Hematologics Flashcards
Anemia definition:
reduction of either the number of RBCs, the amount of hemoglobin, or hematocrit (% of packed RBCs per deciliter of blood)
Definition of Sickle Cell Disease:
genetic disorder that results n chronic anemia, pain, disability, organ damage, increased risk for infection, and early death
Formation of abnormal hemoglobin chains - most common in Af. Americans
In normal hemoglobin, hemoglobin A(HbA) has
two alpha chains and two beta chains of amino acids
98-99% with a small % of fetal form of HbF
In SCD, what % is the total hemoglobin is composed of an abnormal beta chain?
40%
HbS - sensitive to low O2 content of RBCs
The clumped masses of sickled RBCs block blood flow is called what?
Vaso-occlusive event (VOE)
leads to hypoxia
The average life span of ab RBC conatining 40% or more of HbS is about how many days?
10-20 days – causes hemolytic (cell-destroying) anemia in patients with SCD
normal life span of RBCs
120 days
Patients with SCD has periodic episodes of extensive cellular sickling called what?
Crises –lead to hypoxemia (deficit of O2 in blood)
Etiology of SCD
Autosomal recessive pattern of inheritance
Specific mutation on chromosome 11
AS:
Sickle cell trait: occurs when one normal gene allele and one abnormal gene allele for hemoglobin are inherited and only half of the hemoglobin chains are abnormal
History of SCD:
Long sanding diagnosis
Usually has no manifestations other than presence of HbS
-Determine the patient’s energy level using a scale ranging from 0 to 10 to access degree of fatigue
What is the most common manifestation of SCD crisis?
pain
Physical assessments of SCD include:
Cardiovascular changes Priapism Skin changes Abdominal changes Kidney and urinary changes Musculoskeletal changes CNS changes
Cardiovascular changes: SCD
risk for high output heart failure
Priapism: SCD
prolonged penile erection that can occur to men with SCD
Skin changes: SCD
include pallor or cyanosis because of poor gas exchange from decreased perfusion and anemia
plus Jaundice results from RBC destruction and release of bilirubin
Abdominal changes: SCD
damage to the spleen and liver, occurs often early from many episodes of hypoxia and ischemia
Kidney and urinary changes: SCD
common as a result of poor perfusion and decreased tissue gas exchange
Musculoskeletal change: SCD
occur because arms and legs are often sites of blood vessel occlusion
CNS changes: SCD
During crisis, patients may have a low grade fever, if CNS has infarcts or repeated episodes of hypoxia, patients may have seizures or manifestations of a stroke
Assess for presence of “pronator drift” bilateral hand grasp strength, gait, and coordination
Psychosocial assessment: SCD
Often behavior changes are early manifestations of cerebral hypoxia from poor perfusion
Lab assessment: SCD
The diagnosis of SCD is based on the percentage of hemoglobin S on electrophoresis
AS is usually less than 40% HbS, and does not change during crisis
what count is usually high in SCD?
WBCs
Imaging assessment: SCD
Bone changes occur as a result of chronically stimulated marrow and low bone O2 levels
Skull= crew cut appearance on x-ray
x-rays of joints may show necrosis and desruction
MRIs may show soft tissue and organ changes from poor perfusion and chronic inflammation
Other diagnostic testing: SCD
ECGs document cardiac infarcts and tissue damage
-may show cardiomyopahy and decreased cardiac output
Managing pain of SCD:
Mild pain = managed at home
Severe pain = require hospitalization and opioid analgesics
-Drug therapies, hydration, and complementary therapies
Preventing sepsis: for SCD
Continually assess for infection and monitor CBC with differential WBC count daily
Drug therapy
Hydration
O2 is given during crisis
Transfusion possible to help increase HbA levels