Hematology Flashcards
(47 cards)
Hematopoiesis
formation, production, and maintenence of blood cells
begins in the yolk sac at 2 weeks GA
liver becomes main source by 6 weeks until 16 weeks
at 24 weeks - bone marrow main source
Expected physiologic anemia
In utero, low fetal PaO2 stimulates EPO production → resulting in erythropoiesis.
After birth → relative hyperoxic environment results in suppression of EPO from 2 DOL to 6-8 weeks = expected decline in hemoglobin levels over the first 2-3 months of life with a nadir at 6-12 weeks of life.
The decline in hemoglobin (and oxygen carrying capacity) is offset by the gradual right shift in the oxy-hemoglobin dissociation curve which increases oxygen availability to tissues
resolves by 4-6 months of life
Dose of iron supplementation
1 mg/kg/day to 10 mg/kg/day
Heme is converted to ____________ by ____________.
heme → biliverdin by heme oxygenase
Biliverdin is converted to ___________ by ___________
bilirubin by biliverdin reductase
DIC Laboratory Indicators
- thrombocytopenia
- Elevated Fibrin Degradation Products (FDP)
- Elevated D-Dimers
- Prolonged PT
- Prolonged PTT
DIC management
treatment of underlying cause
platelet transfusions, FFP, or cryo
DIC patho
activation of blood clotting proteins is initiated by tissue factor from bacterial products (endotoxins)
→ leads to hypercoagulable state
→ thromboses form (especially in the small vessels of the liver, kidneys, spleen, brain, adrenal glands
→ bone marrow releases platelets
system regulating coagulation is immature and is quickly overwhelmed
results in a deficiency of platelets and clotting proteins
Management of asymptomatic and symptomatic polycythemia
asymptomatic infants with HCT >60-70% can be managed with increased fluid intake
symptomatic infants may require a partial exchange transfusion to dilute circulating blood volume
Normal platelet count in neonate
150k - 450k
Neonatal Alloimmune thrombocytopenia
antibody is produced in the mother against a specific human platelet antigen (HPA) present in the fetus but absent in the mother
tx: random platelets; test infant for HPA, in absence of HPA, maternal platelets indicated
neonatal autoimmune platelets
should be considered in any early onset thombocytopenia with maternal hx of ITP or autoimmune disease;
tx: IVIG + random donor platelets for active bleeding
vitamin K dependent clotting factors
factor II, VII, IX, X
Early Onset Vitamin K Dependent Bleeding Disorder
within 24 hours - usually a result of maternal anticonvulsants or vitamin K antagonists such as warfarin
Classic Vitamin K Deficient bleeding disorder
DOL 2-6 : results because of physiologic deficiency of vitamin k and exclusive breastfeeding or inadequate feeding
Late Onset VKBD
2-12 weeks of age; results in infants who did not receive vitamin K at birth and are receiving inadequate dose (exclusive breastfeeding,ect.) or in infants with hepatobiliary disease
VKBD treatment
transfusions of blood products (PRBCs, FFP) and repeated doses of vitamin K
VKBD lab indicators
elevated PT and PTT, low levels of vitamin K dependent clotting factors
Biliary Atresia
inflammation and fibrosis of the bile ducts;
one of the most common causes of chronic liver disease
BA symptoms
presentation between 2-5 weeks with acholic stools;
cholestatic or prolonged jaundice;
ascites may present later in disease course
conjugated bili >2mg/dL
elevated total serum bili
elevated ALT, ALP, GGT
_________ bilirubin is able to cross the blood-brain barrier
unconjugated
Phototherapy mechanism
converts unconjugated bilirubin to photoisomers (lumirubin) that can be excreted without conjugation
polycythemia risk factors
baby’s risk factors: IUGR, SGA, post-term, delayed cord clamping
maternal risk factors: insulin dependent diabetes, hypertension, smoking, living at high altitude
polycythemia clinical manifestations
CNS: lethargy, irritability, jitteriness
RDS: tachypnea, pulmonary edema, pulmonary hemorrhage, PPHN
Cardiac: tachycardia, cyanosis, CHF, murmur, cardiomegaly
renal: renal vein thrombosis, hematuria, proteinuria
GI: Poor feeding, decreased bowel sounds, abdominal distention
increased risk of hyperbili
