Physiological changes newborn

Question 1

How long does it take to transition from UI life to EU life?

Answer 1

6-12 hours

Question 2

In fetus circulation, deoxgenated blood comes from (1)…. and travels to placenta in the (2)….., oxygenated in placenta and leaves via (3)… to join the (4)… towards heart

Answer 2

1- desc. aorta 2- umbilical arteries 3- umbilical vein (02) 4- Inferior VC via ductus venosus

Question 3

In fetal heart, pulmonary vasculature resistance is? So what happens?

Answer 3

High so blood mostly bypasses lungs to go via foramen ovale and ductus arteriosus

Question 4

Respiratory adaptations during/after birth?

Answer 4

Chemical- Umbilical cord cut–> - 02 decreased, CO2 increased, low pH all stimulate chemoreceptors to initiate breathing

Mechanical- squeezing chest expels fluid, crying open alveoli, tactile drying Pulm. resistance lowers as PBF increases, flows through to lungs , PAP decreases and PO2 increases - closure of 3 shunts -foramen ovale 3-6 months after birth (pressure in LA increases) -ductus arteriosus (when 02 blood flows through it- 2-3 weeks after birth)

Question 5

Neonatal resp.rate

Answer 5

40-60 per minute sneezing and congestion normal, periodic breathing normal (not >15s)

Question 6

Asphyxia ( during delivery or labour) causes newborns not to … at birth.

Answer 6

They don’t breathe, if continuous ie. into 1° apnea, then 2° apnea- requires +ve pressure ventilation Most are transient

Question 7

Other causes of newborn not breathing

Answer 7

mother analgesics, anesthetics, retained lung fluid, congenital malformation, birth injuries

Question 8

What is the apgar score, when is it checked? What is Ballard score?

Answer 8

The Apgar score is used to describe a baby’s condition at 1 and 5 min after delivery. It is also measured at 5-min intervals thereafter, if the infant’s condition remains poor. -heart rate, respiration, muscle tone, reflex irritability, colour.

SCORE 8-9 : normal healthy neonate @1 and @5mins

SCORE 4-7: close attention

Low apgar: CP arrest, severe asphyxia,…

Ballard: is a commonly used technique of gestational age assessment. It assigns a score to posture, arm recoil, politeal ange, scarf sign, heel to ear- the sum of all of which is then extrapolated to the gestational age of the fetus.

Question 9

Thermoregulation: if newborn gets cold what happens metabolically?

Answer 9

Metabolism brown fat to release heat, needs more O2 and more glucose to reach high metabolic needs of temp release. -pulm.vasoconstriction because of diverting blood from skin to thermogenesis -hypoxia of tissues other than brown fat and therefore anaerobic resp. causes metabolic acidosis. Increased glucose use causes hypoglycemia

Question 10

Hemoglobin in fetus

Answer 10

High 14-21g/dl because of relative hypoxic environment

Question 11

When does Hb fall, and to what level? If preterm, when and how low does Hb fall?

Answer 11

Fall to 10g/dl at around 8 weeks, bc no need for it, RBC production decrease, short RBC lifespan

Falls to 6.5-9g.dL by 4-8 weeks

Question 12

Type of Hb in newborn vs adult

Answer 12

HBF 75%/ HBA 25% during most of gestation, then gradually replaced by age 1 HBA 97% and HBA2 2%

Question 13

Stores of iron,FA,B12 and platelet count in newborn

Answer 13

Normal (adult value)

Question 14

WBC newborn

Answer 14

Higher than adults (10–25 × 10^9/L). (Adult 4-11 x10^9/L)

Question 15

Breastfeeding essential when?

Answer 15

up to 6months, 8-12 times a day, whenever baby shows signs of hunger

Question 16

GI tract as a fetus to newborn changes

Answer 16

Sterile–>normal flora from ingested materials

Question 17

Meconium what is it?

Answer 17

Stool consisting of cells from vernix (cheese liek covering of baby protection in womb),bile, skin cells - passed in first 12-24h. Should be thick, sticky, green/black.

Question 18

Liver: glycemia in newborn

Answer 18

Normal to be hypoglycemic for first day of life, monitored closely.

Question 19

Liver: jaundice physiological in newborn why does it happen?

Answer 19

-RBC destruction -Hb values decreasing drastically -less good conjugation system first few days of life

2nd day of life, 1st is pathological

Question 20

Best way to determine type of jaundice is? in detail… which causes when? say something about each one?

TT when and what?

Answer 20

Age of onset:

• <24 hours - hemolytic:

1. RhD hemolytic disease: usually diagnosed antenatally: jaundice, hepatomegaly, anemia
2. ABO - now more common, some O mothers have IgG anti-A hemolysin which cross placenta and attack RBC
3. G6PD- deficiency of enzyme within RBC causes RBC to lyse
4. Spehrocytosis- rare- usually family history- RBC spehere like and so are lysed: jaundice, anemia and spenmegaly (spleen clears up)

• infection congenital: CMV,

24h- 2weeks: - Physiological, breast milk, infectious UTI, hemolysis, PCV, criger najar (explained other card)

>2weeks: - unconjugated: Physiological, breast milk,….

-conjugated: cholestasis, neonatal hepatitis (in gastro cards)

TT if - plot on graph for correcetd gestational age (bc premies more susceptible), and decide based on levels and type.

• treat underlying disorder
• for unconjugated TT is:
• phototherapy WHEN LEVELS 16 and 18 mg/dL (less for premies) converts unconjugated bilirubin to water soluble pigment excreted in urine. complications: body temp, rash,…
• if dangerous levels >20mg/dL: exchange transfusion: Blood is removed from the baby in small aliquots, (usually from an arterial line or the umbilical vein) and replaced with donor blood (via peripheral or umbilical vein). Twice the infant’s blood volume (2 x 80 ml/kg) is exchanged. Donor blood should be as fresh as possibleand screened to exclude CMV, hepatitis B and C andHIV infection. complications: reacting site, infection, NEC

Question 21

Jaundice <24h dangers and causes?

Answer 21

Means hemolytic disease which means high levels of unconjugated which can travel to brain and cause kernicterus: toxic encephalopathy

-Rh or ABO incompatibility -spehrocytosis -G6PD def -Infection

Question 22

Jaundice >24h causes?

Answer 22

Physiological, breast milk jaundice

Hemolytic disease

UTI

Crigler–Najjar syndrome (rare), in which the enzyme glucuronyl transferase is deficient or absent, may result in extremely high levels of unconjugated bilirubin.

Gilbert- mutation same enzyme as CN- milder.

Question 23

Jaundice > 2 weeks (persistent) causes?

Answer 23

Unconjugated: Physiological or breast milk (most common) Infection (particularly urinary tract) Haemolytic anaemia, e.g. G6PD deficiency

Conjugated (>25 μmol/L): Bile duct obstruction, Neonatal hepatitis

Question 24

If prolonged hyperbilirubinemia is conjugated- what are we worried about and what symptoms?

Answer 24

(>25 μmol/L) is suggested by the baby passing dark urine and unpigmented pale stools. Hepatomegaly and poor weight gain are other clinical signs that may be present.

-neonatal hepatitis syndrome and biliary atresia

Question 25

If prolonged hyperbilirubinemia is unconjugated- what is most common causes and other two causes could be?

Answer 25

• ‘Breast milk jaundice’ is the most common cause, jaundice gradually fades and disappears by 4–5 weeks of age.
• Infection, particularly of the urinary tract
• Congenital hypothyroidism may cause prolonged jaundice before the clinical features of coarse facies, dry skin, hypotonia and constipation become evident- screening (Guthrie test).

Question 26

Renal adaptation at birth?

Answer 26

Replaces placenta as fluid and waste exchange

Rapid increase in renal BF

Immature at birth, concentrating ability low

Question 27

Immunological adaptations at birth?

Answer 27

IgG from mother in 3rd trimester

At birth: colostrum gives IgA

Question 28

What medications do we give at birth? What scoring do we do?

Answer 28

Silver nitrate administration or 0.5% Erythromycin eye ointment - prevent gonococcal opthamia, erythromycin also protects against clamydia

Vitamin K 1 mg i.m. for term babies Vitamin K 0,5 mg i.m. for preterm babies

Ballard and APGAR SCORE

Question 29

Kernicterus

Answer 29

• Lipid-soluble, unconjugated, indirect bilirubin fraction is toxic to the developing central nervous system, especially when indirect bilirubin concentrations are high and exceed the binding capacity of albumin
• deposit in CNS
• usually not below 20mg/dL but can be lower in sick babies |(meningitis,…)
• lethargy, hypotonia,irritability, poor moro reflex, later can develop into seizures, fever, bulging fontanelle
• if survive- can have mental retardation, nerve deafness,…

Question 30

Physiologyical changes HEME

Answer 30

• high Hb (>17 g/dL) and reticulocyte count at birth is caused by a hypoxic environment in utero
• after birth, levels start to fall due to shorter fetal RBC lifespan, decreased RBC production (10g/dL) by 6-8w

(during first 6-8 wk of life, there is virtually no erythropoiesis due to new O2 rich environment),

and increasing blood volume secondary to growth

• lowest levels about 10 g/dL at 8-12 wk age

THIS IS PHYSIOLOGICAL ANEMIA, NO NEED TO TT

Question 31

Difference premie and term

Answer 31

• RBC lifespan shorter
• Hb drops lower @ 8 w
• Cr levels higher (adult levels) vs 0.4 in term
• low GFR (as low as 11) vs 17 in term