HEMA DIS NEWBORN Flashcards
1
Q
is defined as a reduction of the hemoglobin concentration or red blood cell (RBC) volume below
the range of values occurring in healthy persons.
A
Anemia
2
Q
Physiologic Anemia of Infancy
A
- At birth, normal full-term infants have higher hemoglobin (Hb) levels and larger red blood cells (RBCs) than do older children and adults.
- progressive decline in Hb level begins and then persists for 6-8wk.
3
Q
What causes the progressive decline?
A
- Onset of Respiration at birth
- There is also a gradual, normal developmental switch from fetal to adult Hb synthesis after birth
- downregulation of erythropoietin (EPO) production
- Hb concentration continues to decline until tissue oxygen needs become greater than oxygen delivery
> this point is reached between 8 and 12 wk of age, when the Hb concentration is about 11 g/dL
4
Q
The supply of stored reticuloendothelial iron, derived from previously degraded RBCs,remains sufficient for this renewed Hb synthesis, even in the absence of dietary iron intake, until approximately
A
20 wk. of age
5
Q
Blood transfusions (PRBC) in NEWBORN recommended
A
RBC volume of 10-15 mL/kg is recommended
6
Q
Iron supplementation in newborn
A
- at 1mo of age and continuing until about 1 yr.
- Starting dose is 1-2 mg/kg/day of elemental iron.
7
Q
- most widespread and common nutritional disorder in the world
- Most iron in neonates is in circulating hemoglobin
> iron stores are usually sufficient for blood formation in the 1st 6-9 mo of life in term infants
> Delayed (1-3 min) clamping of the umbilical cord can improve iron status and reduce the risk of iron
deficiency
> anemia caused solely by inadequate dietary iron usually occurs at 9-24 mo of age and is relatively
uncommon thereafter.
A
lron-Deficiency Anemia
8
Q
- is the most recognized clinical sign
- not usually visible until the hemoglobin falls to 7-8 g/dL
- readily noted in the palms, nail beds, or conjunctivae
A
Pallor
9
Q
- Happens when the hemoglobin level falls to <5 g/dL
- Ifthe hemoglobin continues to fall
A
- anorexia, and lethargy develop, and systolic flow murmurs
- tachycardia and high output cardiac failure
10
Q
LAB Findings in Iron Def Anemia
- serum ferritin
- transferrin
- MCV
- MCH
- WBC
- Hb
A
- reduced serum ferritin
- Increased serum transferrin
- decrease in mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH)
- White blood cell (WBC) count is normal, but thrombocytosis is often present
- An increase in hemoglobin 21 g/dL after 1 mo of iron therapy is usually the most practical
means to establish the diagnosis.
11
Q
How much dosage is adequate in px with Iron Def Anemia
A
A daily total dose of 3-6 mg/kg of elemental iron in 1 or 2 doses is adequate
12
Q
- is defined as the premature destruction of red blood cells (RBCs)
- Anemia results when the rate of destruction exceeds the capacity of the marrow to produce
additional RBCs - Normal RBC survival time is 110-120 days
A
Hemolytic Anemias
13
Q
Classification of hemolytic anemias:
A
- Intrinsic
- Extrinsic
- Inherited
- Acquired
- Immune
- Nonimmune mediated
14
Q
Daignostic Clues Based in RBC Shape Suggestive of Hemolytic Anemia
- Sickle cells >
- Target Cells >
- Spherocytes >
- “Bite” Cells >
A
- Sickle cells > Sickle Cell Disease
- Target Cells > hemoglobinopathies
- Spherocytes > hereditary spherocytosis
- “Bite” Cells > G6PD deficiency
15
Q
- Common cause of inherited hemolytic anemia
- Described in patients of all ethnic groups
- An intrinsic defect of the erythrocyte membrane and an intact spleen that selectively retains,
damages and removes the erythrocyte - Ankyrin or spectrin > most common molecular defect
- Clinical manifestations
> 75% transmitted as an autosomal dominant trait
> Anemia
> Hyperbilirubinemia - Severity varies:
> Asymptomatic
> Fatigue, pallor and intermittent jaundice
> splenomegaly
A
Hereditary Spherocytosis
16
Q
- refers to a group of genetic disorders of globin-chain production in which there is an imbalance between the a-globin and B-globin chain production
- unbalanced a- and B-globin chain production leading to ineffective erythropoiesis.
- 2 types of Thalassemia:
+ B Thalassemia- result from a decrease in B-globin chains, which results in a relative excess of a-globin chains
+ a Thalassemia - there is an absence or reduction in a-globin production usually due to deletions of a-globin genes.
- result from a decrease in B-globin chains, which results in a relative excess of a-globin chains
A
Thalassemia Syndromes
17
Q
- If not treated, children with homozygous BO-thalassemia usually become symptomatic from progressive anemia, with profound weakness and cardiac decompensation during the 2nd 6 mo of life.
- classic presentation of children with severe disease:
> Maxilla hyperplasia
> Flat nasal bridge
> Frontal bossing
> Pathologic bone fractures
> Marked hepatosplenomegaly - LAB FINDINGS
> Identified on newborn screening (expanded)
> Progressive anemia after the newborn period, often < 6mg/dL
> Hemoglobin electrophoresis > not definitive
> DNA diagnosis of the B thalassemia nutation is recommended - Management
> Transfusion therapy
+ Generally given at intervals of 3-4 weeks
+ Goal to maintain Hb level of 9.5-10 g/dL
+ Monitor for iron overload
A
Homozygous B Thalassemia
(Thalassemia Major, Cooley Anemia)
18
Q
- identified in the newborn period by the increased production of Bart hemoglobin (y4 ) during fetal
life and its presence at birth - occur most frequently in Southeast Asia
- The different phenotypes in a-thalassemia largely result from whether 1 (a+ -thalassemia) or both (
a0 -thalassemia) a-globin genes are deleted in each of the 2 loci.
A
a-Thalassemia Syndromes
19
Q
- Is not identifiable hematologically
- No alterations are noted in the MCV and MCH
A
a-Thalassemia Syndromes
- The deletion of 1 a-globin gene (silent trait)
20
Q
- a-globin alleles can be lost in a trans (-a/-a) or cis (a,a/-SEA) configuration
- cis deletions are most common seen in persons from or descended from Asia or the Mediterranean region
- Manifest as a microcytic anemia than can be mistaken for iron deficiency anemia
A
a-Thalassemia Syndromes
- The deletion of 2 a-globin genes results in a-thalassemia trait
21
Q
- The deletion of 4 a-globin genes causes profound anemia during fetal life
- The deletion of 3 a-globin genes leads to diagnosis of
A
- hydrops fetalis
- HbH disease
22
Q
- X-linked inherited disorder
- DEFECT: glucose 6 phosphate dehydrogenase
> Helps protect RBCs from oxidative stress - triggered by infection, drugs, or ingestion of fava beans
- hemolysis ensues in about 24-48 hr after a patient has ingested a substance with oxidant properties
- Laboratory Findings
> Heinz bodies, precipitated hemoglobin
> A peripheral smear will show “bite” cells
A
Glucose-6-Phosphate Dehydrogenase Deficiency
23
Q
- is defined as a central hemoglobin or hematocrit (Hct) exceeding 2 standard deviations (SD) above
the normal value for gestational and postnatal age. - full-term infant is therefore considered when the hemoglobin concentration is >22 g/dL or Het is >65%.
- Etiologies of neonatal polycythemia are numerous but can be grouped into two broad categories:
> based on passive RBC transfusion into the fetus
> increased intrauterine erythropoiesis
A
Neonatal Polycythemia
24
Q
- result from hyper viscosity (sluggish blood flow causing decreased tissue perfusion)
- irritability, lethargy, tachypnea, respiratory distress, cyanosis, feeding disturbances,
hyperbilirubinemia, hypoglycemia, and thrombocytopenia - Severe complications include:
> seizures, stroke, b
> pulmonary hypertension,
> Necrotizing enterocolitis (NEC),
> renal vein thrombosis, and renal failure
A
Neonatal Polycythemia
25
- is the process of blood clotting in areas of blood vessel injury
- If clotting is impaired, hemorrhage occurs
Hemostasis
26
The main components of the hemostatic process are:
- the vessel wall
- plateletss
- coagulation proteins
- anticoagulant proteins
- and fibrinolytic system.
27
In acquired hemostatic disorders, there are frequently multiple problems with homeostasis that
perturb and dysregulate hemostasis.
- A primary illness (sepsis)
- its secondary effects (shock and acidosis)
- activate coagulation and fibrinolysis and impair the host's ability to restore normal hemostatic
function.
28
- When sepsis triggers
- platelets, procoagulant clotting factors, and anticoagulant proteins are consumed, leaving the
hemostatic system unbalanced and prone to bleeding or clotting
Disseminated Intravascular Coagulation
