Hematology Flashcards
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
Most Common Cause of Late-Onset Thrombocytopenia (>72 hours)
Sepsis
hematopoiesis
the process of pluripotent stem cells delineation into different blood cells
erythropoiesis
the maintenance and production of red blood cells
site of erythropoietin production
after delivery, EPO is produced in the kidneys
Treatment of hemophilia ( unknown factor)
Fresh Frozen Plasma contains all clotting factors (Cryo is missing factor IX)
Lab Indicators of Hemophilia
prolonged aPTT, normal PT, normal platelet count
normal aPTT
30.5-39.5
normal PT value
12.2-14
Hemophilia A (most common) is a deficiency of factor ____
VIII
Maternal Transfer of ____ antibodies provide the newborn with a measure of passive immune protection and are the only ones to cross the placenta in significant amounts (after 20-22 weeks GA)
IgG
Antibodies that evoke primarily _____ or _____ antibody responses are poorly transported across the placenta
IgA or IgM
Early Onset Sepsis commonly occurs _________ and is ________ acquired during __________,
before 72 hours and is acquired horizontally during birth
Most common organisms for Early Onset Sepsis
Group B Streptococcus, E. Coli, Listeria monocytogenes
Late onset Sepsis
occurs after the first week of life (or as early as DOL 3)
Treatment for Early onset sepsis
ampicillin and gentamicin until organism is confirmed
Treatment for late onset sepsis
Vanc and Gent until organism confirmation
ANC (absolute neutrophil count)
predictive of infection if <1000
%WBCs x (% Immature neutrophils + % mature neutrophils) x 0.01
I/T Ratio
%Bands + %Immature Forms
%Mature + %Bands + %Immature Forms
most informative from 1-4 hours after birth
normal <0.2
Immature Neutrophils
bands, myelocytes, metamyelocytes
Neutrophils also known as ….
segs, polys, polymorphonuclear leukocytes (PMNs)
Hydrops
a prenatal form of heart failure almost always caused by fetal anemia; characterized by subcutaneous edema and fluid in 2 compartmental spaces
result of imbalance of interstitial fluid and lymphatic return
2 types: immune and non-immune
Immune Hydrops
maternal antibodies cross the placenta and attack and destroy fetal RBCs; seen in Rh and ABO incompatibility
Nonimmune hydrops
disease or anomalies interfere with fetal fluid management;
- cardiovascular (most common cause)
- dysrhythmias: SVT, atrial flutter, heart block
- cardiac malformation: left and right outflow obstructions
- myocarditis
- chromosomal: aneuploidy, including trisomies 13,18,21, triploidy, and 45, X (turners), achondroplasia
- inborn errors of metabolism
- LONG LIST with conditions under each system
