Nurs 368 Final Exam

genetics

genetics

the study of heredity

genomics

study of whole genomes (an organisms full set of DNA), including genes and their functions

DNA

deoxyribonucleic acid, a self-replicating material present in nearly all living organisms as the main constituent of chromosomes. It is the carrier of genetic information.
adenosin and thymine; guanine and cytosine
basic building block of genes

gene

sequence of DNA that codes for a protein and thus determines a trait
basic units of heredity and basic physical unit of inheritance
passed from parents to offspring and contain information that specifies traits
arranged, one after another, on chromosomes
portion of a DNA strand corresponds to a gene
21,000 genes in the human genome

chromosome

a threadlike structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes.
has a p arm (smaller), centromere, and q arm (longer)

alleles

different versions of a gene

polymorphisms

a common DNA mutation or variation of a gene

epigenetics

the study of environmental influences on gene expression that occur without a DNA change
study of heiritable changes in gene expression or phenotype caused by mechanisms other than changes in the DNA sequence
mechanisms- affected by factors and processes (development, environmental chemicals, drugs/pharmaceuticals, aging, diet)
health endpoints- cancer, autoimmune disease, mental disorders, diabetes

telomere

repetitive DNA at the end of a eukaryotic chromosome
protects end of chromosomes
high stress and illness cause shorter telomeres, decrease with aging

mutation

a random error in gene replication that leads to a change

phenotype

physical characteristics of an organism

genotype

genetic makeup of an organism

congenital

present at birth

gamete

specialized cell involved in sexual reproduction
chromosomes are singular, then pair up to form alleles (one from mother and one from father), either dominant or recessive

somatic

pertaining to the body

haploid

an organism or cell having only one complete set of chromosomes

diploid

containing two complete sets of chromosomes, one from each parent.

autosome chromosome

chromosome that is not a sex chromosome
humans have 22 pairs of autosome chromosomes (44 total chromosomes)

sex chromosome

one of the pair of chromosomes that determine the sex of an individual
xx or xy chromosomes (make up a total of 46 chromosomes

homozygous

having two identical alleles for a trait
dominant- AA, recessive- aa

heterozygous

having two different alleles for a trait
Aa

autosomal dominant trait

phenotype seen if at least 1 of the alleles in the genotype codes for that phenotype (Ex AA or Aa)
usually affected offspring have 1 or both parents affected
mating of 1 affected with an unaffected person results in 50% affected offspring
two affected parents can have unaffected children
males and females equally affected

examples of autosomal dominant traits

familial hypercholesterolemia (1 in 500)
polycystic kidney disease (1 in 500-1000)- adulthood, increase in BP, back pain, blood in urine, UTIs, kidney stones, heart valve abnormalities, aneurysms
neurofibromatosis type 1 (1 in 3500)- cafe alait spots on newborns, neurofibromas, benign
marfan syndrome (1 in 5000)- connective tissue problems, heart, blood vessels, joint problems
achondroplasia (dwarfism) (1 in 15000 to 40000)
huntington's disease (1 in 20000)- may not know they have it until after childbearing years, mental/physical deterioration

autosomal recessive trait

phenotype seen only if both alleles in the genotype code for that phenotype (Ex- aa)
the traits of the recessive gene are present when both alleles (genes) in a pair are recessive
a person who has only one recessive allele for a disorder is considered a carrier
carriers do not show signs of the disorder

tay sachs disease

autosomal recessive disorder
ashkenazi jews, 1 in 3600 AJ people, 1 in 360,000 non-AJ
patient dies by 2-4, motor development, loss of all voluntary movement
visual deterioration, seizures, no cure

cystic fibrosis

autosomal recessive disorder
more common in whites
1 in 2500-3500 children
frequency of carriers is 1 in 22
damage to lungs, sticky thick mucous
damage to organs

other autosomal recessive disorders

albanism- complete lack of melanin
phenylketonuria (PKU)- newborn screen, increased level of fetal alinine, intellectual disability
galactosemia- body processes galactose, leads to failure to thrive, liver failure, jaundice
sickle cell anemia
beta thalassemia
congenital adrenal hyperplasia
familial mediterranean fever

sex-linked traits

traits that are inherited with sex chromosomes
males affected much more often than females
daughters of affected males are carriers and will produce 50% affected sons
mothers of affected sons will sometimes have other affected males in her family

examples of sex linked traits

hemophilia (factor VIII)
duchenne muscular dystrophy- most severe, muscle wasting, cardiomyopathy, only live to 20s
color blindness

single gene inheritance disorders

DNA changes in one particular gene
categorized as dominant, recessive, or x linked

multifactorial disorders

conditions caused by interactions among one or more genes and the environment
present and detectable at birth, isolated defects
nature vs nurture? both
also called 'complex' inheritance/disorders
genetic predisposition or susceptibility
disorders do not follow one of the mendelian patterns, they run in families
combined effect of the genetic (and epigenetic) susceptibility and environmental factors
ex- cleft lip/palate, clubfoot, CHD, hydrocephaly, NTD, pyloric stenosis, alcoholism, Alzheimers, cancer, MS, parkinsons, etc

teratogens

agents, such as chemicals and viruses, that can reach the embryo or fetus during prenatal development and cause harm
ionizing radiation
hyperthermia
other maternal disorders such as diabetes or PKU
malnutrition
TORCH infections- toxoplasmosis, other (hep B, varicella), rubella, cytomegalovirus, herpes simplex
alcohol and tobacco- increased risk of SIDS

mendelian inheritance of traits and disease

caused by mutation/polymorphism in genes
occur in fixed proportions with certain matings
two alleles for each gene (one from dad and one from mom)

numerical abnormalities

trisomy- one extra copy of a chromosome
monosomy- one missing chromosome, incompatible with life with autosomes
polyploidy- one or more extra sets of chromosomes (69 or 92), incompatible with life a common cause of miscarriages

trisomy 21

down syndrome
incidence 1 in 800
most common genetic cause of moderate mental retardation

trisomy 18

edwards syndrome
incidence 1 in 5000
die usually within the 1st year of life, intellectual disabilities

trisomy 13

patau syndrome
incidence 1 in 16000
days to weeks to live

structural abnormalities

occur in about 1 in 375 newborns
parts of chromosome may be deleted, duplicated, or rearranged (translocation)
may be caused by exposure to chemicals, radiation, viral infections
causes variety of physical and mental abnormalities
ex- cri-du-chat syndrome and fragile-x syndrome

klinefelter syndrome

XXY
male genitalia, gynecomastia
average IQ 10-15 points lower than siblings
long limbs, tall/slim
hypogonadism, infertility
1 in 500 to 1000 newborn males
hypospadias- meatus below penis, micropenis
decrease in testosterone

turner syndrome

45 chromosomes, X
short stature, webbed neck, extra skin folds
gonadal dysgenesis, infertility
early loss of ovarian function, won't go through puberty
heart and kidney abnormalities
normal intelligence
1 in 2500 newborn girls

prenatal genetic testing options

noninvasive prenatal genetic testing- fetal DNA in maternal serum, done at 10 weeks, results in 5 days
ultrasound/first trimester at 11-13 weeks- ultrasound plus maternal serum tests
maternal serum AFP- 15-20 weeks
triple or quad screen- 15-16 weeks
chorionic villi sampling- 10-12 weeks
genetic amniocentesis- 14-20 weeks

postnatal genetic testing

complete family history- pedigree
careful physical assessment of the newborn
labs- chromosome analysis/DNA studies, genetic disease testing, antibody titers for infectious teratogens (TORCH)

indications for genetic counseling

known/suspected genetic disease in family
maternal age > 35/paternal age > 40
exposure to teratogens
recurrent pregnancy loss
abnormal results on ultrasound, or prenatal screening tests

role of genetic counselor

discusses..
likelihood of developing a disease
how the disease will be expressed
impact of the disease on individual/family
options in regards to treatment, prevention
anticipated future developments

ethical issues in genetic testing

informed consent
genetic testing- preimplantation genetic diagnosis of embryos, prenatal testing
privacy of genetic info- duty to warn, employer figures in out and healthcare costs increase
misuse of genetic info- employment discrimination
genetic screening- carrier screening, newborn screening, stigmatism, privacy, coercion

role of the nurse in genetics

provide information (about testing/disorders)
refer to resources (genetic counseling, websites about disorder)
help clarify options
encourage couple to share feelings
refer to support group if appropriate

at-risk newborns

no prenatal care
exposure to environmental dangers
preexisting maternal conditions
maternal factors
pregnancy related medical conditions
pregnancy complications
labor complications

initial assessment for high risk newborn

term gestation?
clear amniotic fluid?
# of babies
any other risk factors after delivery
breathing or crying?
good muscle tone?

preterm infants

born prior to the completion of the 36th week
#2 cause of neonatal mortality in US
very premature- <32 weeks
premature- <37 weeks
late premature- 34-36 6/7 weeks
low birth weight- <2500 g (5 lb 8 oz)
very low birth weight- <1500 g (3 lb 5 oz)
extremely low birth weight- <1000 g (2 lb 3 oz)

late-preterm infants

born between 34-36 6/7 weeks regardless of birth weight
honeymoon phase- fine for first few hours then have problems
thermal instability
feeding problems- not initiating birth weight, dehydrated, high bilirubin
respiratory distress- underdeveloped lungs
hypoglycemia/jaundice

postterm infant

delivery after 42 weeks gestation > 4000 g
cause unknown
postmaturity syndrome occur sin about 5% of postterm infants- decreased placental functioning
complications- cephalopelvic disproportion, shoulder dystocia, meconium aspiration

postmaturity syndrome

skin dry, cracked, peeling
calcifications of placenta
oligohydramnios- decreased blood flow to kidneys, baby isn't peeing so fluid decreases
starved appearance
hypoglycemia
meconium aspiration syndrome
polycythemia- thick blood bc of increased RBC from hypoxia
congenital anomalies
seizures
cold stress- can't maintain temp, sign of distress

nursing care for postterm infant

maintain a neutrothermal environment
meconium staining
respiratory distress, meconium aspiration syndrome
early and frequent feedings
labs- blood glucose within 15 min, hematocrit increased with polycythemia
monitor daily weights and i/o
administer oxygen as ordered PRN
meconium aspiration syndrome warrants NICU

ballard tool

used to assess gestational age, characteristics of a health newborn
results are +/- two weeks
also length, weight, chest circumference
neuromuscular- posture, square window, arm recoil, popliteal angle, scarf sign, heel to eat
physical- skin, lanugo, plantar surface, breast, eye/ear, genitals

small for gestational age

< 10%
intrauterine growth restriction (FGR)
symmetric- from the beginning of the 1st trimester through pregnancy, all three (height, weight, head circ) falls below 10%; chronic maternal conditions, chronic infections, substance abuse, fetal chromosomal abnormalities
asymmetric- preeclampsia, not apparent until 3rd trimester, just weight is below 10%
IUGR- maternal/placental/fetal factors
maternal risk factors- poor prenatal care, multiple gestation, diabetes, HTN, drugs
placental factors- infarcted placenta, previa, cord prolapse
fetal factors- torch, genetic errors

SGA complications

intrauterine asphyxia cesarean delivery more likely
meconium aspiration syndrome- stress can cause relaxation of anal sphincter
hypothermia and hypoglycemia most common
hypocalcemia and magnesium from mom's chronic condition
polycythemia

IUGR contributing factors

maternal-parity, multiple gestation, smoking, no prenatal care, age, malnutrition in last trimester
maternal disease- heart disease, substance abuse, PKU, HTN, diabetes
environment- high altitude, x-ray exposure, toxins, prescription drugs
placental size, abnormal cord insertion, placental previa
fetal congenital infection, female sex, chromosomal abnormalities

nursing care for SGA

assess for respiratory distress, meconium staining on fingers/umbilical cord, daily weights/pain, feeding intolerance
maintain neutral thermal environment- swaddled baths
parental involvement
frequent feedings
lab tests- blood glucose, hematocrit, calcium, NA

appropriate for gestational age

between 10th and 90th percentile

large for gestational age

weight above the 90th percentile
risk factors- diabetic mother, multiparous mother, genetic disposition, males, certain genetic disorder
complications- birth trauma r/t CPD, shoulder dystocia (asphyxia, fractured clavicle, humerus), hypoglycemia, respiratory distress, polycythemia, increase in oxytocin for induced births, increase in c/s birth rate

complications of premature birth

respiratory distress syndrome
bronchopulmonary dysplasia/chronic lung disease
retinopathy of prematurity
patent ductus arteriosus
necrotizing enterocolitis
sepsis
disrupted nutrition
at risk for cardiovascular, metabolic, neurologic, and thermal dysregulation

respiratory distress syndrome

lack of surfactant/underdeveloped alveoli
causes atelectasis, very common in premature infants

surfactant

brands- survanta, exosurf, infasurf, curosurf
decreases surface tension
decreases work of breathing
decreases leak of proteins and water which leads to pulmonary edema
decreases atelectasis
increases alveolar stability on expiration
administer only through ETT, delay suctioning for at least an hour

s/s of respiratory distress syndrome

retractions
grunting
nasal flaring
tachypnea/apnea
decreased breathing sounds
crackles, rales
cyanosis/pallor
tachycardia
hypothermia
hypoglycemia
hypotonic
hypoxia and acidosis
xray is definitive diagnosis

nursing care for respiratory distress syndrome

maintain thermoregulation
pulse ox
maintain PaO2 > 60 mmHg, follow O2 target sats
use warmed and humidified O2 either by head hood, cannula (low, high flow), mask, pressurized ventilation (CPAP/bubble CPAP, mechanical ventilation, high frequency oscillator
give surfactant up to 3x
monitor blood gases
medications- risk for infection
nutritional support

measurement of lung maturity

phosphatidylglycerol (PG)- present in amniotic fluid, 2-6 weeks term delivery
lecithin and sphingomyelin- L/S ratio 2:1
>2 has good chance
< 1.5, baby will probably need surfactant

neutral thermal environment

higher proportionate body surface area
cannot sweat or shiver
decreased brown fat
cold stress
management- radiant warmer, decrease insensible losses, mist tent, saran wrap, hat, heated mattress

nutritional requirements for preterm

decreased sucking ability- gavage feedings, check gastric residual
decreased digestive enzymes
decreased gastric motility
caloric needs 100-120 cal/kg/day, 24 cal/oz
breastmilk/donor milk
TPN vs enteral
nutrition as immune therapy
should be gaining 15-20 g/kg/day
readiness to nipple feed- RR < 60, rooting, sucking, tolerates holding, gag reflex

patent ductus arteriosus

s/s- murmur, active precordium, wide pulse pressure (S-D), bounding pulses, tachycardia (180-200)/tachypnea (>60)
dx- echocardiogram
tx- indomethacin (BUN and platelets affected), surgical ligation, may not do anything

bronchopulmonary dysplasia

chronic lung disease
cause- mechanical ventilation scars lungs, prolonged oxygenation
s/s- retractions, wheezing, rales, rhonchi, hypoxia, bronchospasm, edema, decreased urine output, weight gain, respiratory acidosis
dx- chest x ray, infiltrates/lung hyperinflation, cardiomegaly
tx- blood gas monitoring, bronchodilators, corticosteroids, diuretics, oxygen therapy, CPT, monitor i/o, nutrition, daily weights

neurological problems in preterm

vessels in head are so fragile, cold can make vessels burst
high risk for IVH (intraventricular hemorrhage)- head u.s at 7-10 days if < 32 weeks, h/h, blood transfusion, head circumference
hypoxia
periventricular leukomalacia
can have grade II on one side and grade III on the other
grade I and II typically resolve
grade IV is more severe, hydrocephalus and needs shunt
happens within 7-10 days, position head midline for 72 hours

necrotizing enterocolitis

gastrointestinal disease- inflammation and necrosis of the bowel
s/s- apnea and bradycardia, increased feeding residuals/emesis, heart rate abnormalities, low BP, abdominal redness, distension/bowel loops, tenderness, blood in stool, pneumatosis (air in abdomen)
APGAR <5/5 shouldn't feed bc it could cause NEC
dx-abdominal x-ray (serial)
labs- CBC with diff, CRP, blood cx, electrolytes, blood gases, coags
tx- gastric decompression, NPO (for 10 days or until xrays are better, then go slow), antibiotics, IV fluids, monitor i/o, potential surgery (colostomy/short gut)

retinopathy of prematurity

extremely low birth weight
sensory impairment
oxygen is damaging, don't resuscitate at 100% (30% better)
retina is not completely vascularized- fluid leakage/bleeding cause scar tissue damages the retina
classifications of ROP- stages 1-5, 5 is retinal detachment
evaluation- eye exams, neonates born before 30 weeks gestation to see if retina is mature, 4-6 weeks of age (repeat weekly until mature)
tx- target sats for oxygen, laser, cryotherapy, vitreoretinal surgery
eye exam prep- dilate eyes with drops, sucrose, containment, cover eyes after

transient tachypnea of the newborn

delay in absorption of fetal lung fluid by pulmonary capillaries and lymph vessels in term baby
tachypnea- soon after birth, 60-120 bpm
resolves 1-3 days
possible predictors- c/s without labor, precipitous delivery, male, perinatal asphyxia, maternal diabetes, asthma
retractions, nasal flaring, grunting, mild cyanosis, similar to resp distress
dx- chest xray
tx- admit to NICU, oxygen and gavage feedings bc breathing is too fast and risk for aspiration, IV to supplement feedings, NPO if >100 bpm

meconium aspiration

meconium stained amniotic fluid
relaxation of anal sphincter and gasping from asphyxia and acidosis
meconium aspiration syndrome- chemical pneumonitis (obstruction and air tripping, meconium adheres to lungs)
s/s- tachypnea, cyanosis, grunting, rales, retractions, barrel shaped chest, greenish staining to nails and skin
dx- chest xray for hyperexpansion and atelectasis
tx- vigorous (not invasive, still placed on mom, HR >100, flexed tone, no resp issues), nonvigorous- intubate and suction immediately as soon as head comes out, mechanical ventilation/high freq vent/ECMO, antibiotics
NICU and neonates present for delivery

hyperbilirubinemia jaundice

physiologic vs pathologic
TSB > 5-6
hemolytic disease of the newborn- Rh sensitivity or ABO incompatibility
tx determined by bilirubin result and age of baby in hairs, as well as risk factors
rx- phototherapy, facilitates excretion of unconjugated bilirubin in the bile, bili lights or bili blankets, exchange transfusion to prevent kernicterus
if Tcb > 5, get Tsb

physiologic hyperbilirubinema

> 24 hours
increased RBCs
liver immaturity
delayed feeding
bruising

pathologic hyperbilirubinemia

< 24 hours
Rh or ABO incompatibility
(+ coomb's test)
hydrops fetalis
sepsis
cold stress
blocked bile duct (rare), biliary atresia
risk for kernicterus and bilirubin encephalopathy

hyperbilirubinema treatment

hydration/phototherapy- monitor temps/no lotion, converts to lumirubin
infant with rh disease- treat anemia, remove sensitized RBCs that would be destroyed, remove serum bilirubin, provide bilirubin free albulin
exchange transfusion- 25-48 hours > 20, 49-72 hours > 25, > 72 hours > 25

nursing care for hyperbilirubinemia

expose as much skin as possible, keep under lights except for feedings
frequent feedings is #1 priority
eye protection
frequent diaper changes
monitor i/o
remove eye protection at feedings, promote bonding
check bilirubin levels as ordered- total = indirect + direct

neonatal infections

vertical transmission (at birth) maternal- rubella, CMV, syphilis, HIV, toxoplasmosis
horizontal transmission (after birth) neonatal/environmental- early (72 hours), late (7 days), very late (>3 months)
causes- bacterial (group b strep), viral (torch, toxoplasmosis, syphilis, CMV, hep B, HIV, herpes simplex, varicella zoster, ZIKA), fungal (candidiasis), other

toxoplasmosis

caused by cat litter and gardening in soil

herpes simplex

swab in nose, conjunctiva, rectum to test
not able to maintain BP, affects spleen
tx- acyclovir

chickenpox

tx- vzig, immunoglobulin
30% mortality

group b streptococcus

treat with ampicillin or cephazolin if allergic

syphilis

tx- penicillin
can cause bone/organ damage, blind, nerve, liver, anemia, spleen
stillbirth/neonatal death
asymptomatic
s/s within first 3 months, rhinitis, maculopapular rash

cytomegalovirus

microcephaly, visual impairment, intellectual disability, fetal death, liver problems, deaf
detected in urine
acyclovir

infants with HIV

transmitted transplacentally, during birth or via breastmilk (avoid breastfeeding)
transplacental transfer decreases if mom takes zidovudine during pregnancy
ID infants early- HIV-DNA polymerase chain reaction (PCR) testing at 1-2 months, 4, 6, 18 months
maternal antibodies in infants blood until 15 months
care- administer ZDV to newborn fro 8 hours after birth to 6 weeks at least
assess for- infection, weight gain, failure to thrive, GI problems
use standard precautions
provide standard newborn care

management of neonatal infections

s/s- apnea, bradycardia, hypothermia, retractions, cyanosis, lethargy, poor feed, immature to total neutrophil ratio > 0.20
labs- CBC with diff, blood cultures/urine/CSF, c-reactive protein
dx- positive blood cultures
medical management- antibiotics (min 48 hours, 10-14 days, max 21 days), IV fluids, monitor glucose/electrolytes, ventilation management/oxygenation

infants of diabetic moms

can be LGA/SGA
SGA- vascular complications, reduced placental blood flow
LGA- high levels of maternal glucose
can interrupt surfactant production- babies have a hard time breathing

IDM complications

hypoglycemia- want to be above 40 in 4 hours, 45 in > 4 hours
hypocalcemia
hypomagnesemia
hyperbilirubinemia
birth trauma- fracture clavicle
respiratory distress syndrome (RDS)
congenital birth defects
risk for childhood obesity and type II diabetes
polycythemia- increased Hct (>65%) and RBC, deceased extracellular water not edema, looks 'ruddy'

IDM nursing care

control maternal hyperglycemia prior to delivery
maintain temperature
check infant's glucose after birth and per protocol
feed early if glucose < 40, glucose gel
risk for seizures if below 20, give IV dextrose

maternal substance abuse

alcohol- fetal alcohol syndrome, alcohol is teratogenic
cocaine- developmental delays, prematurity
heroin and methadone- irritability, LBW
tobacco- prematurity, developmental delays
marijuana- LBW

infants of substance abusing mothers

intrauterine drug-exposed infants
withdrawal (prevention is #1)
intrauterine asphyxia
intrauterine infection
alterations in birth weight
low APGAR scores
RDS
jaundice/behavioral abnormalities
congenital anomalies

substance exposed neonate

between 2000-2009 the annual rate of neonatal abstinence increased threefold, and maternal opiate use increases fivefold
4.4% of pregnant women use substances, and 10.8% used alcohol
long term effects are difficult to measure
babies with NAS may show abnormal behaviors for 6-9 months

neonatal abstinence syndrome

symptoms- irritable, tremors (undisturbed or if touched), increased muscle tone, loose stools
scoring
treatment- nonpharm (swaddle, feed, aromatherapy, music therapy, massage), pharm (narcotics)
identified through toxicology screening- cord blood (use from last 2 trimesters), meconium (multiple meconium, last 3-4 months, takes 5 days for results), urine (measures recent exposure, has to be first void), hair

CNS depressants

alcohol
marijuana
quaaludes
barbituates
benzodiazepines

marijuana

tremors
low birth weight, IUGR
increased risk for SIDS with paternal use
long term behavioral issues
long term effects not proven
poly-substance use frequent

semisynthetic opioid/synthetic narcotics

heroin
oxycodone- percodan, percocet, oxytocin
darvon
methadone
vicodin (hydrocodone)
buprenorphine
fentanyl
meperidine (demerol)
tramadol/talwin

heroin

frequently poly-substance abuse
low birth weight
irritable
poor response to caregivers
hyperactive
quicker but more painful withdrawal