1. Physiological Response of Newborn to Birth
Chapter 23

2. Neonatal Transition Surfactant production
Breathing initiated by mechanical, sensory, chemical, thermal changes.
Mechanical- pressure from chest compression, recoil
Remaining fluid pulled into interstitial fluid
Problems r/t inadequate chest compression

3. Chemical Stimuli Fetal acidosis, decrease in PO2,increase PCO2
Cord clamped, stress of labor
Stimulation of medulla

4. Thermal and Sensory Shock of cold environment Nerve ending stimulated
Cold stress
Tactile, auditory and visual stimulation
Encourage skin to skin contact

5. Cardiopulmonary Adaptation
Blood flow to lungs established
Oxygen saturation
Newborn anatomy restricts lung expansion
Periodic breathing
Obligate nose breathers

6. Cardiopulmonary Adaptation
Clamping of cord, “shut off the hose”, increase in blood pressure
Perfusion increased by pulmonary blood flow and dilation pulmonary vessels.
Decrease in vascular resistance
Pressure change closes foramen ovale
Ductus arteriosis closes due to PO2
Ductus venosis closure leads to liver profuse

7. Cardiac Fx Normal rate BP Most murmurs transient and benign
Right ventricle versus left ventricle
Pressure gradient changes from left to right

8. Hemodynamics RBC shorter life span Rise in HCT Stress response
Cord clamping
Gestational age
Presence of hemorrhage
Site of blood sample

9. Temperature Metabolism and O2 consumption increase with heat loss
Thin skin, decreased fat
Blood vessels close to surface
Flexed posture
Premature infants

10. Heat Loss Large body surface – Vessels close to skin
Convection- cool air currents, door open
Radiation- heat transfers to cooler surface, place cool object on warmer
Evaporation-water converted to vapor, wet baby
Conduction- loss of heat due to direct contact with object

11. Thermogenesis Increase in BMR, and activity generate heat
Nonshivering thermogenesis (NST)
Infant uses stores of brown fat
Brown fat metabolized quickly to produce heat
Do not chill newborns
Cold stress can delay drug metabolism

12. Hepatic Adaptation Iron stored in fetal liver, last for 6 months
Energy crunch caused by labor and loss of maternal glucose
Newborn converts from use of carbohydrate metabolism to fat metabolism

13. Conjugation of Bilirubin
Bilirubin is byproduct of breakdown of RBCs
In utero bilirubun excreted by placenta
Bilirubin needs to be conjugated to be excreted.
Enzymes in liver conjugate bilirubin- bacteria transforms into urobilirubin
Low levels of glucuronyl transferase and immature liver function

14. Physiologic Jaundice Normal response 2-3 days after birth
Caused by increase volume and RBC destruction
Bilirubin not flushed from plasma
Bilirubin not conjugated
Decreased bacterial flora and motility

15. Nursing Room environment-avoid pink
Head to toe, blanch and assess for yellow
Maintain temp
Monitor for excretion
Feed early
Phototherapy for newborns over 13mg/dl

16. Breastfeeding Jaundice
Peaks in 2-3 weeks
Composition of breast milk may interfere with conjugation
If above 20mg.dl may be asked to cease
Continue to pump
Reassure moms

17. Coagulation Some coagulation factors are Vit. K dependent
At birth bacteria in colon not present for Vit. K synthesis
Dilantin and Coumadin associated with bleeding issues

18. GI Lactose(carb.),proteins easily digested
Starches not easily digested
Lack of pancreatic enzyme limits fat digest.
Some regurge nl, burp do not overfeed
Need 120 cal/kg/day, 5%-10% weight loss.
Meconium- debris, dark, tarry
Differentiate breast feed from bottle fed

19. Kidney Fx Inability to concentrate urine
Decrease in GFR, unable to diurese quickly
Most void within 24 hrs., 6/day
Increase 5-25/day after 2 days
Blood in female diaper due to pseudomenstruation

20. Immunity
Immunoglobin IgG transferred to fetus, passive acquired immunity
Length of immunity to bacteria and virus vary
Lack of IgM, fetus susceptible to gram -
IgA protects, gi, int, eyes, high concentration in colostrum

21. Neurological Fx Able to habituate
Able to fixate on faces or objects with contrast
Blinking reflex
Growth is cephalocaudal
Reflexes present
Defensive motor ability