Chapter 23: Disorders of the Hematologic System Flashcards
Hypercoagulability
exagerrated hemostasis
thrombocytosis (>1,000,000)
predispose to thrombosis
Arterial Thrombi
associated with turbulent blood flow = atherosclerotic plaque, hyperlipidemia, smoking, DM
treat with antiplatelet aggregates (ASA)
Venous Thrombi
associated with stasis of blood flow = immobility, sickle cell, elevated estrogen, malignancy, obesity
treat with anticoagulants
Primary (Essential) Thrombocytosis
disorder of stem cells
results in dysfunctional platelets
Secondary (Reactive) Thrombocytosis
condition that stimulates thrombopoietin
tissue damage, cancer, chronic inflammatory disorders
Antiphospholipid Syndrome
autoantibodies (IgG) against anticoagulant phospholipids = inc coag activity
recurrent venous and arterial thrombosis
recurrent fetal loss
thrombocytopenia
Thrombocytopenia
platelet count <150,000
commonly causes leukemia, splenomegaly (sequestration), and autoimmune responses
_____ bleeding seen in platelet disorders
Superficial
petechia, purpua, ecchymosis, gingival bleeding, epistaxis
Drug-Induced Thrombocytopenia
antigen-anitbody response that results in plt destruction
Treat by D/C drug and plt count increases
Heparin-Induced Thrombocytopenia (HIT)
person develops antibodies to plt Factor 4 = activates platelets = thrombosis
can occur with increased levels of serotonin
Stop heparin and give direct thrombin inhibitor
Immune Thrombocytopenia Purpura (ITP)
autoimmune cell d/o = T-cell dysfunction
plt antibody formation and excess destruction of plts
platelets do not aggregate = bleeding
Clinical Manifestations of ITP
ecchymosis bleeding from gums epistaxis melena splenomegaly (spleen is site for plt destruction)
Treatment for ITP
if no symptoms = no treatment
can give steroids (suppress immune response)
infuse plts
IV gamma globulin (slows rate of plt destruction, temp fix)
Thrombotic Thrombocytopenia Purpura (TTP)
Deficiency of enzyme Adam T513 that degrades vWF
more thrombosis than bleeding
EMERGENCY = wide spread occlusions
thrombocytopenia + hemolytic anemia + neuro abnormalities
Clinical Manifestations of TTP
purpura petechia vaginal bleeding neuro symptoms - altered LOC, seizures jaundice (inc bilirubin)
Treatment for TTP (emergent)
Plasmapheresis
FFP
Give missing enzyme
von Willbrand Disease
deficiency or defect in von Willebrand Factor (vWF)
affects both primary and secondary hemostasis
lacking plt function, not plts
DDAVP (synthetic vasopressin)
treatment for von Willebrand Disease
stimulates endothelial cells to release vWF
Hemophilia A
Deficiency or defect of Factor VIII
affects BOTH intrinsic and extrinsic pathways
see increase in both PTT and PT
Clinical Manifestations of Hemophilia A
deep, systemic bleeding
soft tissues, GI tract, joints
joint bleeding can be seen in children when they start walking
Hemophilia B
Deficiency of Factor IX
involved in intrinsic pathway = PTT will be elevated
Factors II, VII, IX, X, prothrombin, and protein C require ______ to convert to their active form
Vitamin K
Disseminated Intravascular Coagulopathy (DIC)
widespread coagulation and bleeding = thrombo-hemorrhagic disorder
Intrinsic Causes of DIC
activation d/t severe endothelial damage
viruses/bacteria, hypoxia, acidosis, shock, hypo/hyperthermia
Extrinsic Causes of DIC
release of extensive tissue factor
OB complications, trauma, burns, sepsis, cancers
Erythroblastosis Fetalis
hemolytic disease that occurs in Rh positive newborns of Rh negative mothers
Hydrops Fetalis
mother’s immune system causes baby’s RBCs to break down = anemia
see splenomegaly and hepatomegaly
Kernicterus
abnormally high levels of unconjugated bilirubin (toxic)
results in severe brain damage or death
Hemodilution
caused by movement of fluid into the intravascular space in hypovolemic conditions
Iron Deficiency Anemia
microcytic, hypochromic anemia
a deficiency in iron leads to dec Hgb synthesis = impairment of O2 delivery
more RBCs are produce in response to low O2
Iron is absorbed in _____
the duodenum of the small intestines
Populations that lose more and require more iron consumption
pregnant females, menstruating females, and children and adolescents
Total Iron Binding Capacity (TIBC)
not usually able to be measured
elevated/measurable in IDA because it is not bound to iron
____ enhances the absorption of iron
Vitamin C
Clinical Manifestations of Iron Deficiency Anemia
fatigue, pallor palpitations/tachycardia, angina dyspnea cheilosis smooth tongue pica koilonychia
Poikilocytosis
abnormally shaped cells
Anisocytosis
different sized cells
Vitamin B12
essential for DNA synthesis and RBC maturation
absorbed in the ileum
only derived from animal products
Parietal gastric cells
secrete hydrochloric acid and intrinsic factor
Need _____ to extract Vitamin B12 from fod
hydrochloric acid
Need ____ to absorb Vitamin B12
intrinsic factor
Achlorhydria
very little hydrochloric acid
seen in pernicious anemia
Pernicious Anemia
autoimmune process where anitbodes react to parietal gastric cells = breaks up the IF-B12 complex
Vitamin B12 Deficiency Anemia
Decreased intake of vitamin B12 (alcoholism, vegans)
Malabsorption (gastric bypass, ileal resection, IBS)
Risk Factors for Pernicious Anemia
long term use of PPIs & H2RAs celiac disease gastrectomy or gastric bypass ileitis vegetarians/vegans
Clinical Manifestations of Pernicious Anemia
paresthesia, lack of coordiantion palpitations/tachycardia, angina can lead to HF N/V/anorexia, wgt loss gingival bleeding, glossitis, jaundice
Glossitis
smooth, beefy red tongue
Schillings Test
most definitive test for pernicious anemia
Folic Acid
essential for formation and maturation of RBCs and synthesis of DNA
Folic Acid Deficiency Anemia
increased in alcoholism, tumors, and certain medications
Clinical Manifestations of Folic Acid Deficiency
same as B12 with more severe GI symptoms
no neuro symptoms
Aplastic Anemia
primary condition of bone marrow stem cells - unable to produce mature cells
see pancytopenia = pallor, fatigue, weakness
Sickle Cell Anemia
results from a point mutation in the beta chain of hemoglobin molecule (HbS)
glutamic acid is replaced with valine
affects black American after 6 months of age
HbS becomes sickle-shaped with…
deoxygenation or low O2 tension
stress, physical exertion, cold, infection, dehydration
hypoxia, acidosis
Acute Chest Syndrome
vaso-occlusive crisis that is the leading cause of death in sickle cell anemia
Thalassemia
group of inherited d/o of Hbg synthesis due to absent of defective synthesis of the alpha or beta chains of HbA
the unaffected chain continues to synthesize, builds up in cell, and interferes with maturation/function
Alpha Thalassemia
gene deletion that results in defective alpha chain synthesis
most common among Asians
Hydrops Fetalis Syndrome
most severe form of alpha thalassemia that occurs in infants (no alpha globin genes)
Hb Bart is formed = high O2 affinity & does not release to tissues
results in death in utero or shortly after
Beta Thalassemia
defect in the beta chain synthesis = excess alpha chains are denatured in Heinz bodies
Manifestations of Beta Thalassemia
growth retardation
bone marrow expansion = chipmunk facies
splenomegaly and hepatomegaly
Heinz bodies
denatured alpha chains that impair DNA synthesis and damage RBC membranes
_____ is a major complication of beta thalassemia
iron overload
Inherited Enzyme Defect G6PD
X-linked recessive d/o that makes RBCs and Hgb more vulnerable to oxidation (usually from medications) = inactive form of Hgb with low O2 affinity
Oxidative Drugs
aspirin, sulfonamides, nitrofurantoin, dapsone, quinidine
Hematocrit greater than ____ can lead to hypoxia
> 60%
Primary Absolute Polycythemia (Polycythemia Vera)
pathologic - occurs irrespective of body’s needs
increase in RBCs, Hgb, Hct, WBCs, platelets
treat with periodic phlebotomy
Complications of Polycythemia Vera
increased blood viscosity
Thromboembolism
Hemorrhage
Secondary Absolute Polycythemia
physiologic increase in erythropoietin level
frequently a compensatory response to hypoxia
seen in high altitudes, chronic heart or lung dx, smoking
Infectious Mononucleosis
caused by Epstein Barr virus
“kissing disease”
leukocytosis (EBV attaches to B cells)
Clinical Manifestations of Mono
prodromal period precedes occurence
fever
pharyngitis (palatal petechia)
lymphadenopathy
Complications of Mono
Hepatitis
Splenomegaly (concern for rupture)
Monospot
detects EBV antibodies
can have false negative if done too early
Serologic tests for Mono
detects rise in IgG and IgE - occurs early
