1. Fetal Circulation and Newborn Transition to Life
Melissah Burnett & Jacqui McGregor
La Trobe University, Melbourne.

2. KEEPING A PDA OPEN
Some cardiac abnormalities are considered “duct-dependent”; these can be cyanotic or acyanotic
Duct-dependent defects can be related to pulmonary flow (for example pulmonary stenosis or pulmonary atresia); or related to systemic flow (for example hyperplastic left heart or transposition of the greater arteries)
If there is a definite or suspected diagnosis of a cardiac abnormality, that is duct dependent, a prostaglandin infusion is the treatment of choice (a synthetic version of the hormone that keeps it open inutero); the use of prostaglandin before further investigations and/or surgery has improved the mortality and morbidity outcomes for these neonates 2

3. Objectives
To have an understanding of the anatomy and physiology of fetal circulation
To identify the 3 fetal shunts
To have an understanding of newborn transition and conversion of fetal to neonatal circulation
Identify impediments to this transition

4. The newborn, must make five major adjustments at birth.
Survival Tasks
The newborn, must make five major adjustments at birth.
1) World of air
2) Circulation
3) Wastes
4) Body temperature
5) Response to infection
The moment the umbilical cord is severed the neonate must take over the processes that are critical to survival
1) Removed from the aquatic environment of the uterus, it must adjust to the world of air. The first breath begins even before the umbilical cord is cut.
2) The circulatory relationship between mother and child ceases when the umbilical cord is severed so the neonate must now feed and metabolise nutrients.
3) excrete own wastes, and
4) maintain own body temperature.
5) Mount a response to infection
Newborn has to establish
Lung function
Circulatory changes
Thermoregulation
Endocrine function
Nutrition
Gastrointestinal tract function
Waste removal
Kidney function 4 4

5. Adult Heart
Firstly to understand fetal circulation we must have an understanding of our own circulatory system.
In the adult heart, blood flows from the right atrium to the right ventricle then through the pulmonary arteries to the lungs.
In the fetus however, the lungs are nonfunctional and the blood largely bypasses them.
The heart works like a pump and beats about 100,000 times a day.
The heart has two sides, separated by an inner wall called the septum. The right side of the heart pumps blood to the lungs to pick up oxygen. Then, oxygen-rich blood returns from the lungs to the left side of the heart, and the left side pumps it to the body.
The heart has four chambers and four valves, and it is connected to various blood vessels. Veins are the blood vessels that carry blood from the body to the heart, while arteries are the vessels that carry blood away from the heart to the body
Heart Chambers
The heart has four chambers or "rooms"—two on the left side of the heart and two on the right.
The atria (AY-tree-uh) are the two upper chambers that collect blood as it comes into the heart.
The ventricles (VEN-trih-kuls) are the two lower chambers that pump blood out of the heart to the lungs or other parts of the body. 5 5

6. Review pulmonary & systemic circulations and anatomy of the heart.
Basic Heart Anatomy & Physiology
The heart is primarily composed of muscle.  There are 4 chambers, two upper and two lower, separated by one-way valves. 
On the right side the upper chamber, the Right Atrium, receives "used", or de-oxygenated, blood from the body through the Superior Vena Cava (SVC) and Inferior Vena Cava (IVC). The blood partially runs and partially is pushed into the Right Ventricle through the Tricuspid Valve (TV) during diastole, between contractions. Then, when the heart contracts in systole, the Tricuspid Valve, a one-way valve tethered to the floor of the Right Ventricle, closes and the Pulmonic Valve (PV) is pushed open. The blood is pumped through the Pulmonic Valve and into the Pulmonary Artery, toward the lungs, to be re-oxygenated.
When the blood has been reoxygenated it is returned to the Left Atrium through the Pulmonary Veins, where it flows into the Left Ventricle through the Mitral Valve during diastole. When the heart contracts in systole the Mitral Valve, tethered to the floor of the Left Ventricle, closes, and the blood is pushed through the opened Aortic Valve (a small portion of which is seen just to the left of the Mitral Valve) into the Aorta, then on to the body.  At the end of the contraction the Aortic Valve closes. 6 6

7. Anatomical Structures of Fetal Circulation
Includes:
Placenta
Umbilical Vein (X1)
Ductus Venosus
Foramen Ovale
Ductus Arteriosus
Umbilical Arteries (X2)

8. Placental Transport The main functions of the placenta include:
Gas exchange
Nutrients
Disposal of waste products
Hormones
Other things can cross placenta
maternal antibodies
drugs
infectious agents
The main functions of the placenta include
Manufacturing various pregnancy related hormones (mainly steroid not protein)
Gas exchange (oxygen, carbon dioxide, carbon monoxide)
Provision of nutritients (water, glucose, vitamins, electrolytes)
Disposal of waste products (urea, uric acid, bilirubin)
Other things can cross placenta
maternal antibodies
drugs and their metabolites
infectious agents
cytomegalovirus, rubella, measles, micro-organisms 8 8

9. Placenta
Facilitates gas and nutrient exchange between maternal and fetal blood.
These substances diffuse between maternal and fetal blood through the placental membrane.
The blood itself does not mix.
The placenta is a low resistance component of the fetal circulation.

10. The Placenta 10

11. Umbilical Circulation
An umbilical vein carries oxygenated blood and nutrients from the placenta to the fetus.
A pair of umbilical arteries carry deoxygenated blood & wastes from the fetus to placenta.
1umbilical vein: brings oxygenated blood and nutrients to the fetus
2 umbilical arteries: return non-oxygenated blood, metabolic waste, CO2 to placenta

12. Umbilical Vein Transports O2 rich blood & nutrients
Enters ductus venosus
80% saturated with O2
the umbilical vein transports blood rich in O2 and nutrients from the placenta to the fetal body.
The umbilical vein enters the body through the umbilical ring and travels along the anterior abdominal wall to the liver.
About 1/2 the blood it carries passes into the liver.
The other 1/2 of the blood enters a vessel called the ductus venosus which bypasses the liver.
The umbilical vein is the only fetal vessel that carries this enriched blood. The remaining vessels of the fetus carry a mixture of enriched and depleted blood.
 Blood returning to the fetus via the umbilical vein is 80% saturated with oxygen. Traveling from the placenta to the organs of the fetus, the highly oxygenated blood in the umbilical vein slowly loses its oxygen concentration by mixing with desaturated blood in several places:
1)  in the liver by mixing with a small amount of blood from the portal system,
2) in the  inferior vena cava which carries deoxygenated blood returning from the lower extremities, pelvis and kidneys,
3) in the  right atrium by mixing with returning blood from the head and extremities,
4) at the entrance of the  ductus arteriosus into the descending aorta. 12 12

13. Ductus Venosus
Approximately 45% of blood from the umbilical vein enters the portal circulation allowing the liver to process nutrients.
Approximately 55% of the blood passes thru the Ductus Venosus, a shunt which bypasses the liver.
The ductus venosus travels a short distance and joins the Inferior Vena Cava.
The ductus venosus travels a short distance and joins the inferior vena cava.
There, the oxygenated blood from the placenta is mixed with the deoxygenated blood from the lower parts of the body.
This mixture continues through the vena cava to the right atrium. 13 13

14. Umbilical Vein Blood continues to travel up the Inferior Vena Cava
Empties into the Right Atrium of the heart
A large portion of the blood is shunted into the Left Atrium through the Foramen Ovale

15. Fetal Circulation Differences
The exchange of gases and nutrients between fetal blood and maternal blood occurs in the placenta. * * Thus the blood leaving the placenta is rich in O2 and nutrients. This blood flows through a single umbilical vein * * which carries the blood from the placenta through the umbilical cord to the liver of the fetus. Since the umbilical vein is carrying blood rich in O2 , it is indicated with a dark red in the diagram. From the liver, most of the blood bypasses the liver through the ductus veinosus * * which introduces the blood into the inferior vena cava and from there into the right atrium. Notice that the dark red blood in the ductus veinosus mixes with blue (low O 2 ) blood returning from the lower regions of the body. As a result of this mixing, the blood in the right atrium is not as highly oxygenated and is thus represented as pink. This is the blood that is pumped through the systemic circulation to the body of the fetus. Some of this blood returns to the placenta through right and left umbilical arteries * * which branch off of the internal iliac arteries and pass through the umbilical cord to the placenta, thus completing the cycle. * 15 15

16. Placenta Umbilical Vein Liver Ductus Venosus Inferior Vena Cava
* Blood flows from the placenta, * * through the single umbilical vein * * * which passes through the umbilical cord to the liver. * * From the liver * * the blood travels through the ductus venosus * * * which introduces blood into the inferior vena cava. * * Blood from the inferior vena cava * flows into the right atrium * where it started. *
Right Atrium 16 16

17. Foramen Ovale
Blood is shunted directly into the left atrium through an opening called the foramen ovale.
R ►L shunt
There is a valve with two flaps that prevents back-flow.
Foramen Ovale
As the blood from the inferior vena cava enters the right atrium, a large proportion of it is shunted directly into the left atrium through an opening called the foramen ovale.
A small valve, septum primum is located on the left side of the atrial septum overlies the foramen ovale and helps prevent blood from moving in the reverse direction.
The rest of the fetal blood entering the right atrium, including a large proportion of the deoxygenated blood entering from the superior vena cava passes into the right ventricle and out through the pulmonary trunk.
fetal blood vessel connecting the umbilical vein to the IVC … blood flow regulated via sphincter … carries mostly hi oxygenated blood 17 17

18. Blood Flow thru Heart
Blood continues the journey to the Left Ventricle blood is then pumped into the Aorta
Blood is circulated to the upper extremities.
Blood then returns to the Right Atrium via the Superior Vena Cava

19. Right Atrium Foramen Ovale Left Atrium Left Ventricle Aorta
Instead of passing through the tricuspid valve, some blood could leave the right atrium * * *through the foramen ovale * * * to enter the left atrium. * * From the left atrium * the blood then would travel through the mitral valve * * * into the left ventricle. * * The blood would travel from the left ventricle * through the aortic semilunar valve * * * into the aorta. * * *
Aorta 19 19

20. Blood flow thru Heart
The remaining of the fetal blood in the Right Atrium, including a large proportion of the deoxygenated blood returning from the Superior Vena Cava passes into the Right Ventricle and out through the Pulmonary Trunk.
The blood continues along the Pulmonary Artery the majority is shunted away from the lungs thru the Ductus Arterious into the Aorta Arch a small amount goes to the maturing lungs.

21. Fetal Circulation Routes - through the Heart
Right Atrium
Right Ventricle
Pulmonary Artery
Ductus Arteriosus
Aorta

22. Aorta Common Iliacs Internal Iliacs Umbilical Arteries Placenta
From the aorta * * * the blood would travel into the right and left common iliac arteries. * * From the common iliac arteries * the blood would flow into the internal iliac arteries * * * from which the umbilical arteries arise. * * The two umbilical arteries * carry the blood through the umbilical chord to the placenta * * where oxygenation occurs. * 22 22

23. Pulmonary Vascular Constriction
Pulmonary Resistance
▲Pulmonary Vascular resistance due to partially collapsed alveoli
▼blood flow to lungs
Relative hypoxia
Vasoconstriction
Only a small volume of blood enters the pulmonary circuit, because the lungs are collapsed, and their blood vessels have a high resistance to flow.
Enough blood reaches the lung tissue to sustain them.
Pulmonary Vascular Constriction 23 23

24. Ductus Arteriosus
A vascular connection between the Pulmonary Artery and the Aorta.
It allows blood to bypass non-functioning lungs and return to the placenta via the Descending Aorta and Umbilical Arteries
Returns blood to placenta
The DA is a muscular connection consisting of 3 layers
Most of the blood in the pulmonary trunk bypasses the lungs by entering a fetal vessel called the ductus arteriosus which connects the pulmonary trunk to the descending portion of the aortic arch.
As a result of this connection, the blood with a relatively low O2 concentration which is returning to the heart through the superior vena cava, bypasses the lungs.
At the same time, the blood is prevented from entering the portion of the aorta that provides branches leading to the brain. 24 24

25. Ductus Arteriosus 25

26. Fluids always follow the path of least resistance.
Blood Flow
Fluids always follow the path of least resistance. 26

27. Umbilical Arteries
Returns deoxygenated blood from Descending Aorta to placenta
Re-oxygenated in the placenta
The blood carried by the descending aorta is partially oxygenated and partially deoxygenated.
Some of it is carries into the branches of the aorta that lead to various parts of the lower regions of the body.
The rest passes into the umbilical arteries, which branch from the internal iliac arteries and lead to the placenta.
There the blood is reoxygenated. 27 27

28. Fetal vs. Neonatal Circulation
Low pressure system
Lungs non-functional
Right to left shunting in the heart
High pulmonary resistance
Low systemic resistance
Neonate
High pressure system
Lungs functional
Left to right blood flow in the heart
Low pulmonary resistance
High systemic resistance

29. Intra-Uterine Circulation
High pressure in right atrium and low pressure in left atrium
RL via foramen ovale
Fetal pulmonary vascular resistance high
RL via ductus arteriosus
Fetal systemic vascular resistance low

30. 30

31. Conversion: Fetal to Neonatal Circulation
At birth the first breaths are the catalyst for the transition to neonatal circulation
Lungs inflate with oxygen with an increased atmospheric pressure
Lungs now become a low-pressure system as pulmonary vessels dilate with rise in oxygen level
Alveolar fluid is displaced
Aeration of the lungs at birth is associated with 1. a dramatic fall in pulmonary vascular resistance due to lung expansion. 2. a marked increase in pulmonary blood flow (thus raising the left atrial pressure above that of IVC) 3. a progressive thinning of the walls of the pulmonary arteries (due to stretching as lungs increase in size with first few breaths)
The first breath: … the pulmonary alveoli open up: … pressure in the pulmonary tissues decreases … Blood from the right heart rushes to fill the alveolar capillaries … Pressure in the right side of the heart decreases … Pressure in the left side of the heart increases as more blood is returned from the well-vascularized pulmonary tissue via the pulmonary veins to the left atrium
Resulting circulatory changes include: … blood pressure is now high in the aorta and systemic circulation is well established 31 31

32. 32

33. Transition 33

34. Decreased Pulmonary Resistance
Pulmonary vessels vasodilate
Fall in PVR
Increased PBF 34

35. Closure of the Ductus Arteriousus
Highly oxygenated arterial blood in the Ductus Arteriosus causes it constrict.
Cessation of circulating PGE2 from maternal circulation. And increased metabolism of circulating prostaglandins by the lungs
Bradykinin – released on lung inflation
Within hours the DA constricts and will eventually become the Ligamentum Arteriosus
At the same time, the lungs release bradykinin (vasodilator) and falling prostaglandin levels cause constriction of the smooth muscle in wall of the DA, reducing flow. Bradykinin works by acting on endothelial NO stimulator e NOS to increase NO produced, thus inducing vasodilatation.
The DA constricts at birth, but there is often a small shunt of blood from the aorta to the left pulmonary artery for a few days in a healthy, full-term infant. … In premature infants and in those with persistent hypoxia the DA may remain open for much longer. … Oxygen is the most important factor in controlling closure of the DA in full-term infants. Closure of the DA appears to be mediated by bradykinin, a substance released by the lungs upon initial inflation. … Bradykinin has potent contractile effects on smooth muscle. Action depends upon the high oxygen content of the aortic blood resulting from aeration of the lungs at birth. … When the PO2 of blood passing through the DA reaches about 50 mm Hg, the wall of the DA constricts. (May be mediated direct or may be mediated by Oxygenís effect on decreasing PG E2 and prostacylcin secretion. (unlike in a coarctation of aorta which requires PGE2 infusion to reopen the DA for blood flow. … As a result of reduced pulmonary vascular resistance, the pulmonary arterial pressure falls below the systemic level and the blood flow thru the ductus arteriosis is diminished. 35 35

36. Increased Systemic Pressures
Clamping the cord shuts down the low pressure placental system and increases systemic vascular resistance
Blood is now pumped to the heart and lungs for oxygenation rather than the placenta

37. Closure of the Foramen Ovale
Increased blood flow of oxygenated blood returning from the lungs
Increases the pressure to the left side of the heart forces blood against the Septum Primum causing the Foramen Ovale to close and become Fossa Ovalis
Foramen ovale (see drawing) … Before birth the foramen ovale allows most of the oxygenated blood entering the right atrium from the IVC to pass into the left atrium … Prevents passage of blood in the opposite direction because the septum primum closes against the relatively rigid septum secundum. … Closes at birth due to decreased flow from placenta and IVC to hold open foramen, and … More importantly because of increased pulmonary blood flow and pulmonary venous return to left heart causing the pressure in the left atrium to be higher than in the right atrium. … The increased left atrial pressure then closes the foramen ovale against the septum segundum. … The output from the right ventricle now flows entirely into the pulmonary circulation. 37 37

38. Closure of the Ductus Venosus
Clamping of the umbilical cord increases systemic vascular resistance
Ductus Venosus constricts and becomes the Ligamentum Venosum

39. Function/Structural Closure
Functional closure of the foramen ovale and ductus arteriosus occurs soon after birth
Overall anatomic changes are not complete for weeks 39

40. Extra-uterine Circulation
Lungs inflate  decrease in pulmonary vascular resistance and increase in pulmonary vascular flow
Blood O2 levels rise  further decrease in pulmonary vascular resistance and ductus arterious constricts
Increased pressure in LEFT atrium and decreased pressure in RIGHT atrium  formamen ovale closes
Umbilical cord is clamped  ductus venosus closes  increased systemic vascular resistance
Ductus Arteriosus
The ductus arteriosus is a direct connection between the pulmonary trunk and the dorsal aorta. Postnatal closure occurs initially by by smooth muscle contraction and begins at the first breath and is rapid, completed within the first day (about 15 hr after birth). Anatomical closure is much slower occuring by 2–3 weeks after birth (33% of infants), by 2 months (90% of infants) and by 1 year (99% of infants).
The adult anatomical remnant of the ductus arteriosus is the ligamentum arteriosum.
The ductus venosus connects portal and umbilical blood to the inferior vena cava. Functional closure occurs postnatally within hours. Structural closure commences days after birth and completes by 18 to 20 days.
The adult anatomical remnant of the ductus venosus is the ligamentum venosum (a dorsal fissure on the liver).
Foramen Ovale
There are two separate forms of foramen ovale closure; functional and structural. Functional closure begins at the first breath and is rapid. Structural (anatomical) closure is much slower and generally occurs before the end of the first year. 40 40 40

41. Conversion: Fetal to Infant Circulation
What happens to these special structures after birth?
Umbilical arteries atrophy
Umbilical vein becomes part of the fibrous support ligament for the liver
The foramen ovale, ductus arteriosus, ductus venosus atrophy and become fibrous ligaments 41

42. Conversion: Fetal to Neonatal Circulation
Foramen ovale
Closes shortly after birth, fuses completely in first year.
Ductus arteriousus
Closes soon after birth, becomes ligamentum arteriousum in about 3 months.
Ductus venosus
Ligamentum venosum
Umbilical arteries
Medial umbilical ligaments
Umbilical vein
Ligamentum teres

43. At birth, the lungs assume the function of oxygen and carbon dioxide exchange. The umbilicus * is tied off and cut to stop the flow of blood through the umbilical arteries and the umbilical vein. * The ductus venosus * closes and remains in place as a ligament. With the initiation of respiration, the pulmonary arteries * dilate allowing blood in the pulmonary trunk to flow to the lungs. The ductus arteriosus * constricts and closes to become the ligamentum arteriosum. * The increased flow of highly oxygenated blood through the lungs and into the left atrium causes the foramen ovale * to close, * thus establishing the normal post-birth circulation pattern. The fossa ovalis marks the former location of the foramen ovale in the septum wall between atria. * 43 43

46. Common Defects Patent Ductus Arteriousus Patent Foramen Ovale
Prems, hypoxia, immaturity
Patent Foramen Ovale
patent ductus arteriosus … common in females 2-3 times more than males, unknown reason why … If instead of functional closure after birth there is patent structure then aortic blood is shunted into the pulmonary artery. … Most common congenital anomaly associated with maternal rubella infection during early pregnancy (mode of action by virus unclear) … Premature infants usually have a PDA due to hypoxia and immaturity. … Surgical closure of PDA is achieved by ligation and division of the DA. 2. Patent foramen ovale … most common form of an Atrial Septal Defects (ASDs) … a small isolated patent foramen ovale is of no hemodynamic significance; but if other defects present (e.g. pulmonary stenosis or atresia), blood is shunted through the foramen ovale into the left ventricle, producing cyanosis, a dark bluish coloration of the skin and mucous membranes resulting from deficient oxygenation of the blood. … A probe patent foramen ovale is present in up to 25% of people. A probe can be passed from one atrium to the other through the superior part of the floor of the fossa ovalis. Though not clinically significant (usually small) but may be forced open because of other cardiac defects and contribute to functional pathology of the heart. Results from incomplete adhesion between the original flap of the valve of the foramen ovale and the septum secundum after birth. 46 46

47. Stimuli To Initiate The First Breath
Temperature change
Light stimulation
Noise
Cold
Touch
Physical stimulation /proprioception
Respiratory and metabolic acidosis
Negative pressure in the chest cavity resulting from the recoil of the chest after exiting the vaginal canal

48. Normal Transition
These major changes take place within seconds of birth:
Fluid in the alveoli is absorbed and replaced by air
Umbilical arteries and veins constrict with clamping
Blood vessels in lung tissue relax increasing pulmonary blood flow
Increase in systemic blood pressure and decrease in pulmonary pressure 48

49. First breath
PVR SVR 49

51. When things go wrong in the Transition
Group Work

52. Failure to take first breath and/or sustain adequate breathing
What may contribute to abnormal transition and what will be the outcome in relation closure of fetal shunts
Failure to take first breath and/or sustain adequate breathing

53. Excessive blood loss or poor cardiac contractility
What may contribute to abnormal transition and what will be the outcome in relation closure of fetal shunts
Excessive blood loss or poor cardiac contractility

54. Sustained constriction of pulmonary arterioles
What may contribute to abnormal transition and what will be the outcome in relation closure of fetal shunts
Sustained constriction of pulmonary arterioles

55. What may contribute to abnormal transition and what will be the outcome in relation closure of fetal shunts
Stress

56. What may contribute to abnormal transition and what will be the outcome in relation closure of fetal shunts
Prematurity

57. Inter-uterine distress
What may contribute to abnormal transition and what will be the outcome in relation closure of fetal shunts
Inter-uterine distress

58. Congenital cardiac abnormalities
What may contribute to abnormal transition and what will be the outcome in relation closure of fetal shunts
Congenital cardiac abnormalities

59. Pulmonary abnormalities
What may contribute to abnormal transition and what will be the outcome in relation closure of fetal shunts
Pulmonary abnormalities

61. Failure to initiate and sustain breathing at birth
Birth Asphyxia
Failure to initiate and sustain breathing at birth
Cascading events
Hypoxaemia  hypoxia  damage
Magnitude:
3% of 120 million newborns each year in developing countries develop birth asphyxia and require resuscitation
An estimated 900,000 of these newborns die as a result of asphyxia 61 61

62. Abnormal Transition CONSTRICT
In response to interruption in normal transition
lungs fail to relax
arterioles in bowel, kidneys, muscles and skin
CONSTRICT

63. Abnormal Transition PRESERVED DETERIORATE
Blood flow is redirected to the heart, brain and adrenals
PRESERVED
If oxygen deprivation continues:
Myocardial function and cardiac output fall
DETERIORATE

64. DEATH Abnormal Transition Blood flow to all organs is reduced
lack of adequate organ perfusion
& tissue oxygenation
brain damage
& multisystem organ damage
DEATH

65. Impediments To The Transition.
The Five H’s
Hypothermia
Hypoxia
Hypoglycaemia
Hypotension
Hypercarbia
Situations that impede the decrease in pulmonary vascular resistance, or cause acidosis and hypoxemia may result in persistent right-to-left shunting of blood through the ductus arteriosus and foramen ovale (PPHN 65 65

66. Impediments To The Transition.
Inter-uterine distress
Congenital cardiac abnormalities
Pulmonary abnormalities
Inter-uterine distress
Abnormal presentations, maternal haemorrhage/seizures, ascending infection, cord prolapse
Congenital cardiac abnormalities
Hypoplastic left heart syndrome, coarctation of the aorta, transposition of the great vessels, tetralogy of fallot
Pulmonary abnormalities
Hypoplastic lungs, congenital pneumonia, decreased surfactant production (prematurity/IDM) 66

67. What Can Go Wrong During Transition?
Insufficient ventilation and/or airway blockage
Excessive blood loss or poor cardiac contractility
Sustained constriction of pulmonary arterioles

68. Clinical Manifestations Associated with Asphyxia
Factors Influencing Organ Injury
Duration of the insult
Adaptive mechanisms of the fetus
Cause of the asphyxial process
e.g.abruption versus infection
Associated event/s- e.g.meconium

69. Clinical Manifestations Associated with Asphyxia
CNS- may range from hyper alert to moderate and/or severe encephalopathy  seizures
Renal - oliguria (UO < 1 cc/kg/hr) or anuria
Fluid retention- maybe secondary to urine output, SIADH, rhabdomyolysis
Cardiac dysfunction- right or left sided ventricular dysfunction alone/combined  hypo/hypertension

70. Clinical Manifestations Associated with Asphyxia
Pulmonary - PPHN, haemorrhage
Gastro-intestinal- ileus, bloody stools, NEC
Hepatic- transaminase elevation, cholestatic jaundice
Metabolic/endocrine-hypoglycaemia, hypocalcaemia hypomagnesaemia,
Hematological-bleeding

71. References www.echocharity.org.uk
American Academy of Pediatrics
Textbook of Neonatal Resuscitation 4th Ed (2000)
NRP Slide Presentation Kit
Askin,D.F. (2001) Complications in the Transition from Fetal to Neonatal Life JOGNN Vol33(3)
Blackburn,S. (2006) Placental Fetal and Transitional Circulation Revisited. Perinatal Neonatal Nursing Vol20 (4)
Witt C. (1997) Cardiac Embryology. Neonatal Network Vol16(1) 43-49
Merenstein, G.B & Gardner, S.L, (2002), Handbook of Neonatal Intensive Care , th Ed, Mosby, St. Louis.

72. Good Websites 72