Exam 1 Flashcards
1
Q
phases of fetal development
A
pre-embryonic
embryonic
fetal
2
Q
pre-embryonic phase
A
conceptus (blastocyst) migrates from fallopian tube to uterus
- time from fertilization to implantation
- typically 8 days
- independent of environment (not of genetics)
3
Q
embryonic phase
A
weeks 3-8
- period of organogenesis
- germinal tissues form
- heart starts to beat (6 weeks)
- time when malformations occur
- greatest vulnerability to teratogens
4
Q
fetal phase
A
9 weeks - delivery
- further growth, differentiation, and maturation of organs
5
Q
in fetus, when do pulmonary alveoli begin to develop?
A
24 weeks - this is earliest fetus is viable outside of womb (baby will be on ventilation)
6
Q
in fetus, when does surfactant present in lungs?
A
34 weeks - baby can breath on own (alveoli pop open and stay open upon first breath)
7
Q
organogenesis
A
time when all of the tissues are specializing and organs are forming
8
Q
germinal tissues
A
3 cell layers form:
- ectoderm will become skin and nervous system
- mesoderm will become muscle and bone
- endoderrm will become GI tract (alimentary canal), endocrine and respiratory systems
9
Q
membranes around fetus
A
amnion - inner layer
chorion - outer layer
these begin as separate sacs and fuse; contain amniotic fluid
function: protect fetus from injury and infection
10
Q
membranes ruptured vs. membranes intact - acronyms
A
PROM: prolonged rupture of membranes (rupture prior to 18 hours b/f delivery)
- inc risk of infection
PPROM: premature, prolonged ROM (rupture prior to 35 weeks gestation)
SROM: spontaneous ROM (happens on own)
AROM: artificial ROM (OB or midwife ruptures membranes)
- facilitates monitoring; increases force of contractions
11
Q
amniotic fluid - definition and functions
A
watery fluid derived mainly form maternal blood
Functions:
- acts as a cushion for fetus as mother moves
- prevents membranes from sticking to baby
- allows for fetal movement
- necessary for lung development
12
Q
what is the placenta and what is it made up of
A
It is the site of exchange of materials in both directions; acts as the intermediary between the fetus and the outside world
chorionic villi (from fetus) and decide baseless (from mother)
13
Q
chorionic villi
A
fetal contribution to placenta
finger-like projections of chorion which penetrate into the endometrium, the lining of the uterus.
each contains fetal arteriole, venule and capillary
14
Q
decidua basalis
A
maternal contribution to placenta
when chorionic villus invades the endometrium, it causes the maternal capillary beds to break down into sinusoids
- arteriole –> open space –> venule
fetal capillary sits within the sinusoid and is bathed by maternal blood
15
Q
crossing the placenta
A
diffusion of molecules in either direction
Mother to fetus: oxygen, aminio acids, fats, glucose, some hormones, antibodies, most drugs, viruses
Fetus to mother: carbon dioxide, bilirubin, ammonia and other waste products
note: cells and large molecules are unable to pass
16
Q
human chorionic gonadotropin (hCG)
A
a hormone which, along with progesterone, maintains the lush endometrium necessary to sustain pregnancy
produced by placenta
by the end of the second week post-conception, present in sufficient quantity to be detected by assay in maternal blood and urine
- basis for pregnancy tests
17
Q
when does ovulation occur?
A
Ovulation occurs 14 days before menstruation.
Standard cycle length is 28 days; therefore, in standard situation, ovulation is mid-cycle
In longer cycles, ovulations still occurs 14 days before menses, so toward latter part of cycle
18
Q
how to date a pregnancy
A
counting 40 weeks from first day of last menstrual period
- E.D.D. = estimated date of delivery (unreliable for many reasons: recall, cycle length, implantation bleeding)
- notice that the first two weeks of pregnancy actually occur before ovulation and fertilization!
19
Q
role of ultrasound in pregnancy
A
Dating pregnancy
Evaluating anatomy
Checking position of placenta
Checking volume of amniotic fluid (indicator of kidney and resp. health)
two types:
- transvaginal
- transabdominal
20
Q
transvaginal ultrasound
A
Ultrasound probe is inserted into vagina
- useful early on in pregnancy because can get closer to fetus and give more accurate images in first weeks
- disadvantages: can be uncomfortable for mom
21
Q
transabdominal ultrasound
A
Easy to perform
Standard technique
More comfortable
Works best when baby is a bit bigger and bowel is out of way
22
Q
accuracy of ultrasound dating - depends on when it is done
A
First trimester: measure crown-rump length
- accurate +/- 3 days
Second trimester: measure biparietal diameter
- accurate +/- 1 week
Third trimester: biparietal diameter (across top of head)
- accurate to +/- 2 weeks
23
Q
definition of trimesters
A
First trimester: weeks 1 to 12 (13 wks)
Second trimester: weeks 13 to 28 (16 wks)
Third trimester: weeks 29 to delivery (11 wks)
24
Q
definition of “term” pregnancy
A
38-42 weeks
37 weeks – consider no risk
42 weeks – baby gets big; placenta begins to die off
25
importance of blood type / antibody screening
maternal antibodies can cross the placenta
mismatch between maternal and fetal blood types can cause situation where mother makes antibody to fetus’ blood cells
result is hemolysis (destruction) of fetus’ RBCs
- causes jaundice and in extreme, total body edema, a condition known as “hydrops fetalis”
26
ultrasound for anatomic survey
checks babies anatomy
| - best b/t 18-20 weeks since all organs have formed but baby is not too large
27
why perform genetic screening?
Advanced maternal age (35)
Abnormal findings on prenatal ultrasound
Family history of genetic disorder
Previous miscarriages
28
two ways of genetic screening
Amniocentesis: sample of amniotic fluid via insertion of needle into chorionic sac
Chorionic villus sampling: get sample of chorionic sac
- farther from baby, so safer, but only can do for a specific time period
29
glucose tolerance test - done since mom's can get type II diabetes during pregnancy and insulting is a growth factor for babies
Test to assess for maternal diabetes
- fasting blood sugar provides a baseline for comparing other glucose values; pregnant women drink 75 grams of glucose; blood samples will be collected at timed intervals of 1 and 3 hours after patient drinks the glucose.
- elevated blood sugars prompt various treatments: dietary management, oral hypoglycemic agents, insulin
Performed at 16 weeks
30
infection diseases: what and when tested
First prenatal visit: Screens for: Hepatitis B, HIV, Syphilis, Gonorrhea, Chladymia.
-may repeat prior to delivery in high-risk individuals
Screen for immunity to Rubella, usually conferred by vaccine
Group B strep screening at 36 to 37 weeks
31
routine testing of mother (and mothers of specific decent)
Alpha fetoprotein:
- high in neural tube defects
- low in Down Syndrome
Specific to population:
- sickle cell disease
- cystic fibrosis
- “Ashchkinasi screen” for diseases found in people of European Jewish descent
- specific to family, based upon family history
32
malformations
complete or partial absences of a structure caused by environmental or genetic factors
- most originate during the period of organogenesis (3rd to 8th weeks of gestation)
- e.g. congenital heart defect
33
Tetralogy of Fallot
MOST COMMON CYANOTIC CHD
A set of congenital cardiac defects including:
- overriding of ascending aorta over ventricular septum and receives venous as well as arterial blood (due to hole in septum)
- ventricular septal defect
- pulmonic valve stenosis (obstruction of RV outflow) - valve is pushed over and compromised
- right ventricular hypertrophy due to inc. pressure since blood can't get through valve; considered part of the tetralogy although it is reactive to the other defects (syn: Fallot tetrad)
Note: degree of cyanosis depends on degree of stenosis of the pulmonic valve
Note: "boot-shaped" heart
34
deformations
due to mechanical forces that mold a previously normal part of the fetus over a prolonged period
- often musculoskeletal and reversible
- occurs during fetal period (after 9 weeks)
- e.g. clubfoot
35
disruptions
destructive processes which result in morphological alterations of already formed structures
- e.g. limb defects caused by amniotic bands
36
syndromes
groups of anomalies occurring together which have a common cause
- e.g. Stigmata of Down Syndrome are caused by trisomy of chromosome 21
37
associations
groups of anomalies that occur together more often than chance alone would allow but whose cause has not been determined
- e.g. CHARGE association (coloboma, heart defects, atresia choane, retardation of growth and development, genital abnormalities, ear abnormalities)
38
teratogens
agents, generally chemical, radioactive or infectious which can produce birth defects. - especially destructive when exposure occurs during the period of organogenesis (i.e. embryonic period)
39
important influences on pregnancy outcomes - obesity and malnutrition
obesity (BMI>30): infants of obese women have birth weights equal to those of non-obese women but have 30% more body fat, at expense of lean body mass
malnutrition: causes lifelong immunodeficiency, short stature, cognitive impairment; most common cause of low birth weigh babies in developing world
40
key vitamins and minerals during pregnancy
Folic acid: a B-complex vitamin which can reduce the risk of neural tube defects by 70%
Calcium: for bones, teeth, muscle, CNS
Iron: for development of blood cells, CNS
Vitamin D: for bones and teeth
- currently being touted as a panacea– e.g. improved immunity
Vitamin A:
important for development of eyes
- excess can cause major malformations as with isotretinoin (Accutane)
41
diabetes mallitus (DM) in pregnancy
relative or absolute deficiency of insulin secretion which results in hyperglycemia in mother - all 3 types (gestational, type I, and type II have same effect on fetus)
- Insulin does not cross the placenta
- Glucose diffuses freely across the placenta
- baby makes a lot of insulin to regulate high glucose load
- insulin acts as a powerful growth hormone in fetus, causing macrosomia
- excessive insulin results in risk of hypoglycemia in the newborn period
42
macrosomia
large growth of fetus; caused by large levels of insulin which acts as a growth hormone for fetus
43
effects of excessive glucose in 1st trimester
teratogenic - can cause caudal regression syndromes (malformations of hips & legs)
44
effects of thyroid disease on fetus
Hyperthyroidism in mom is usually Grave’s disease, a condition in which mom makes an antibody which stimulates thyroid hormone production
- can cause growth retardation or prematurity in newborn
Hypothyroidism
- treated, does not affect the fetus (synthroid)
- untreated, can cause decreased IQ, small stature
45
hypertension (HNT)
can predate pregnancy or be pregnancy-induced (PIH)
46
pre-eclampsia
HTN (hypertension) which generally begins third trimester and is associated with edema (maternal) and proteinuria
47
eclampsia
same features as pre-eclampsia with addition of maternal seizures
48
HELLP syndrome
severe form of HTN associated with hemolysis, elevated liver enzymes, low platelets
49
risks of HTN to mom and baby
mom: stroke
baby: primarily related to insufficient blood supply to the placenta (because of vasoconstriction)
- IUGR (intrauterine growth restriction)
- premature delivery
50
risks of extreme youth pregnancy
defined as
51
risks of advanced maternal age pregnancy
defined as > 35 yrs; risks inc with age
- Down Syndrome
Note: CHD much more likely in babies with Down Syndrome - all Down Syndrome baby's get echocardiograms!
52
medications used by mother
as a rule, they cross placenta
if possible, stop all prior to conception
53
risks of anticonvulsants used by mom - 20-35% of woman with seizure disorders have an increase in seizures during pregnancy
Dilantin (phenytoin) is associated with “fetal hydantoin syndrome”, consisting of cleft lip and palate as well as mental retardation
Valproic acid is associated with neural tube defects (eg. Spina bifida)
Keppra has had limited study but no teratogenicity
Lamictal .9% (8.9/1000) incidence of cleft lip +/- palate
54
risks of psychotropic medications used by mom
Lithium, used to treat bipolar illness, risk of Ebstein anomaly (displacement of tricuspid valve into right ventricle)
Phenothiazines, older anti-psychotic meds (eg, Haldol and Thorazine) had no known teratogenic effects but had disagreeable side-effects for the adult patient
Newer antipsychotics’ effects are unknown but they certainly cross the placenta (e.g. Seroquel)
SSRIs antidepressants which are currently first-line
55
risks of antidepressant use by mom - pregnancy can increase depression, so not best time to stop medication use
Tricyclics: amitriptyline and nortriptyline are older and known to be safe
Selective Serotonin Uptake Inhibitors (SSRI): fairly safe
- Celexa, Prozac, Zoloft all safe
- Avoid Paxil- doubles risk of septal defects in fetus
- Wellbutrin: OK
56
risks of general anesthesia, surgery, and x-rays during pregnency
General anesthesia: not teratogenic
Surgery: can be safely performed on MOC during pregnancy
XRays: known to cause microcephaly, spina bifida, cleft palate, and limb defects
57
risks of tobacco use by mom
IUGR: most common cause of IUGR in developed contries
spontaneous abortion
prematurity
perinatal mortality
SIDS
58
risks of marijuana use by mom
associated with IUGR
long-term side effects controversial: may cause measurable cognitive impairment
mild neurological abnormalities (jitteriness and irritability as newborn)
59
risks of opiate use by mom (includes narcotics)
This group of drugs includes narcotics
- Prescription: fentanyl, oxycodone, methadone, morphine
- Non-prescription: heroin
Acute intoxication at delivery can cause respiratory suppression
Babies are likely to be born dependent and exhibit signs and symptoms of withdrawal, requiring methadone taper
60
risks of cocaine use by mom
prematurity, among many other things (mainly cognitive and behavioral problems, but no motor defects)
61
risks of amphetamine (meth) use by mom
microcephaly, cleft lip and palate
most prevalent problem = neglect
62
risks of alcohol use by mom - 3 major components of fetal alcohol syndrome
Prenatal and postnatal growth deficiencies
Microcephaly associated with cognitive impairment
Typical facies: short palpebral fissures, indistinct philtrum, thin upper lip
63
APGAR Score
reported 1 and 5 minutes after birth; most effective for term babies; expression of infant's physiological condition and includes subjective components
A: appearance
- blue or pale = 0
- acrocyanotic (hands, lips blue) = 1
- pink = 2
P: pulse (HR) 80-160 BPM
- absent = 0
- 100 = 2
G: grimace / reflex irritability (responce to stimulation)
- none = 0
- weak response to rub = 1
- active withdrawal or cry = 2
A: activity (tone)
- limp = 0
- some flexion = 1
- active motion = 2
R: respiratory, 30-60 breaths/min
- absent = 0
- weak cry/hypoventilation = 1
- good, crying = 2
64
labor
process by which products of conception (baby, placenta, cord and membranes) are expelled from the uterus
- requires thinning and dilation of cervix, resulting from rhythmic contractors of uterine muscles
- note: contractions w/o cervical changes does not meet definition of labor
65
changes in labor definitions (2014) to limit c-sections
allowing most women with low-risk pregnancies to spend more time in the latent or early phase of the 1st stage of labor
- changing the definition of active labor to start at 6 cm.
allow for more time in the second stage or pushing stage of labor
- first time Mom’s are now routinely able to push for 3 or more hours before the second stage is considered prolonged
66
normal HR for fetus - fetal monitoring
HR: 120-160 (done with internal monitor in baby's scalp - tells us membranes have been ruptured)
1st stage of labor: fetal HR increases with contractions
second stage of labor: fetal HR decreases with contractions (due to head compression and stimulation of vagus nerve)
note: deceleration of HR after contractions are abnormal and indicate stress on fetus
67
epidural
goal is to provide analgesia not anesthesia
risks: short-term backache, puncture headache, hypotension, maternal fever, prolonged labor, and increased rate of instrumental delivery
- do not increase a mother’s risk of delivering by cesarean
- current recommendations: placement of epidural at maternal request regardless of cervical dilatation.
68
EnCaul
baby delivered with membranes intact
69
three types of operative delivery and risks of each
Cesarean section: - retained lung fluid
- laceration of the fetus
- surgical complications
- prolonged recovery for mom
Forceps assisted birth:
- skull fractures (rare)
- facial nerve palsy (heals quickly / good prognosis)
Vacuum assisted delivery: shearing forces on the scalp
- subgaleal hemorrhage: large potential space where baby can bleed out (extradural hemorrhage) - why we say these can be dangerous (shock)
- cephalohematoma: collection of blood within periosteum; blood does not cross suture lines (can also get from pounding)
- caput: edema (fluid filled area of scalp; fluid will move with changes in position)
- damage to skin
70
birth positions
```
occiput anterior (OA): head first, face down
- most common
```
```
occiput posterior (OP): head first, face up; largest surface area of the skull presents
- more likely to need operative intervention
```
transverse lie: baby is sideways
- incompatible with vaginal delivery
breech: buttocks are delivered before the head
71
recommendations for babies in breech position
dependent on experience of health care provider (c-section will be the preferred mode of delivery for most physicians because of the diminishing expertise in vaginal breech delivery)
Obstetricians should offer and perform external cephalic version
- attempt to turn baby by manipulating fetus from outside of mom's abdomen
72
transitional period for newborn
first few hours after birth; period of many changes in the physiological makeup of the newborn, including conversion of cardiac and pulmonary systems to extrauterine life
73
normal newborn vital signs
Temperature: 36.5-37.5°C (axillary)
Heart rate: 120-160 beats/min
Respiratory rate: 30-60 breaths/min
Blood pressure: 60/40 (rarely take in newborn)
74
periodic breathing of infants
infants exhibit periodic breathing or bursts of rapid breaths, slowing, then rests for
75
preventative care of newborn: medications and vaccination
3 interventions given within 2 hours of birth (eyes and thighs):
1. Eye prophylaxis with 0.5% erythromycin ophthalmic ointment
- helps to prevent gonorrhea (good) and chlamydia (so, so)
2. Hepatitis B Vaccine (mom can decline)
3. Vitamin K: 1 mg IM (orally)
- prophylaxis against early and late Vitamin K Deficiency Bleeding (VKDB)
76
definition of neonate
period of birth to 28 days old
77
anatomy of heart
4 chambers
2 upper are atria (singular atrium)
2 lower are ventricles
Septa (singular: septum) are muscular walls which divide the sides
4 valves:
Tricuspid: between the right atrium and right ventricle
Pulmonary: between right ventricle and pulmonary artery
Mitral: between left atrium and left ventricle
Aortic valve: between left ventricle and aorta
Major vessels:
Inferior and Superior Vena Cava: largest veins in body, bring blood back from systemic circulation to right atrium & then ventricle
Pulmonary artery: takes deoxygenated blood from right ventricle to lungs- note branches
Pulmonary veins: return oxygenated blood from lungs to left atrium
Aorta: takes oxygenated blood to systemic circulation
78
neonatal circulatory shunts
Since fetus does not use lungs to breath, shunts take blood away from lungs to placenta; shut off upon birth
Note: pressure on right side is higher in fetus
Ductus arteriosus: shunt between pulmonary artery & aorta, has no valves so blood can flow each direction
Umbilical arteries: branches of common iliac arteries that take blood to placenta
Umbilical vein: from placenta to liver or DV
Ductus venosus (DV): option to bypass liver, direct to IVC since placenta filters blood
Foramen ovale: interatrial shunt from RA to LA
Functional shunt: increased pulmonary pressure so most blood goes to body and not lungs (10-20% to lungs) - rt sided pressures are higher than lt sided pressures
79
how shunts are shut off at birth
Umbilical arteries are cut at birth, which cut supply to umbilical veins and ductus venosus
Ductus arteriosus closes within 24-48 hours due to increased in PO2 and decrease in prostiglandins
Foramen ovale is shut off due to pressure change (pressure increases on left side)
80
partial pressure of oxygen
partial pressure of any gas is a measurement of how much gas there is in any environment (e.g. liquid, room of air)
- changes with altitude
- changes in fetal lung during transition
81
percent saturation
% saturation of oxygen in air is 21% regardless of altitude
- the number of molecules of oxygen are fewer as altitude increases but the percentage of oxygen molecules to total molecules in air is always 21%
% saturation of oxygen in blood - percentage of red blood cells are carrying oxygen
- measured by a pulse oximeter
- this can change with blood
82
percent saturation after transition
should be greater than 95%
83
how can you trust you have an accurate pulse Ox reading
wave-forms on machine and pulse matches the one you took
84
pressure changes during transition and effects on shunts
Increase in pO2 in blood when baby begins to breathe air
- dilatation of vessels in pulmonary bed drops pulmonary pressures; therefore, right sided pressures become lower than left (functional shunt gone)
- constriction (closure) of ductus arteriosus
Systemic pressure increases as a result of cutting off umbilical circulation (to and from placenta) with result of increased volume elsewhere
Foramen ovale: pressure effect of having LA pressures greater than RA pressure
Ductus venosus closes because there is no longer flow through it
85
cardiac cycle
Systole
- time from onset of ventricular contraction until closure of aortic and pulmonary valves
- begins with first heart sound- closure of tricuspid and mitral valves
Diastole
- time of filling of chambers
- time between second and first heart sounds
86
congenital heart disease (CHD) - types
most common congenital malformation in newborns with at least 35 variations
Critical congenital heart disease: requires intervention in first 28 days
Serious congenital heart disease: requires intervention in 1st year
87
how does CHD present in a newborn
Although there are a variety of possible lesions, CHD presents in only a few ways:
- Cyanosis
- Heart failure (or its extreme, shock)
- Cardiac murmur
88
cyanosis in newborn - two types
central: lips, inside of mouth / mucous membranes, chest
- serious; most don't notice cyanosis until pulse ox is low (84)
acral: fingers, toes, perioral
- not serious; reflects perfusion rather than oxygenation
89
two cardiac-related (CHD) causes of central cyanosis
Decreased pulmonary blood flow caused by improper closing of shunt
Mixing of oxygenated and deoxygenated blood in heart (fixed mixing lesions)
90
cyanosis - main causes
Primary lung diseases such as pneumonia, respiratory distress syndrome, meconium aspiration, etc.
Airway obstruction
Hypoventilation (drug induced or neurologic)
Polycythemia
Congenital heart disease
91
cyanosis: pulmonary vs. cardiac
pulmonary:
- labored breathing
- improves with 100% oxygen supplementation
- cyanosis often improves with crying
cardiac:
- non-labored respirations
- no or minimal response to 100% oxygen
- cyanosis worsens or doesn’t improve with crying
92
hyperoxitest
Most sensitive tool for differentiating between primary pulmonary and cyanotic congenital heart disease
- measure pO2 by blood gas in room air
- place baby on 100% oxygen for 10 minutes, then re-check blood gas
- note: pulse ox often used, easier but less accurate
Results: a patient with primary pulmonary disease will usually dramatically increase saturation when given oxygen; cardiac etiology will have no improvement
93
symptoms of CHF in newborn
Increased left atrial pressure causes pulmonary vascular congestion and pulmonary edema
- tachypnea results from vascular congestion and edema (lungs are stiff and wet)
- tachycardia results from low cardiac output
Hepatomegaly reflects increased pressure in the right atrium
Sweating and feeding difficulties are common
May be cyanotic or not, depending on degree
94
newborn murmurs and how to describe them
cardiac murmurs are very common; must distinguish innocent from pathologic!
Description:
- intensity
- timing in systole or diastole
- quality
- location
- transmission
95
how to grade intensity of a cardiac murmur
6 point scale
1. Barely audible
2. Soft but easily audible
3. Moderately loud, but without thrill
4. Louder and associated with a thrill (palpable palpation on chest)
5. Audible with stethoscope barely on chest
6. Audible with stethoscope off the chest
96
how to describe quality of murmurs / character of sound
Innocent murmurs are described as “vibratory” or “musical”
Ventricular septal defect (VSD) is high-pitched and blowing or coarse
- shows up later since depends on changes in pressure
```
Aortic stenosis (AS) & Pulmonic stenosis (PS) described as “grating”
- hear at birth since due to valve defects that are not affected by changes in pressure
```
97
ejection type murmurs
you can distinctly hear S1 (closing of the tricuspid and mitral valves), then the murmur, then S2
caused by flow through stenotic or deformed semilunar valve (aortic or pulmonic)
Also called “crescendo-decrescendo”
98
regurgitant murmurs
you can’t separate the murmur from S1
caused by flow of blood from a chamber that is at higher pressure to one of lower pressure - big hole and blood flowing back and forth
(e.g. VSD)
99
benign murmurs (3 common) - common during transition / closing of shunts
Pulmonic flow murmur or “peripheral pulmonic stenosis”
Physiologic ductus arteriosus
Tricuspid Jet
100
pulmonary flow murmur - newborn
most common / benign
also known as “peripheral pulmonic stenosis” or PPS
101
ways to evaluate newborn
fetal echocardiogram: only most severe cases of CHD can be determined (more accurate at 18-20 weeks)
- most useful for congenital heart lesions, but every expensive!
blood pressure (4 limbs): difference b/t rt arm and leg is indication for coarctation of aorta
pulse oximetry (done as screening test; baby can be low on O2 saturation even if color is good)
chest x-ray: useful for signs of CHF (enlarged heart or pulmonary edema)
102
polycythemic (aka erythrocythemia)
increase in the total red blood cell mass of the blood
| - baby with this disorder looks for cyanotic than an anemic baby at same saturation
103
transposition of great vessels
serious condition where aorta comes out of right ventricle and pulmonary vein comes out of left ventricle; thus, un-oxygenated blood in going through body and oxygenated blood in a closed circuit through lungs
- two independent circuits that do not support life (note: ok in utero, but deadly at birth)
- note: "egg on a string" shaped heart
104
two types of neonatal CHD
1. Obstruction to the flow of blood in the heart or great vessels caused by underdevelopment of structures
Valves, ventricles, vessels
- Valvular atresia/stenosis
- Hypoplastic left or right heart syndromes
- Coarctation of the aorta/interrupted aortic arch
2. Blood flows in abnormal patterns
Through septal defects, abnormal communications
- From right to left (blue mixes with red)-leads to cyanosis
- From left to right (red mixes with blue)-leads to CHF
105
most common cardiac lesions in newborn (cyanotic vs. acyanotic)
Cyanotic - 5 T's with a P and H
- Transposition of the great vessels
- Truncus arteriosus (single arterial vessel arises from heart, instead of separate aorta and pulmonary artery)
- Tricuspid atresia (absence of tricuspid valve on rt side of heart)
- Tetralogy of Fallot
- Total anomalous pulmonary venous return (TAPVR) (pulmonary viens do not empty into LA)
- Pulmonary atresia / stenosis (passage is closed, narrow, or absent)
- Hypoplastic left heart
Acyanotic
- Patent ductus arteriosus
- Large septal defects
- Critical aortic stenosis
- Coarctation of the Aorta
- Hypoplastic left heart
106
patent ductus arteriosus
acyanotic heart lesion; ductus arteriosis, b/t pulmonary artery and aorta, remains open
- blood flows from aorta to pulmonary arteries to lungs = pulmonary edema (due to higher pressure now in aorta)
typically closes within hours to days of birth
most frequent disorder in premature babies
107
ventricular septal defects (VSD)
acyanotic heart lesion
MOST COMMON CHD
hole in either atrial or ventricular septum; blood will flow in direction of greatest to least pressure, which changes from fetus to newborn
note:
- if on own, will not present with hypoxia since blood goes form lt to rt and to lungs to get oxygenated
- if part of tetralogy of fallot, this is a mixing lesion that presents with hypoxia
108
longterm risk of un-treated VSD
Eisenmenger's complex: pulmonary vascular disease (hypertension) with continued pulmonary over circulation
109
coarctation of aorta
acyanotic lesion - narrow area of aorta results in impaired left ventricle output, decreased pulses, differential BP
Early presenting: when DA closes in few days, drastic presentation of shock, renal failure
- prostaglandins (IV): temporary life saver (open ductus)
- requires surgery once baby is stable
Late presenting: around age of 5, patient has weakness/fatigue in legs
- requires surgery, but not emergency
110
basis CHD therapies - summary
Prostaglandin E1--keeps ductus arteriosus open
- crucial in left-sided obstructive lesions & lesions with decreased pulmonary blood flow
Diuretics--improve pulmonary edema
Inotropic agents--improve cardiac contractility
- dopamine, dobutamine, digoxin
Oxygen--increases pulmonary blood flow, alveolar oxygen delivery
Catheterization--can open valves, atrial septum with balloon
Surgery--various shunts and repairs
111
normal respirations during transition
RR: 40-60
periodic breathing
pO2>85%
- after transition pO2>90%
112
tachypnea
increases rate of breathing (> 60 BPM)
MOST SENSITVE INDICATOR OF LOWER AIRWAY DISEASE
- tachypnea combined with retractions = inc. "work of breathing" - since each breath provides less o2, baby compensates by breathing quickly
113
audible noises - indicating respiratory distress
Grunting or Singing
- low or high-pitched sounds on expiration
- reflect baby’s attempt to keep air in lungs to prevent collapse
Stridor
- inspiratory sound
- obstruction of middle airway
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auscultory noises -indicating respiratory distress
Crackles or rhales
- inspiratory sounds
- reflect fluid in the air-spaces
- rhales: sounds like rubbing hair in front of ears
Wheezing or rhonchi
- high or low pitched sounds on expiration (inspiration when severe)
- reflects air trying to escape past obstruction in middle airways
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percent saturation - acceptable levels at birth / transition
```
2 min 60%
3 min 70%
4 min 80%
5 min 85%
10 min 90%
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All neonates take time to clear lung fluid
- tolerate sats of 85 to 87% for the first few hours of life - if baby is otherwise asymptomatic
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pulmonary disorders in newborns
MOST COMMON cause of respiratory distress in newborns
1. Upper airway obstruction
2. Lower airway obstruction
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upper airway obstruction
Nasal stuffiness - newborns are OBLIGATE nose breathers
Choanal Atresia - back of nasal passage blocked
- presents with cyanosis at rest and pink with crying
Masses
Micrognathia (gnath = jaw)
Laryngeal or Tracheal Obstruction (middle airways)
- floppy airway is the MOST COMMON cause of middle airway obstruction
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lower airway obstruction
If suspect lower airway disease, get a CHEST X-RAY
Aspiration - process of drawing breath
- meconium, amniotic fluid, maternal blood
Hyaline membrane disease (aka respiratory distress syndrome)
Pneumothorax - collapse of part or all of lung
TTN (transient tachypnea in newborns) - results from retained fluid in lung (aka RFLLS)
- supportive O2 care for few days
Pneumonia: neonatal systemic infections (bacterial or viral) - group B strep, etc.
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normal transition in lungs
hormonal changes associated with labor cause fluid to begin to be cleared from lungs
Many neonates show some mild respiratory distress immediately after delivery as the clearing of fluid continues.
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how to read a chest x-ray (CXR)
RIP ABCDE
R: rotation (check clavicles)
I: inspiration (9 ribs)
P: penetration (correct amount of x-ray material; should see b/t vertebrae)
A: should see two bronchi splitting from airway
B: fractures of anomalies
C: rt and lt heart borders
D: diaphragm borders should be well-defined
E: everything else (lines, leads, foreign bodies)
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CXR - newborns highlights
Heart: no more than 65% of width of chest
Diaphragm: should see sharp costophrenic angles b/t lung, chest floor, and diaphragm; if not, think pulmonary effusion)
Pulmonary vasculature: fills medial 1/3; if more, think possible heart failure
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RFLLS
retained fetal lung liquid syndrome; resolution of symptoms in 1-5 days
- CXR: "wet silhouette"
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meconium aspiration syndrome (MAS)
NOT COMMON in premature babies
Meconium is present in amniotic fluid in 12% of deliveries
- of that 12%, 4-6% are complicated by aspiration
- of that 4-6%, 50% require mechanical ventilation
Usually occurs in term or near term infant
Passage of meconium RARE before 34 wks
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3 serious outcomes of MAS
meconium aspiration syndrome
1. persistent pulmonary hypertension of newborn - tar-like stuck in lungs
2. pneumothorax
3. pneumonia (inflammatory rather than infection)
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Hyaline Membrane Disease/Respiratory Distress Syndrome (RDS)
Occurs almost exclusively in premature infants (
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Most common cause of growth retardation in developed countries v. developing countries
hyperthyroidism (Graves disease) vs. malnutrition
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Risk to baby of having a mother over 35 v. a mom under 16
old: Down Syndrome
young: pregnancy induced hypertension and prematurity
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what is the most sensitive indicatory of lower airway disease?
respiratory rate / tachypnea
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nuchal cord
umbilical cord around neck of baby; can get tighter as baby comes down; compressing cord which can compress vein and cut off O2 supply to baby.
Cord: 2 arteries and 1 vein; oxygen is in vein (veins do not have muscular walls)
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growth hormones - fetal - post-publital
fetal: insulin most powerful growth hormone
pre-pubital: growth hormone
post-pubital: estrogen and testosterone
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erb's palsy
injury to newborn as a result of birth; stretch injury to brachial plexus causing paralysis of muscled, inward turn, and hand faced palm up in back
- will recover quickly
