country."
http://en.wikipedia.org/wiki/Infant_mortality_rate
Newborn morbidity & mortality
• The single most common cause of mortality
and morbidity in the newborns in the USA
is prematurity.
• Among the 4,058,814 births in the USA in
2000, (11.6%) were born preterm as
defined as less than 37 weeks gestational
and (1.43%) were VLBW [AGRQ]
• According to the March of Dimes, about 12
percent of babies … are … preterm and of
these, 84% are born between 32-36 weeks
[risk of HMD] with 10% between 28-31 and
only 6% of these less than 28 weeks
premature.
http://www.musckids.com/health_library/hrpregnant/ptl.htm
risk factors for prematurity include:
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Teenage unwed pregnancy. [15 YO & younger
also at high risk of preeclampsia which can lead
to eclamsia [Seizures in the mom] the
treatment for eclampsia is delivery of the
baby.[Merck manual]
Maternal history of early labor, multiple
miscarriages or abortions [ 1 preterm labor
increases risk 15%; 2 increases risk 32%. [Czervinske
pp.20]
Multiple births [twins, triplets] vrs singletons
[role played by fertility drugs may be
significant] According to the U of Washington,
Up to 40 % of twins, most triplets and all
quadruplets are born prematurely ……In the past
20 years, the number of multiple births has
nearly doubled
http://uwnews.washington.edu/ni/article.asp?articleID=2995
Poor prenatal care [see teenaged moms]
The VSBW infant less than 1500
grams:
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Prematurity is defined as a child
born before 37 weeks
the VLWB infant is the one
whose birth weight is less than
1500 gram [.68 pounds]
This category of infants accounts
for the highest neonatal
mortality and morbidity among
newborns, as well as significant
tangible and intangible lifelong
costs to the family and society
for medical care, and ancillary
health and educational services.
[AGRQ]
• 96% of infants with birth
weights between 1251 and
1500 grams survive
• in contrast to 77% of
infants with birth weight
less than 1250 grams
[Stevenson,
Wright, Lemons, et al., 1998] [AGRQ]
2nd trimester: Gestation and
development
• week # 16 bronchioles are
forming
• type I and Type II cells are
starting to differentiate
• week 24: Surfactant is starting
to be created at week 24
• airways terminate into lung buds,
and there are no true alveolar sac
and ducts at this time
2nd trimester: Gestation and
development
• week 20: capillaries start at the
alveolar level, but are still
incomplete by 24 weeks.
• Week 26 is the time that true
diffusion of gases can occur
• 24th week Diaphragm is fully
functional and the baby
establishes his FRC with
breathing fluid
2nd trimester: Gestation and
development
• By 20 weeks, the spinal cord get
myelin & baby starts a sleep
cycle.
• If he becomes hypoxemic at this
point he can respond with
increased VE—but
chemoreceptors are not
dependable
• week 16 lower intestines collect
meconium
• 18th week fetus sucks and
swallows amniotic fluid
3rd trimester: Gestation and
development
• At week 30 the fetus will “practice
breathing” is at a RR of 30 bpm
• Surfactant at near normal rates by
week 36, so IRDS is rare unless the
mom has diabetes
• True alveoli are present
• By 28 weeks some regulation of body
functions [nervious system] and by 32
week more reflexes present
• the peripheral chemoreceptors react
to lower Pa02 during this time-- but
are still unreliable
3rd trimester: Gestation and
development
• With alveoli and pulmonary
capillaries formed, gas
diffusion is complete—will
not be as good as adults for
quite some time.
• P(A-a)D02 is twice the
adults.
conclusions
• a 24-week premature infant is only
considered ‘potentially viable,’ many
will not make it
• premature infants over 26 weeks
have fair mortality with frequent
serious lifelong problems
• most 28-week premature infants
have excellent prognosis
• premature infants of 36-38 weeks
are basically “feeders and
growers”.. we feed them and they
grow.
• VLBW infants have increased
risk of almost all the hazards and
complications of premature birth
differences in these children:
cardio-pulmonary:
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the normal newborn has relatively ineffective
lungs [10x RAW and 1/10th the C]; his VT and IC
are so close that his only response to hypercapnia
is to increase RR. He cannot afford any
limitations to breathing.
the worse the lung disease, the more likely the
baby will suffered from pulmonary HTN that can
lead to right heart failure
the most common cause of PDA is hypoxemia that
causes the ductus to re-open
when the PDA is accompanied by pulmonary HTN
the result is persistant fetal circulation-that
problem can be fixed only by hyper-oxygenation
and respiratory alkalosis
these increases in mechanical ventilation will
increase chances for barotrauma, 02 toxicity and
can lead to BPD
differences in these children:
nervous system
increased chance of
intraventricular hemorrhage
[IVH]
delicate blood vessels in the
head
this is such a problem that
we don’t allow tiny preemies
head to go flat much less
head down.
Incomplete chemoreceptors
that fail to respond can lead to
apnea and bradycardia that can
quickly result in death; we keep
differences in these children:
metabolism
to get warm, the preemie uses nonshivering thermogenesis in which
thyroxine and nor-epinephrine
trigger metabolism of brown fat
which involves accelerated 02
consumption & glucose consumption.
the smaller preemies have no fat
stores for insulation and no
muscle mass for shivering-both
ways we adults conserve heat.
the preemie has increased surface
area for heat loss; huge heads
The VLBW infant may not have the
brown fat for heat production
The result is that there is
increased metabolism of 02 to
get warm. Cold stress
Is a trigger for hypoxemia & for
differences in these children:
immunities
Sepsis in the VLBW:
most congenital/ perinatal infections result
in sepsis because of the unhealed
umbilical cord is a conduit for bacterial
infections to tract up into the blood
steam
The National Epidemiology of Mycosis Study
Group reported that over a 2-year
period…… 1.2% of all neonates developed
candidemia, and of these, 82% were
VLBW. [Neely pp. 404]
Because of the problems with heat
generation, even the larger preemie may
not be able to create enough heat for a
fever as a symptom.
A TCH study [10 year review] showed that in
the general population of the NICU, .4%
were diagnosed with candidal meningitis,
but there were 1.1% of the infants under
1500 grams [almost 3 fold
increase]
differences in these children:
GI tract/ nutrition
Necrotizing enterocolitis [NEC]
decreased blood flow to GI tract
results in damage to the tissue and
bowel perforation.
Incidence is about 10% of VLBW infants
[Pietz]
mortality is about 30% in general population
but 66% in VLBW infants [Yeo]
chronic hepatic injury secondary to
prolonged TPN
short gut syndrome: complication of
severe or multiple NEC
osteomalacia due to poor nutritional
support
90% of VLBW infants are in the 10
percentile for growth at 26
weeks and by 18 to 22 months of
age 30-40% are still significantly
below weight
differences in these children:
susceptibility to eye damage
Retinopathy of
prematurity ROP: 0ne
Indian study found 46%
of infants under 1500
grams with varying
degrees of ROP.
http://www.ncbi.nlm.nih.gov/pubmed/9141799
Blindness due to ROP is
directly related to the
degree of prematurity
and even in the face of
improved care, only 20%
of treated children will
have perfect vision.
differences in these children:
pulmonary complications
Increased chance of subglottic stenosis
during prolonged intubation & poor
outcomes with tracheostomy [committed
for entire year]
Time constants and pneumothorax: need to
watch inspiratory times
02 and barotrauma lead to Bronchopulmonary
dysplasia
BPD: A severe chronic lung disease that
results in both obstructive and
restrictive defects. 50% in infant under
1000 grams [total BPD in neonatal
population is 5-30%]
While more infants survive BPD than die,
those with severe BPD who die will
succumb to cor pulmonale, pulmonary
infections or during exacerbations of
the chronic lung disease
differences: neurological
increased chances of IVH,
infections, white
matter damage and
anoxic encephopathy
resulting in increased
incidences of Cerebral
Palsy, blindness,
deafness, seizure
disorders, and mental
retardation.
It is not uncommon to find
a child with CP, seizure
disorders and profound
mental retardation
cost to society
The definition of disability in children …..
based on a definition passed by Congress in
1996. Under Title XVI, a child under age 18
years will be considered disabled if he or she
has a medically determinable physical or
mental impairment or combination of
impairments that causes marked and severe
functional limitations, and that can be
expected to cause death or that has lasted or
can be expected to last for a continuous
period of not less than 12 months. [AHRQ]
According to the US census of 2000, 11% of
the children in the USA have physical or
mental disabilities.
cost to society
According to the National Educational
Association, the cost of special
education is about $16,921 per child
and there are 6 million youngsters
with a wide array of disabling
conditions.
[http://www.nea.org/specialed/index.html
American Institution for Research
[funded by Department of Education]
estimates the cost of special ed at
$50 billion for 1999-2000
http://www.nea.org/specialed/index.html
cost to society
The emotional cost
The perception of most parents of handicapped
children and of the population in general is that
their divorce rate is high and the remarriage rate is
low, but statistics may not support this.
cost to society
According to some studies, the divorce rate among
parents of handicapped children is at 50% right
along with the general population, but that the rate
of divorce of very young parents of handicapped
eldest child is much higher. Advocacy West Lancs
“In a 1994 study of 8th graders, “families of
children with disabilities showed higher
percentages of divorce or separation, lower family
incomes, and more single-parent households than
did the families of the remaining children.” [Hodapp]
Another study of divorce rates …. with Down’s
syndrome showed similar numbers to the general
population, but did show that of the broken
marriages, most of the divorces occurred in the
first 1-2 years of the child’s life. [Rosel]
cost to society
The emotional cost
One UK study of parents of disabled [2-18 year
olds] showed that parents may have ‘lost’ aspects
of personal identity, feel frustrated with dealing
with social and medical services, and got
distressed when their child was in physical pain.
They wanted their normal children to have positive
interactions with the handicapped child. Parents
did not want to learn enough of their child care to
‘take over’ from the professionals because they felt
a great need for the professional support.
http://www.york.ac.uk/inst/spru/pubs/rworks/aug2007-03.pdf
Mothers felt isolated in the home, while the father
suffered feeling of exclusion from the child’s care
even resentment as the mother tended to get most
of the medical information and the professional
support while dad was at work.
http://www.cafamily.org.uk/fathers.html
New 2005 Guidelines
for ALS in the L & D
Infants for whom CPR in the L&D is not
indicated:
Birth weight under 400 gram [
gestation less than 23 weeks]
Congenital anomalies
incompatible with life or with
exceptionally high early
mortality such as trisomy 13 &
anencephaly
In conditions with anticipated
parental burden to the child is
high, the parents’ wishes to be
supported. [AHI pp. IV-193]
References:
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Neely & Schreiber; Fluconazole Prophylaxis in the Very
Low Birth Weight Infant: Not Ready for Prime Time
PEDIATRICS Vol. 107 No. 2 February 2001, pp. 404-405
Fernandez, M, Moylett, EH, Noyola DE and Baker, CJ:
Candidal Meningitis in Neonates: A 10Year Review. Clinical
Infectious Disease August 2000
http://www.journals.uchicago.edu/doi/full/10.1086/313
973?cookieSet=1
AGRQ: US Agency for Healthcare Research and Quality
disability and VLBW
http://www.ncbi.nlm.nih.gov/books/bv.fcgi?indexed=goo
gle&rid=hstat1a.section.31343
Yeo, S L; NICU Update: State of the Science of NEC
Journal of Perinatal & Neonatal Nursing. 20(1):46-50,
January/March 2006.
Czervinske & Barnhart Perinatal Pediactric Respiratory
Care. 2nd edition. 2003 Saunders
Pietz, J et al J. Prevention of NEC in preterm infant [20year study] American Accedmeny of Pediatric
http://pediatrics.aappublications.org/cgi/reprint/peds.2
006-0521v1.pdf
References:
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The Experiences of Fathers of Children with Disabilities,
Ruth Soult, Advocacy West Lancs,1998.
Urbano, R C., Hodapp, R M. Divorce in Families of
Children With Down Syndrome: A Population-Based
Study American Journal on Mental Retardation Volume:
112 Issue: 4 Pages: 261-274
2000 USA census:
http://www.census.gov/population/www/socdemo/hhfam.html
Hodapp, RM KrasnerDFamilies of Children With
Disabilities: Findings From a National Sample of EightGrade Students Execeptionality 1994 Vol 5, # 2 pp. 71-81.
Rosel, R, Lawlis GF; Divorce in Families of Genetically
handicapped/mentally retarded individuals; American
Journal of Family Therapy. Vol 11 # 1 pp. 45-50 Spring
1983.