Adaptation to Extrauterine life Flashcards
(59 cards)
1
Q
What affects neonates?
A
- Proper development
- Successful birth
- Successful adaptation
- Passive transfer
- Nutrition
2
Q
What is a neonate age wise?
A
- Newborn within the first 30 days of lief
3
Q
What are three elements that determine disease or not?
A
- Host
- Environment
- Agent
4
Q
When in gestation do organs form?
A
- First months of gestation
5
Q
When in gestation do organs develop?
A
- First half of gestation
6
Q
When in gestation do organs grow and mature?
A
- Last trimester
7
Q
What is the purpose of the fetal membranes fluids?
A
- Transfer oxygen and nutrients
- Eliminate waste
- Protect the fetus
- No immunoglobulin transfer
8
Q
What type of placentation do ruminants have?
A
- Epitheliochorial
9
Q
What types of stress happen during birth?
A
- Physical
- Temperature
- Light
- Sounds
- Oxygen deprivation
10
Q
What are the two hormones that increase during stress/right after parturition?
A
- Epinephrine and cortisol
11
Q
What can happen as a consequence of high epinephrine and cortisol in a sick neonate?
A
- They can mask conditions right after birth
12
Q
When do crashes occur?
A
- Hours after birth often
13
Q
How much time for respiratory system to be functional?
A
- Respiratory
14
Q
How much time needed for immune system to be functional?
A
- Weeks to months
- It’s technically competent but naive
15
Q
What are things that can vary in the neonate that will change how well it adapts to extrauterine life?
A
- Vigor
- Strength
- Stress of birth
- Maternal support
- Environment
16
Q
What critical changes happen in the fetus as it transitions to neonate?
A
- Circulatory changes
- Pulmonary
- Acid-base
- Energy metabolism
- Temperature regulation
- Passive transfer
17
Q
How does circulation change at birth?
A
- Pulmonary resistance increases, which closes the ductus arteriosus (Ductus arteriosus had been shunting blood from the pulmonary artery to the aorta)
- Foramen ovale connects the right and left atrium
- Ductus venosus bypasses the liver to go from portal circulation to the caudal vena cava
18
Q
Describe the process of the lungs opening and closure of the ductus arteriosus in the neonate
A
- Umbilicus separates leading to anoxia
- Reflex gasping leaves the lungs aerated (most lung fluid is absorbed and surfactant keeps the lungs open)
- Decreased pulmonary vascular resistance (ductus arteriosus closes)
- Alveolar ventilation increases
- Ductus arteriosus closes in response to increased oxygen saturation ~5 minutes after birth
19
Q
Describe closure of the foramen ovale in the neonate
- How quickly does it happen?
A
- Increased venous return to LA increases left atrial pressure and reverses the right to left shunt
- This occurs in about 10-20 minutes
20
Q
What does relative prepartum hypoxia do to the ductus arteriosus?
A
- Dilation
21
Q
Ductus venosus closure?
A
- Moot, nothing goes through it
- I guess it’s not that important
22
Q
What happens to chest cavity at birth, and what is the significance?
A
- Chest cavity is compressed
- Lung fluids are partially expelled
- Recoil of chest leads to inspiration of air
- Diaphragm contractions further inflate the lungs
23
Q
What causes initiation of breathing in the neonate?
A
- Loss of the immersion reflex, which inhibits breathing in the womb
- Breathing centers are stimulated (cold, light, touch, and limb movement)
- O2, Co2, and pH receptors are maximally stimulated
24
Q
What can lead to respiratory distress? And what metabolic change will occur secondary to this?
A
- Early separation of placenta
- Prolonged labor
- Compression of umbilicus
- Maternal hyperventilation
- Cesearean section/malpresentation
- drugs (ideally under local)
- Immaturity
ALL of these lead to anaerobic metabolism –> lactic acid
25
How will the fetus present if there is in utero hypoxia?
- +/- hyperactive fetus!
| - YOU NEED TO GET THEM OUT RIGHT AWAY
26
How can we help stimulate breathing in fetuses?
- Remove fetal membranes
- Clear airways fluids (suction)
- Stimulate (massage, move legs, nose, needle in the philtrum)
- Artifical respiration
- Remember lung capacity
- Nasal or endotracheal oxygen
- Keep sternal
27
What should you not do to stimulate breathing in fetuses?
- Spin through the air
- Swing
- Hang on fences
28
What does hypothermia indicate in neonates?
- Inappropriate adaptation
- All neonates lose body heat initially
- Heat production maximum 3 hours after birth
29
Environment factors that can impact thermoregulation
- Temperature
- Moisture
- Wind (the worst)
30
Species differences that can alter thermoregulation
- Body mass/surface area
| - Brown fat (burn through it in 6-12 hours)
31
What is the critical temperature for a calf, and what does that mean?
55°F
- Temperature below which any animal has to increase caloric intake to maintain temperature
32
Other miscellaneous factors that can impact thermoregulation
- maternal behavior and energy/activity
33
How quickly is brown fat used to help with heat production?
1-5 days
34
What is the major form of heat production in neonates?
- Shivering!
- requires energy to continue (liver and other glycogen stores utilized within 4-6 hours)
- Colostrum and milk also
35
What should you check for on PE if you suspect hypothermia?
- Body temp (low)
- Suckle reflex (usually absent)
- Shivering (usually absent)
36
Causes of hypothermia in calves
- Environment (temp, wind, wetness)
- Low energy (hypoglycemia, agroceryosis)
- Disease (metabolic demands can tribute; if shocky they can't absorb nutrition very well)
37
How to treat hypothermia?
- Dry the neonate
- Hot water bath
- Warm air
- Provide warm oral fluids
- Blankets, straw, etc.
38
For how long can the small intestine absorb large sized particles in the neonate?
- For the first 24 hours, the small intestine can absorb large sized particles
39
How long are neonates considered monogastrics?
- 2-4 weeks
40
What happens to metabolic demands in stressed, sick, or debilitated neonates?
- High metabolic demands
| - Must provide adequate (extra) nutrition
41
When are the kidneys functionally mature?
- At birth
42
What is normal urine concentration in the neonate?
- Dilute urine from the milk diet
| - Highly concentrated urine may indicate dehydration (rather than renal failure)
43
When does the nervous system mature?
- Rapidly near and after birth
44
What is the nervous system prone to?
- Trauma and asphyxia
45
What "abnormal" neuro exam findings are actually normal in the neonate?
- Lack menace
| - Hypermetric
46
Skeletal system at birth
- Ossified at birth
47
How long can growth plates take to close?
- Several months to years
48
What can arise from trauma at birth?
- Metabolic and infectious problems
49
Rib trauma sequela
- Tracheal/esophageal problems later
50
Leg trauma sequela
- Unable to get up and nurse
51
When is immune system development complete?
- Mid-gestation
52
Is the immune system functional at birth?
- Yes, it's just naive
Matures with time and exposure to antigens
53
What factors affect a successful birth?
- Health of the dam
- Size of the neonate and the dam
- Presentation and posture (head first, rear first)
- Assistance
54
Clinical findings that suggest dystocia
- Meconium staining
- Difficulty maintaining temperature (waxing and waning)
- Erratic blood glucose
- Nervous system problems
- Hypoxia - neonatal maladjustment AKA dummy
- Facial edema (nursing difficulty)
55
What do you have to worry about with a calf with dystocia?
- Increased risk of disease later in life due to metabolic and organ system derangements
56
When do you see disease conditions that were present during gestation or birth arise?
- First days of life
| - Some are inapparent and hamper extra-uterine adaptation (e.g. sepsis, congenital defects, etc.)
57
Early signs of disease in neonates
- Does not stand and nurse within 2 hours
- disinterest in dam or by the dam
- Lack suckle
- Lacks curiosity
- Lacks vigor
- Often subtle and nonspecific
58
What is the veterinarian's role with neonates?
- Realize that there can be subtle or no physical examination abnormalities
- May need diagnostic tests (CBC/Chem/BG/Blood cultures/FPT/US)
- Survival chances increase if treatments are initiated early and aggressively
- Wait and See approach is NOT ADVISABLE
59
What should we do if the owner suspects problems?
- Listen to them
- Monitor them carefully
- Keep warm and nourished
- Prep owners and provide instructions
- Call sooner rather than later
