heme Flashcards
Blood Formation
Starts as stem cells
Ability to transform into more than one type of blood cell
Every blood cell in the body arises from a stem cell
Hematopoiesis (blood formation)
Complete Blood Count
Red blood cell (RBC or erythrocyte)
Blood cell that carries oxygen
Hematocrit (HCT)
Volume of the blood that consists of rbc’s
Dependent on age and sex (after adolescence)
Hemoglobin (HGB)
Protein molecule in RBC’s
Carries/transports oxygen from the lungs to the body’s tissues
Returns carbon dioxide from the tissues back to the lungs
White blood cell (WBC or leukocyte)
Infection-fighting cells in the blood Platelets (thrombocytes)
Help to clot blood
MATURE RED BLOOD CELL- what number?
(mature at 12)
Contains Hemoglobin
Transports Oxygen to tissue and Carbon Dioxide away from tissue (Gas Exchange)
Stored in bone marrow, liver, spleen
HGB count
Neonate 15-20 g/dl
2 mo and older 12-15 g/dl
RETICULOCYTES - when do they increase?
immature red blood cells
Reticulocytes comprise about 1% of all RBC
Reticulocytes increase in count with chronic anemia or when medications are added to increase RBC and Hemoglobin
babies have more RBC bc
there is bruising from the birth process, can cause hyperbilirubinia.
HEMOGLOBIN F - how long do they last?
RBC with Fetal Hemoglobin has higher affinity with oxygen molecule
Lasts 90 days
ADULT HEMOGLOBIN
Typical RBC with Adult Hemoglobin lasts about 120 days
HGB count
Neonate 15-20 g/dl
2 mo and older 12-15 g/dl
HCT count
Approx 3x HGB
35%-45%
RETICULOCYTES
immature RBC -
Platelets - normal count?
Coagulation
Adhere to one another to plug holes in vessels or tissues where there is bleeding
Releases serotonin to injured tissue
Vasoconstrictor (decreases blood flow to area)
Plt count 150,000-500,000
White Blood Cells - count for babies?
Fights infection
The body’s army
WBC count
Healthy neonate 15,000-20,000
Children >2yrs and Adults 5,000-10,000
Assessment of Hematologic Function
Complete blood count
Decrease in any cell line may indicate disorder r/t bone marrow or immune system
History
Physical assessment
Child’s energy and activity level
Growth patterns
common leukemia in children
(children B leukemia)
pre-B cell
ANEMIA
The most common hematologic disorder of childhood
Decrease in number of RBCs and/or hemoglobin concentration below normal
Decreased oxygen-carrying capacity of blood
Consequences of Anemia
Decrease in oxygen-carrying capacity of blood and decreased amount of oxygen available to tissues
When anemia develops slowly, child adapts
Effects of Anemia on Circulatory System - what about peripheral resistance?
Hemodilution
Decreased peripheral resistance
Increased cardiac circulation and turbulence
May have murmur
May lead to cardiac failure
Cyanosis
Growth retardation
Decreased energy
types OF ANEMIA - NORMACYTIC (NORMACHROMIC) - think norm
NORMACYTIC (NORMACHROMIC)
RBC of normal size and color
Acute blood loss, Hemolysis, Malignancy of bone marrow
INTRA-ABDOMINAL HEMORRHAGE
Causes
Spleen or Liver lacerations
Seatbelts
Contact sports
Physical attacks
Treatment
Surgical Repair or Resection of Liver or Spleen
Observation and Bedrest
Administration of Iron - give it when?
Give in 2 divided doses between meals
Iron is absorbed best in an acidic environment
May add ascorbic acid
Vomiting and diarrhea may occur
If so give with meals and reduce dosage (gradually increase as tolerance develops)
Turns stool green
Lack of color indicates insufficient iron
Liquid preparations stain teeth
administer through a straw and rinse mouth after administration
B12 - give for what?
for pernicous anemia and alcohol
Blood Transfusion Therapy - maximum time to infuse?
Two RN check
Identify:
Donor and recipient blood types and groups
Expiration date
Use appropriate filter
Use blood within 30 minutes of arrival
Monitor vital signs
Transfuse slowly for first 15 to 20 minutes
Infuse over 4 hours maximum
Observe carefully for patient response
Stop transfusion immediately if signs or symptoms of transfusion reaction; notify practitioner
give iron with what?
oj
Transfusion Reactions - which is the most severe?
Hemolytic—the most severe, but rare
Febrile reactions—fever, chills
Allergic reactions—urticaria, pruritus, laryngeal edema
Air emboli—may occur when blood is transfused under pressure
Hypothermia
Delayed Reactions to Blood Transfusion
Transmission of infection
Hepatitis, HIV, malaria, syphilis, other
Blood banks test vigorously and discard units of infected blood
Delayed hemolytic reaction
Manifestations of Circulatory Overload - what color is skin?
Precordial pain (pain near heart)
Dyspnea
Distended neck veins
Cyanosis
Dry cough
IRON DEFICIENCY ANEMIA - what is lacking?
Production of HGB is inadequate
Caused by
Inadequate supply of dietary iron
Malabsorption of iron through GI tract
Chronic blood loss
Premature infants at risk
Last month gestation fetus stores enough iron for 6-12 mo
Adolescents at risk d/t
Rapid growth
Poor eating habits
Girls irregular menses
Iron Deficiency Anemia Treatment - what to use if babies in the first 12 months?
Correct underlying problem
Nutrition is generally is preventable
Breast milk or iron-fortified formula should be used for the first 12 months
SICKLE CELL ANEMIA
A hereditary hemoglobinopathy
Ethnicity
Occurs primarily in African-Americans
Occurrence 1 in 375 infants born in United States
1 in 12 have sickle cell trait
Occasionally also in people of Mediterranean descent
Also seen in South American, Arabian, and East Indian descent
Etiology of Sickle Cell
In areas of the world where malaria is common, individuals with sickle cell trait tend to have a survival advantage over those without the trait (they don’t get sick from malaria!)
Autosomal recessive disorder
1 in 12 African-Americans are carriers (have sickle cell trait)
If both parents have trait, each offspring will have 1 in 4 likelihood of having disease
Diagnosis of Sickle Cell - what part of body to test?
Cord blood in newborns
Newborn screening done in 43 states
Genetic testing to identify carriers and children who have disease
Sickle turbidity test
Quick screening purposes in children older than 6 months
Pathophysiology - sickle cell
Partial or complete replacement of normal Hgb with abnormal hemoglobin S (HgbS)
Hemoglobin in the RBCs takes on an elongated (“sickle”) shape
Sickled cells are rigid and obstruct capillary blood flow
Microscopic obstructions lead to engorgement and tissue ischemia
Hypoxia occurs and causes sickling
Large tissue infarctions occur
Damaged tissues in organs lead to impaired function
Splenic sequestration
May require splenectomy at early age
Results in decreased immunity
Sickle Cell Crisis
Precipitating factors
Anything that increases the body’s need for oxygen or alters transport of oxygen
Trauma
Infection, fever
Physical and emotional stress
Increased blood viscosity due to dehydration
Hypoxia
From high altitude, poorly pressurized airplanes, hypoventilation, vasoconstriction due to hypothermia
Types of sickle cell crisis - occlusive
Vaso-occlusive (VOC) thrombotic or “Painful”
Most common
Stasis of blood with clumping of cells in microcirculation → ischemia → infarction
Signs and symptoms
Tissue engorgement Severe abd pain, thoracic/muscle/bone pain, increased jaundice, dark urine, low-grade fever, pale lips/tongue/palms/nail beds
Types of Crisis sickle cell - acute - where are RBCs trapped?
Acute sequestration
Sudden, massive entrapment of RBC’s in spleen and liver
Life-threatening, death can occur within hours
Signs and symptoms
Profound anemia
Lethargy
Hypovolemic shock
Death
Types of Crisis - sickle cell - aplastic
(a plastic bone marrow is viral)
Aplastic (bone marrow depression)
Diminished production and increased destruction of RBCs
Triggered by viral infection or depletion of folic acid
Pallor, lethargy, sleepiness, dyspnea, possible coma, decreased bone marrow activity, RBC hemolysis
Acute Chest Syndrome (related to sickle cell)
(pneumonia is a cutie)
Similar to pneumonia
VOC or infection results in sickling in the lungs
Chest pain, fever, cough, tachypnea, wheezing, and hypoxia
Repeated episodes may lead to pulmonary hypertension
Prognosis - sickle cell
No cure (except possibly bone marrow transplants)
Supportive care/prevent sickling episodes
Frequent bacterial infections may occur due to immunocompromise
Bacterial infection is leading cause of death in young children with sickle cell disease
Strokes in 5% to 10% of children with disease
Result in neurodevelopmental delay, mental retardation
Therapeutic Management - sickle cell
Focus on prevention of triggers
Aggressive treatment of infection
Possibly prophylactic with oral penicillin from age 2 months to 5 years
Monitor reticulocyte count regularly to evaluate bone marrow function
Blood transfusion, if given early in crisis, may reduce ischemia
Exchange transfusion may be appropriate in some situations
Medications
Analgesics, Droxia (chemotherapy drug), iron supplements
Frequent transfusion leads to hemosiderosis (iron in tissues)
Treat with iron chelation
Parenterally—deferoxamine
Oral—deferasirox or deferiprone
Used alone or in combination
HTSC Transplant
Human tumor stem cell (HTSC)
Potential cure for patients with SCD (sickle cell disease)
Difficult decision for HTSC transplant
Child may face death without the transplant
Preparing the child for transplant places the child at great risk
No “rescue” procedure if complications follow HTSC transplants
Other HSCT Modalities
Umbilical cord blood transplantation
Haploidentical transplants
Nonmyeloablative conditioning regimens
Sibling donor protocols
THALASSEMIA
Inherited blood disorders of hemoglobin synthesis
Classified by Hgb chain affected and by amount of effect
Autosomal recessive with varying expressivity
Both parents must be carriers to have offspring with disease