Hematology

Pediatric Hematology Issues

Blood Components

  • Erythrocytes (RBCs)

    • Carry oxygen and carbon dioxide through hemoglobin (Hgb)

  • Leukocytes (WBCs)

    • Involved in infection control and immunological reactions

  • Thrombocytes (Platelets)

    • Essential for blood clotting

  • Plasma

    • Liquid portion containing coagulation factors

Red Blood Cell Disorders in Pediatrics

  • Biconcave Disc Shape

    • Provides more surface area for gas exchange at periphery

    • Allows cells to slip easily through vascular system

  • Anemia

    • Results from too few normal RBCs

    • Polycythemia: too many RBCs

Main Types of Hemoglobin

  • Normal Human Hemoglobin

    • Hemoglobin A: Normal, 95-98% in a

    • dults (4 chain molecule)

    • Hemoglobin F: Fetal hemoglobin, falls to low levels after birth. Makes up 2% of hbg found in adults (2 chain molecule)

  • Variant of Human Hemoglobin

    • Hemoglobin S: found in sickle cell disease

Anemia

  • Hemoglobin or # of RBCs is reduced below normal

  • Signs & Symptoms

    • Pallor (esp palms & mucous membranes)

    • Jaundice possible, if RBCs break

    • Increased HR, RR

    • Decreased BP, systolic murmur

    • Irritable, tired, poor feeding, anorexia, poor growth

    • Easily fatigued, decreased activity

    • Headache, dizziness, tinnitus

    • Skeletal changes

    • Pica (eating things that aren’t food: ice, paper, chalk)

  • Effect: decrease in oxygen-carrying capacity of the blood & reduction in the oxygen available in to the tissues

  • CBC includes hemoglobin, hematocrit & reticulocyte

  • Rule of thumb: Hbg = 1/3 of hematocrit value when normally hydrated

  • ** Normal Reticulocyte count: 0.5 - 1.5 %

    • what can an elevated retic count tell us?

Anemia: Non-Hemolytic vs Hemolytic Hemolysis

  • Hemolysis- means red cells break (lyse)

  • Non-Hemolytic Anemia

    • decreased production or a loss of red cells

    • Iron Deficiency

      • Folic acid or b12 deficiency

      • CKD

      • Blood loss

  • Hemolytic Anemia

    • destruction of red cell

    • Sickle Cell Disease

      • Thalassemia- inherited; body doesn’t make enough hemoglobin & RBCs

      • Autoimmune Hemolytic Anemia- rare, body produces antibodies that destroy own RBCs

      • Hereditary Spherocytosis- inherited; sphere shaped instead of disc shaped RBCs

      • G6PD deficiency- inherited; body doesn’t have enough of the enzyme G6PD (helps RBCs work)

  • Iron Deficiency Anemia

    • CBC shows microcytic (small, pale RBCs) caused by inadequate iron supply

    • Cause:

      • deficient dietary intake

      • increased demand- growth spurts

      • blood loss: acute or chronic

      • Most common nutritional deficiency in children:

        • 5 months - 2 years: picky eaters

        • Adolescents: growth spurts/bad diets

        • Lower socioeconomic groups & developing countries:

    • Prevention:

      • full term: if breast feeding, for 6 months they have iron stored

      • iron fortified/rich foods by 4-5 months

      • iron fortified formula

      • No cow’s milk before age 1

      • Limit cow’s milk to 10-24 oz/day after 1 year

      • Prescribe elemental iron 2-3 mg/day/kg 1-2 doses a day in low birth-weight infants: last few weeks in utero baby stores iron, when baby is premature they miss out on that

    • Treatment:

      • provide oral iron supplement 1-3 daily doses until Hbg is normal

        • Take WITHOUT milk or dairy

        • Administer w/ OJ

        • Can stain teeth= rinse/wipe

      • Parenteral iron-dextran (if non-adherent to PO Fe)

      • PRBC transfusion- if very low & symptomatic. this is a quick fix (but transfuse slowly over many hours)

Red Blood Transfusions: nurses need to know

  • Red Cells

    • universal donor, universal recipient

    • What type can receive what type?

    • (5 mL/kg will raise Hbg by one gram: fun fact)

    • Rate to transfuse: 5mL/kg/hr (younger) or over 2-4 hrs (school-aged)

  • Nursing Responsibilities

    • 2 pt identifiers when drawing type & cross & hanging blood

    • 2 RNs bedside check of unit & pt- keep slip attached to blood bag

    • Infuse via pump (usually), no meds or fluids concurrently in same line

      • vitals

    • Monitor for reactions: allergies. febrile, hemolytic, septic, mismatch

Sickle Cell Disease (SCD)

  • Genetic

    • Autosomal recessive inheritance, complete penetrance, variable expression

    • Red cell structural issue which causes hemolytic anemia

    • African descent common

    • Lifelong chronic condition w/ acute exacerbations (crises)

  • Newborn screening: ALL US states

  • Diagnosis: blood test or genetic testing

  • 1:12 AA have trait

  • 1:360 AA newborns have disease

  • Complications

    • Splenic sequestration, dactylitis, vaso-occlusive pain crises

Background: Normal RBC vs Sickle RBC

  • Normal RBC

    • Disc-shaped

    • Soft

    • Easily flow through small blood vessels

    • Live for 120 days

  • Sickle RBC

    • Become sickle-shaped during stresses (bc of a genetic code error)

    • Rigid

    • Often get stuck in small blood vessels

    • Only live for 20-45 days

Pathophysiology:

  • What happens:

    • RBC change shape in times of stress into sickle shaped cells. What are stressors?

      • Fever/infection

      • Hypoxia (including high altitudes & hard exercise)

      • Temperature extremes

      • Dehydration

      • Emotional stress

  • What it means:

    • RBCs sickle & un-sickle. but eventually stay in deformed shape & break (hemolysis). Shorter life span- 20-45 days (anemia likely)

    • Sickled cells get stuck in vascular system. Severity, symptoms & threat to life depends on where in body the red cells are stuck

    • Tissues can’t be oxygenated if vascular system is blocked

  • What happens when RBCs sickle?

    • Vaso-occlusive crises

    • Small blood vessels become blocked

    • Less blood reaches area

    • Area becomes painful

    • Risk for ischemic damage

  • Sickle cell crises symptoms depend on the tissue/organ the sickled cells are occluding

    • Muscles, bone marrow: painful vaso-occlusive crisis. Very painful, but not immediately life threatening.

    • Spleen: emergency!!

    • Brain: emergency!!

    • Kidneys: more chronic issues

    • Blood vessels that supply bones: femur/hip problems (avascular necrosis leading to hip replacement(s))

    • Penis: (priapism is a medical emergency!!) repeated priapism from SCD can lead to fibrosis, potential (in long term) for impotence. Can occur in males of all ages (they may not tell anyone- this is dangerous!)

Vaso-occlusive Pain Crises

  • Most common V.O episode is the painful episode

    • pain depends on where the sickled cells are stuck (ex: back muscles, leg muscles, bone marrow)

  • Blockage of small blood vessels by sickled cells leads to decreased oxygen perfusion, ischemia & pain

  • Most painful episodes are not life-threatening, but impact QOL.

  • Painful crises account for most hospitalizations

  • May be precipitated by extreme changes in temp, stress, infection, dehydration, & hypoxia

Education: vaso-occlusive painful episode

  • Try home management first

    • Increased fluid intake: good dilution

    • Apply heat

    • Medicate: NSAIDS, opioids if available already

    • Rest/quiet play

    • Massage

    • Distraction

    • If no relief- refer to ED

    • Pain can be in any part of body

Dactylitis

  • Swelling of hands and feet

    • Also known as “hand-foot syndrome”

    • Seen in children between 6 months and 2 years

    • Can be predicative of severe sickle cell disease

  • Management

    • Aggressive hydration, pain management

Splenic Sequestration: EMERGENCY!!

  • Complication of SCD

    • Trapping of sickled RBCs in the spleen causing spleen enlargement, anemia & a decrease in platelets (platelets also get trapped in spleen)

  • MEDICAL EMERGENCY- rapid drop in hemoglobin & platelets

  • Assessment of spleen size: can’t miss it. Easy to palpate when enlarged. (teach parents)

  • Management

    • Admit to hospital for hydration, pain meds, blood transfusions (given slowly)

  • Splenectomy might be necessary for repeated splenic sequestration episodes.

    • Avoid spleen removal in children under 5 years due to high sepsis risk.

    • Start chronic red cell transfusion therapy under age five.

    • Red cell transfusions on a reg basis keep the % of sickled red cells in body at a safe level of 20-30%. This greatly decreases risk of another splenic sequestration episode

Spleen Function

  • Spleen function is not 100% normal in kids with SCD. (even without complication of sequestration)

  • Risk of pneumococcal sepsis; therefore:

    • Penicillin (PEN VK) given BID under age 5 (with or without spleen)

    • Penicillin given longer if spleen is removed after age 5

    • Vaccines: Meningococcal ACWY, meningococcal B.

SCD: Acute Chest Syndrome

  • Acute illness characterized by fever & respiratory symptoms. May be accompamied by a new pulmonary infiltrate on chest XR.

    • S/S: pain, low pulse ox, increase WOB

    • Majoblor cause of morbidity and mortality.

    • Most common complication of surgery & anesthesia for SCD pt

    • Second most common reason of hospitalization

    • Children have higher incidence, but lower mortality than adults

Acute Chest Syndrome Management

  • Teach: call doctor for:

    • fever

    • chest pain

    • difficulty breathing

    • SOB

    • wheezing or coughing

    • tachypnea

  • Management:

    • blood transfusion

    • oxygen therapy

    • abx

    • incentive spirometry

    • pain meds as needed

    • pre-surgery red cell transfusion to avoid this complication with surgery

Risk: Stroke

  • 10% of kids with SCD experience an infarctive stroke. (20% have silent stroke)

  • Peak incidence is age 2-10 years.

    • Stroke is a medical emergency: stroke protocol!

  • CT or MRI

  • Exchange transfusion: decrease % of sickled cells in circulation (thrombolysis is NOT used)

  • Rehab

  • Enter chronic transfusion program to keep % of sickled cells to low 20s %

  • Stroke Education:

    • When to call:

      • sudden weakness or tingling of an extremity

      • severe headache

      • dizziness

      • visual disturbances

      • loss of balance

      • painless limp

      • changes in behavior or academic performance

    • Primary stroke prevention:

      • Transcranial Doppler (TCD) studies yearly starting at 2-16 years of age

      • MRI studies every other year after 6 years of age: silent strokes- set up any additional learning needs for school

Other Problems

  • kidney damage: difficulty concentrating urine. Enuresis can be a problem

    • what do we normally teach parents to do first for a child w/ enuresis?

  • Avascular necrosis of femur head: hip replacement may be needed by teens-young adulthood

  • Gall stones: may need GB removed

  • Priapism: risk permanent damage for sexual function if repeated episodes. RX with hydration, possibly use needle to dilute out or remove sickled cells from penis

  • Retinal damage leading to blindness: regular eye exams

  • Pulmonary HTN: esp. in adulthood

Sickle Cell Disease: Current Therapies

  • Hydroxyurea

    • Frontline therapy for all kids with SCD beginning at 9 months old

    • Oral chemo drug which increases fetal hemoglobin (Hb F) Fetal hbg red cells do not sickle & have a normal oxygen carrying ability

    • Reduces need for blood transfusions in high-risk patients

    • Reduces the incidence of acute chest syndrome

    • Reduces the number & severity of painful episodes

    • Call with fevers, CBC monitored. Can cause neutropenia. Can’t get script refill without checking CBC

  • Chronic blood transfusion therapy in addition to Hydroxyurea for:

    • Patients w/ history of:

      • Stroke

      • Abnormal TCD (high stroke risk)

      • Debilitating repeated pain crises

      • Recurrent splenic sequestration under age 5

      • Recurrent & severe acute chest syndrome

    • GOAL: shut down the defective RBC production. Chronic transfusions every 3-4 weeks so less defective red cells produced by their own body (20-30% own cells is goal)

Iron Overload

  • Problem when on chronic transfusion therapy

  • Our bodies do not have an innate way to get rid of excess iron. We just store it in organs, which over time does serious damage

    • Serum ferritin level: marker for body iron stores. Checked regularly. Will be abnormally high (normal 20-300 mcg/L… less than 500 mcg/L in these kids is goal & satisfied under 1000 mcg/L

  • Transfused PRBCs are rich in iron, not recycled to make new RBCs when the cells die

  • Need to get iron out of body with drugs called CHELATOR. Iron excreted in urine & stool

    • urine should be rust orange color

Curative Therapy

  • Blood Stem Cell Transplant or Gene Therapy is the only definitive cure for SCD.

    • Candidates usually have severe disease.

    • Prefer a matched, related donor such as an unaffected sibling.

    • Risky: infection, GVHD (systemic disorder occurs when graft’s immune cells recognize host as foreign and attacks body’s cells)

    • Gene therapy trials: going well, in news a lot lately. Several patients cured including children!

Neutropenia

  • There are many causes of neutropenia!

  • Neutrophils job: kill bacteria, protect from infections

  • Neutropenia puts kids at risk for recurrent infections, often caused by their own body flora, but also from outside pathogens. Biggest risk: SEPSIS

  • Normal Absolute Neutrophil Count (ANC): varies by age 3800-4400 (per microliter)

  • Mild neutropenia: 500-1000

  • Severe neutropenia: 0-500

    • Chemo caused neutropenia- 0-200 is considered severe

    • Kids can and do live with a 0 count for several days after chemo

  • Common causes of neutropenia in kids:

    • Congenital (can be transient or permanent)

    • Autoimmune neutropenia: eventually resolves

    • Cyclin neutropenia: with cancer therapy, 7-10 days after first day of chemo, large radiation fields

Neutropenia Nursing Care/Teaching

  • Frequent hand washing

  • Screen visitors for illness

  • Avoid crowds when ANC less than 500 (200 if in cancer therapy)

  • Child should wear a mask: at ANC less than 500 (NCLEX/ATI)

  • No rectal temps, enemas, suppositories! Why?

  • Cook food well done, wash veggies, peel fruit skins, wash cans before opening, no salad bars, pepper, some spices, molds; avoid unpasteurized foods

  • Pets: child should avoid cat/dog/bird feces

  • Good oral hygiene & dental care (ANC > 500 for procedures

  • NO LIVE VACCINES- but siblings can get live vaccines

  • Medications:

    • Pneumocystis Jarevicci Pnemonia prevention: Bactrim, Pentamidine

    • Neutrophil Grown stimulators: G-CSF (filgrastim), GM-CSF (sargramostim)

      • Bone pain, achiness, headache, infection site pain

    • Do we transfuse WBCs? NO. Only in dire, infectious circumstances, extremely rare

Neutropenia with fever: Medical Emergency!!

  • Fever criteria; come to the hospital for:

    • Fever 38.5C (101.3 F) axillary, orally, temporally once OR 3 elevated temps below 38.5 in 24 hrs

    • Do NOT give acetaminophen in that 24 hrs- don’t want to mask a fever

  • Infection work up: look for a source via history & physical (ears, throat, lungs, skin, GI)

  • Draw blood culture start broad spectrum abx (assume sepsis until proven otherwise. blood culture q 24 hrs when febrile)

  • Acetaminophen for fever OK now!

  • Add antifungal if persistently febrile. Add antivirals if warranted (ex: herpes)

  • Remain on abx until full tx course for an identified infection or until ABC over 200 if cyclic neutropenia

Thrombocytopenia

Ecchymoses

Petechiae

Causes of thrombocytopenia: congenital, autoimmune or side effect of chemo/radiation

Low Platelets = Thrombocytopenia

  • Platelets: keep us from bleeding spontaneously, stops bleeding when it starts

    • Normal platelet count in children is 150,000-450,000.

  • Thrombocytopenia is technically defined as a platelet count less than 150,000.

  • Platelet level transfusion threshold is age & diagnosis specific

    • High-risk groups: infants to preschool due to developmental level

    • Kids can live with really, really low platelet counts.

  • Nursing care for children with thrombocytopenia

    • Safety: CNS bleed risk big concern

    • Teaching

    • Transfuse platelets (for chemo induced type)

    • Bleeding management (nose bleeds common, oral mucosa bleeding

    • Med admin in some cases: IVID, steroids, growth factors

Thrombocytopenia PT/Family education: same no matter the cause!

  • Soft tooth brushes or toothettes for oral care

  • NO contact sports

  • Helmet use for toddlers

  • Dealing with epistaxis/bleeding

  • NO ibuprofen- interferes w/ function of platelets

  • Give immunizations SQ not IM or wait until platelet count is at 75k

  • Thrombocytopenia has many causes; know 2:

    • Decreased production:

      • secondary to chemo tx

      • Managed with platelet transfusions, maybe growth factors

    • Increased destruction

      • Immune Thrombocytopenia

        • after a virus, autoimmune destruction of platelets

        • Managed with steroids, IVIG, platelet growth factor (why NOT transfuse platelets in these patients?

        • Can resolve quickly or take up to two years

How do we transfuse platelets?

  • Single donor platelets in children usually transfused (one donor) One unit or ½ unit

  • Random donor plates (many donors, more emergency use)

  • Does not need to be same blood type specific

  • Given over 30 via infusion pump, alone. Never mix with fluids or meds

  • Pay attn to volume (order is by unit. not always volume)

  • Monitoring: pre & post vitals, lung sounds

    • Most common allergic reactions: hives, coughing, wheezing, lip & airway swelling

    • STOP transfusion!!! Give O2!!! Administer epi, diphenhydramine, steroids, H2 Blockers as ordered!!!

Clotting factor disorders

  • vonWillebrand Disease

  • Hemophilia

    • inherited bleeding disorders (majority of the time)

    • X-linked recessive for A&B (70%)

    • 30% of cases are the result of spontaneous chromosomal mutation

  • Hemophilia A: Factor VIII deficiency- gene therapy

  • Hemophilia B: Factor IX deficiency- gene therapy just approved

  • Severity of disease depends on the amount of factor produced (GENE EXPRESSION)

    • Severe: less than 1% normal factor levels, spontaneous bleeding

    • Moderate: 1-5% normal factor levels, bleeding with mild injury

    • Mild: 5-25% normal factor levels, bleeding w/ surgery or trauma

  • Diagnosis

    • atypical bleeding at circumcision or bruising at neonate vaccines

    • Toddlers w/ lip bleeding or unusual bruising when learning to walk

    • Family history of affected males on mom’s side

    • Elevated PT/PTT (Normal 11-13.5/25-35

    • Low clotting factor levels

  • Clinical manifestations (A&B indistinguishable)

    • Hemarthrosis: most common, bleeding into joints

      • Danger: permanent joint damage, fixed, inflexible joints

    • Soft tissue hematomas (ex: muscle)

      • muscle atrophy

      • shortened tendons

    • Other sites of bleeding:

      • Urinary tract

      • Mouth, GI

      • CNS: most concerning, young age biggest risk due to activity

    • Prolonged bleeding after surgery/dental extractions

Hemophilia A & B managing joint & muscle bleeds

  • Damage from repeated bleeding into joints is like that of rheumatoid arthritis

  • Nursing interventions “Factor in RICE”

    • Administer factor replacement therapy

    • RICE (Rest, Ice, Compression, Elevation).

  • Active range of motion is preferred over passive to prevent overstretching and bleeding. Helps maintain mobility, function, long term problems

Hem. A&B TX

  • Factor replacement RX given prophylactically & episodically

  • Replacing clotting factors used to be derived from donating plasma & whole blood

  • HIV from contaminated blood (where the factors came from) in late 1970s, mid 1980s hit these patients worldwide hard; 50% infected, 40% of these died of AIDS

  • Synthetic factors are now standard

    • Risk of developing inhibitors (autoimmune destruction)

    • Would need drugs to treat this complication

  • Clotting factor infusion use

    • Severe hemophilia

      • prophylactic factor infusions given on a weekly schedule to maintain baseline clotting levels.

      • Then, extra “episodic” infusions for injuries, procedures in addition to scheduled proph. factor

      • Given via ports or butterfly needles.

    • Mild-moderate hemophilia

      • prophylactic factor infusions MAY be used until concrete operations developmental level to keep kids safe

      • Otherwise, treat episodically for injury, procedures, surgeries

Clotting Factor Disorder: General Care

  • Monitor clotting times & coagulation studies

  • Factor replacement (prophylactic and/or episodic for injury)

  • Reconstitute & administer factors IV. Do not waste- will give a bit over calculated dose, confirm w/ provider

  • RICE, PT & OT to maintain mobility

  • Monitor for signs of internal bleeding (esp. intracranial!)

  • SQ immunizations, not IM