1. NEONATAL TRANSITION

2. Objectives
Identify physiologic changes during transition to extra-uterine life.
Identify primary features of fetal and newborn pulmonary and circulation.
Identify signs and symptoms of common problems during transition period.
Identify routine care considerations for a newborn during the transition period.

3. Neonatal Transition
Transition is a process of physiologic change in the newborn infant that begins in utero as the infant prepares for transition from intrauterine placental support to extra-uterine self-maintenance.
When the cord is CUT  the newborn must switch rapidly from intrauterine mechanisms to adult physiology.

4. Physiological changes at birth
Time
Breathing
Blood flow
Glucose homeostasis
Temperature control
Renal
GI tract
Seconds Minutes Hours – days Hours - days

5. Events Happening at Birth
First breath
cmH2O vs cmH2O for normal breathing
Removal of fluid from the lungs
Closure of ductus arteriosus
Functional and later anatomic closure
Initialy systemic and pulmonary pressures are equal

6. Pulmonary transition

7. Intrauterine lung condition

8. Pulmonary transition at birth
Fluid filled
Air-filled

9. Pulmonary transition Basic requirements for gas exchange
Ventilation
Fluid clearance
Establishing an air-filled FRC
Spontaneous breathing
Perfusion
Rapid reduction in PVR
Adequate cardiac output with pulmonary perfusion

10. Pulmonary transition Clearance of lung fluid

11. Pulmonary transition The first spontaneous breath

12. Pulmonary transition PVR changes at birth

13. As a result of the gaseous distention and increased oxygen in the alveoli, the blood vessels in the lung tissue relax

14. Pulmonary transition – summary
In case of uncomplicated (physiological) delivery at term pulmonary transition is a spontaneous unasissted event!!

15. Circulatory Adaptation

16. Fetal circulation Fetus From 8 weeks until birth
Organs mature to support external life
Circulation
Umbilical-placental circuit via umbilical cord
Circulatory shunts bypass
Liver
Ductus venosus to inferior vena cava
Lungs
Foramen ovale, between right & left atria
Ductus arteriosus connects pulmonary artery to aorta

18. Circulatory shunts bypass
By pass 1 : DUCTUS VENOSUS
By pass 2 : Foramen ovale

19. Circulatory shunts bypass
By pass 3 : DUCTUS ARTERIOSUS

20. Circulatory Adaptation
FETAL CIRCULATION
High pulmonary resistance
Low resistance in systemic blood flow
RIGHT to LEFT shunt
Foramen Ovale
(Left atrial pressure low because returned lung blood is low and right atrial pressure high due to large volume of blood from placenta)
Ductus arteriosus
(High pulmonary resistance, Low fetal systemic blood and prostaglandin function)

21. Circulatory Adaptation
FETAL
CIRCULATION
NEONATAL
CIRCULATION

22. Circulatory Adaptation
NEONATAL CIRCULATION
Profound changes of circulation at birth
Increased pulmonary blood flow due to the drop of pulmonary resistance  lung expansion.
Venous return from lung increase.
Left atrial press. is raised; Right atrial press. decrease  foramen ovale closed.
Systemic resistance higher than pulmonary resistance (24 hours)  Prostaglandin function  Ductus arteriosus close
Umbilical arteries constrict and placental blood flow stops.

23. Transition to Extra-uterine Life begins when the cord is CUT.
Placenta no longer works as lungs
Lungs begin to exchange gases
First breath inflates lungs and causes circulatory changes
Lungs inflate -  resistance to blood flow through lungs &  blood flow from pulmonary arteries
This results in Newborn Circulation.

24. Barrier in Transitional Period
The baby may not breath sufficiently to force fluid
from the alveoli
The lungs will not be filled with air
Oxygen will not be available for circulating blood through the lungs

25. Failure in increasing systemic blood pressure
Barrier in Transitional Period
Excessive blood loss or hypoxia/ischemia resulting poor cardiac contractility and bradycardia
Failure in increasing systemic blood pressure
Systemic hypotension

26. Barrier in Transitional Period
Low oxygen concentration
Sustained constriction of the pulmonary arterioles
Persistent pulmonary hypertension

27. Consequences of interrupted transition
Tachypnea
Cyanosis
Resp depression (apnea / gasping)
Bradycardia
Hypotension
Low muscle tone

28. The Global Need for neonatal Resuscitation, FIGO, Wall et al

29. Preductal Target O2 Saturations
Breathing/crying?
Good tone?
Yes
Routine Care
Time from Birth
Preductal Target O2 Saturations
1 minutes
60-70%
2 minutes
65-85%
3 minutes
70-90%
4 minutes
75-90%
5 minutes
80-90%
10 minutes
85-90% No
Initial Steps
Observe breathing, HR and tone
Apnea/gasping, and or HR < 100 bpm
Spontaneously breathing
PPV and SpO2 monitoring
Respiratory Distress
Persistent Central Cyanosis
HR < 100 bpm?
CPAP
Consider supplemental O2
Adequate chest explansion?
CPAP Failure, consider intubation
Information:
If HR > 100 bpm and target oxygen saturation is successfully achieved:
Without equipment support  observational care
With equipment support  post-resuscitation care
Yes No
HR < 100 bpm
PPV (O2 100%) + chest compression
Consider intubation
Evaluate head position, airway obstruction, leakage, adequate PIP?
HR < 60 bpm?
Consider drugs and fluid administration

30. Evaluation-Decision-Action cycle

31. Summary
Changes in respiratory and circulation is the key component of transitional period in newborn.
Barrier of transitional period in newborn include delayed removal of lung liquid, failure of systemic blood pressure increase, and failure of lung arterioles dilatation

32. Thank you