Mod IV: Pediatric Hematologic - Renal - Endocrine - Hepatobiliary - GI - Thermoregulation - Central Nervous System Flashcards
Hematologic System
What’s normal Hemoglobin in a healthy newborn?
19g/dl
Hematologic System
What’s normal Hemoglobin in premature infant?
13-15g/dl
Hematologic System
What percentage of Hemoglobin in newborn and infant is fetal hemoglobin (HgbF)?
70-80%
Hematologic System
Why is Neonatal oxyhemoglobin curve shifted to the left?
To increase hemoglobin affinity for O2
Hematologic System
Neonatal oxyhemoglobin curve shifted to the left. This increases hemoglobin affinity for O2. What are advantages of this?
Increase ability to uptake O2 from the mother a the placental interface
Hematologic System
Neonatal oxyhemoglobin curve is shifted to the left. This increases hemoglobin affinity for O2. What are disadvantages of this?
Decreases the release of O2 to the tissues,
which makes them prone to hypoxemia
Hematologic System
The neonatal oxyhemoglobin curve is shifted to the left. This increases hemoglobin affinity for O2. A disadvantage of this is a decrease in the release of O2 to the tissues, which makes them prone to hypoxemia. What is this compensated by?
Increase in CO
Higher Hgb levels
Increase in blood volume per kg, as compared to an adult
Hematologic System
What is the P50 of HgbF?
18-20
<em>(What’s P50?)!!!!</em>
Hematologic System
What’s P50 of hemoglobin? What’s normal P50?
The P50 of hgb is the oxygen tension at which hemoglobin is 50% saturated
The normal P50 is 26.7 mm Hg
Hematologic System
What’s the mormal P50 for adult Hgb?
27 mmHg
Hematologic System
When does the fetal hemoglobin phenomenom disappear?
In first few weeks
with physiologic anemia occurring at 2-3 months
Hematologic System
When does Physiologic anemia occur?
Physiologic anemia occurring at 2-3 months
Hematologic System
How does Physiologic anemia (@ 2-3 mo) manifest?
Hgb falls to normal levels of 10-11 g/dl
Hgb remains at physiologic anemia levels until early teens
Oxygen-Hemoglobin Equilibrium
Newborn have a high concentration of HgbF (70-80%). How does newborn Hgb affinity to O2 compare to adult Hgb affinity to O2?
New born Hgb affinity to O2 (P50 of 18-20) is higher than adult Hgb affinity to O2 (P50 of 27)
Oxygen-Hemoglobin Equilibrium
How does higher Hgb affinity to O2 affect the Oxygen-Hemoglobin dissociation curve?
Shifts the Oxygen-Hemoglobin dissociation curve to the left
Oxygen-Hemoglobin Equilibrium
At what age is HgbF replaced by adult Hgb?
During the first 3 months of life, and
the P50 then equals that of adults
Oxygen-Hemoglobin Equilibrium
At what age does the P50 reaches its peak? What’s peak values of P50? How long does P50 remains at peak?
By 9 months of age,
the P50 reaches its peak of 29-30mmHg
where it remains until puberty
Oxygen-Hemoglobin Equilibrium
During which developmental period is O2 delivery enhanced?
During the busiest growth period of the pediatric pt’s life
Renal Function
T/F: The concentrating capacity of an infant’s kidney is less than that of an adult
True
Renal Function
In response to water depravation, what can the kidneys of a term infant do?
Increase the osmolarity of urine to a maximum of
600-700 mOsm/kg
Renal Function
In response to water depravation, the kidneys of a term infant can increase the osmolarity of urine to a maximum of
600-700 mOsm/kg
Renal Function
In response to water depravation, the kidneys of a term infant can increase the osmolarity of urine to a maximum of 600-700 mOsm/kg. In contrast, maximum urine osmolality in adults is:
1200 mOsm/kg
Renal Function
Variations in the release of which hormone regulates the osmolality of the extracellular fluid?
Variations in the release of AntiDiuretic Hormone (ADH) regulates the osmolality of the extracellular fluid
Renal Function
T/F: Although dehydrated newborns cannot concentrate urine as efficicently as adults can, free water clearance is greater in infants than adults
True
Renal Function
After a free water load, infants can excrete a markedly diluted urine of up to
50 mOsm/kg
Renal Function
After a free water load, infants can excrete a markedly diluted urine of up to 50 mOsm/kg. In contrast the maximally diluted urine an adult can produce is:
70-100 mOsm/kg
This leads to impaired ability to handle a water load and clear drugs
Renal Function
Overall, how is GFR?
Overall, there is a ↓ GFR
GFR is 15-30% of normal adult value
Renal Function
By 1 month, how is GFR changed? At what age is the adult GFR reached?
GFR becomes 70% of mature GFR by 1mos
And the Adult GFR value is reached by 1yr
Renal Function
Why is there ineffective concentrating ability until 6-12 mos
Limited renal tubular function
Resulting in ineffective concentrating ability until 6-12 mos
Renal Function
What’s the cause of the Limited renal tubular function that results in ineffective concentrating ability until 6-12 mos?
Hypotonicity of the adrenal medulla
Renal Function
Why do they have normal “acidosis”?
Decreased reabsorptive function
Loss HCO3 = which leads them to having a normal “acidosis”
Renal Function
Why are they prone to hyponatremia/hypovolemia?
Decreased reabsorptive function
Makes them Obligated Na+ losers = which makes them prone to hyponatremia/hypovolemia
This is why IVF should contain Na+
Renal Function
What’s the Net renal function effect?
Impaired ability to handle (hold on to) a saline & water load
(They will not reabsorb it! or they will just loose it!!!)
This affects the Renal clearance of drugs
This also affects how drug metabolites are diminished
Endocrine System
With the endocrine system, what do we monitor?
Hypoglycemia
Endocrine System
How is Hypoglycemia defined for older children?
BG < 40 mg/dl
Endocrine System
How is Hypoglycemia defined for neonates?
BG < 30 mg/dl
Endocrine System
Why are Premature infants at greatest risk for Hypoglycemia?
Small for gestational age
Infants of diabetic mothers
Endocrine System
Why are Infants of diabetic mothers at greatest risk for Hypoglycemia?
B/c they have been Exposed to ↑ levels maternal glucose throughout the pregnacy
With that, they have an automatic response which is to ↑ their levels of insulin
Endocrine System
T/F: Hypocalcemia is common in premature neonates and small for gestational age infants
True
Endocrine System
Hypocalcemia is common in premature neonates and small for gestational age infants. What are the causes of this phenomenom?
Decreased stores
Lack of exogenous supply
Parathyroid immaturity
Inadequate vitamin D stores
Asphyxiation
Offspring DM
Transfused with citrated blood
Endocrine System
Why are infants predisposed to hypocalcemic hypotension?
Myocardial contractility more dependent on extracellular Ca2+ due to immature myocardial sarcoplasmic reticulum
Hepatobiliary System
Why may drugs metabolized by P-450 system have a prolonged half-lives?
Liver enzyme systems are immature in the infant
Particularly those involved in phase II (conjugation) reactions
Hepatobiliary System
Why do you need to know which drugs you are administering that are highly protein bound?
Infants also have ↓plasma albumin levels at birth
This results in ↓ protein binding of some drugs
You must know the Pharmacologicals effect of ↓ protein binding of some drugs
Gastrointestinal System
Why is there a higher incidence gastric reflux?
Incompetent LES
Prolonged gastric emptying
Uncoordinated swallowing/respiration until 4-5mos
Upper abdominal disorders, which causes vomiting
Lower abdominal disorders, which causes abdominal distention (failure to pass meconium)
Gastrointestinal System
Uncoordinated swallowing/respiration until how old?
4-5mos
Gastrointestinal System
Upper abdominal disorders, which causes
Vomiting
Gastrointestinal System
Lower abdominal disorders, which causes
Abdominal distention
(failure to pass meconium)
Gastrointestinal System
What’s infant Gastric pH immediately after birth?
Alkalotic
Gastrointestinal System
When does infant Gastric pH reaches Normal adult range?
by 2nd day life
Thermoregulation
Infants are Highly susceptible to hypothermia, why?
Large BSA to weight ratio
Thin layers of insulating fat
Increased metabolic rate
Limited stores of brown fat
Poor central thermoregulation
Thermoregulation
Why can’t infants compensate for cold by shivering?
Central thermoregulation is poor
Thermoregulation
What’s the Principle method of heat production for infants/newborns
Nonshivering thermogenesis or Brown fat metabolism
Thermoregulation
T/F: The metabolism of Brown fat is severely limited in the premature infant and sick neonate
True
Thermoregulation
T/F: (Inaudible) anesthetic inhibits thermogenesis and brown adipocytes
True
Thermoregulation
Where is Brown fat is stored?
Intrascapulary space
Around large vessels
In the neck
Around the sternum
Around the kidneys and the adrenals
Thermoregulation
T/F: Cool temperatures and anesthetic agents can convert newborns/infants to poikilotherm
True…
Thermoregulation
What’s a poikilotherm?
An organism that cannot regulate its body temperature except by behavioral means such as basking or burrowing
Thermoregulation
How we can reduce heat loss in these pts?
By limiting temperature gradient between patient & environment
Thermoregulation
What are the routes of heat loss?
Radiation
Conduction
Evaporation
Thermoregulation
Via which route do infants lose most of their heat?
Radiation
Thermoregulation
How do you reduce heat loss via radiation (route infants lose most of their heat)?
Warm OR to 28-30 C
Double-shelled Isolette for transport
Radiant warmer
Thermoregulation
How do you reduce heat loss via Conduction?
Place infant on warming mattress
Thermoregulation
How do you reduce heat loss via Evaporation?
Humidified gases
Warm fluids
Warm-air blankets
Central Nervous System
The Brain represents what proportion of the body weight?
Brain is 1/10th of the body weight
Central Nervous System - Spinal cord development
In the Embryo, the spinal cord occupies:
Entire spinal canal
Central Nervous System - Spinal cord development
At birth where is the lower end of cord?
At L3 level
Central Nervous System - Spinal cord development
By 1 year of age, where is the end of the cord?
At the level of L1 (adult level)
Central Nervous System - Spinal cord development
As vertebral column grows, spinal nerve roots are drawn into spinal canal. Which structure emerges from this?
Cauda equina
Central Nervous System - Spinal cord development
Why is testing primitive reflexes (Moro, grasp, Babinski) a useful tool when assessing neuronal development?
Primitive reflexes (Moro, grasp, Babinski) should disappear as myelination occurs
Central Nervous System - Spinal cord development
When do Primitive reflexes (Moro, grasp, Babinski) disappear? Why?
Primitive reflexes (Moro, grasp, Babinski) disappear as myelination occurs
Myelination is not complete until 3rd year of life
