CBC and Urinalysis Flashcards
When to order CBC (3)
- Screening for anemia
- Suspected hematological disorder
- Toxic child
RBC size (3)
- Normocytic –> RBC size is normal but there is not enough of them (anemia)
- Microcytic –> RBC size is smaller than normal
- Macrocytic –> RBC size is larger than normal
Microcytic, Hypochromic (3)
- Many RBCs smaller than nucleus of normal lymphocytes, increased central pallor
- Occurs with iron deficiency, thalassemias, anemia of chronic disease.
- The red cells tend to be very small and have central pallor
MCV: Mean Corpuscle Volume (6)
- Helps you determine size of red cell
- Determining low of normal
- Age (years + 70)
- Only used between 2-10 years old
- So lower limit of normal is 70
- Upper limit of normal is 90 - Ex: If child is 2, lower limit is 72
- If child is 10, lower limit of normal is 80
RDW: Red Cell Distribution Width (4)
- Coefficient of variation of the red cell volume distribution
- How much do the red cells look like each other?
- When RDW is elevated, cells don’t look like each other
- When RDW is low or normal, ells look like each other
Mentzer Index (3)
- Determined by MCV/RBC
- Value greater than 13 suggests iron deficiency
- Less than 13 it suggests thalassemia.
Calculating Hct from Hgb
Hct = 3 x Hgb
MCH vs. MCHC
- MCH: Amount of HgB/RBC
- MCHC: Portion of RBC occupied by HgB
- CHR =Retic - He
Red Cell Line Shape vs. Size
Shape = RDW
Size = MCV
RBC Rule of 3’s
- Hemoglobin is 3x RBC
- Hematocrit is 3x Hgb
- The lower limit of normal for the hemoglobin is 11 + (0.1 x age in years)
Seventy Plus One Rule
70 + (age in years) is the lower limit of normal for MCV
RDW Levels (3)
- Normal: 11-14
- Thalassemia: slightly over upper limit by 1-2 points or normal
- Iron deficiency anemia: 14-25 (very elevated)
CHr (Advia) Or Retic-He (Sysmex) (4)
- This value measure the amounts of hemoglobin in reticulocyte
- Normal value is > 28 picogram (pg)
- This is a measure of iron available for producing new RBC’s
- Value is reduced in iron deficiency and thalassemia
Causes of Microcytic Anemia
- Most common: Iron deficiency and Thalassemia
- Less Common: Hemoglobin C disease, Hemoglobin D disease, anemia of inflammation, hereditary pyropoikilocytosis (lead poisoning)
- Rare: Sideroblastic anemia, Copper deficiency, Pyridoxine deficiency
Causes of Iron Deficiency Anemia: Decreased Absorption (6)
- Achlorhydria (production of gastric acid in the stomach is absent or low)
- Celiac disease
- Competing metal
- Iron deficiency
- Clay
- Starch
Causes of Iron Deficiency Anemia: Increased Loss (9)
BLEEDING
- GI
- GU (menses, hemosidinuria)
- Lung (pulmonary hemosiderosis)
- Joints (hemarthroses)
- Factitious
- Pregnancy
- Frequent blood donation
- Newborn exchange transfusion
- Iatrogenic
Differential Dx of Normocytic Anemia
- Blood Loss
- Decreased RBC Production
- Ex: bone marrow isn’t working adequately - Increased RBC Destruction
Physiological Anemia of Term Infant (3)
- Anemia in the first 2-3 months of life
- Not due to iron deficiency
- Does not respond to iron therapy
Physiological Anemia of Pre-Term Infant
Appears at 1-2 months of age and is often more severe
Normochromic Anemias (5)
- Hereditary Spherocytosis
- Hereditary Elliptocytosis
- G6PD deficiency
- Aplastic anemia
- Acute blood loss
Macrocytic Anemias (4)
a. Vitamin B12 deficiency
b. Folate deficiency
c. Liver Disease
d. Loss of reticulocytes (due to hemolysis)
Anemia Lab Values: Electrophoresis (5)
- Iron deficiency anemia: normal
- Thalassemia: increased HbA2 or F
- Chronic inflammation: normal
- Lead poisoning: normal
- Sickle Disease: HbSS
Anemia Lab Values: ESR (5)
- Iron deficiency anemia: normal
- Thalassemia: normal
- Chronic inflammation: increased
- Lead poisoning: normal
- Sickle Disease: low
Anemia Lab Values: Smear (5)
- Iron deficiency anemia: hypochromic, target cells
- Thalassemia: normocrhomic, microcytic
- Chronic inflammation: varies
- Lead poisoning: basophilic stippling
- Sickle Disease: sickle cell
Factors that Interfere with Normal WBC (4)
- Age- High neutrophil count during first several days of life
- Race - African Americans have lower WBC
- Minor Illness
- Widely variable leukocyte count
- Neutropenia is not uncommon during a viral illness - Measurement Method: inherent errrors
Neutrophils (8)
- First line of defense against bacterial infection
- Major function are phagocytosis and killing microorganisms via enzymatic degredation
- High in first few days of life, Decrease rapidly after birth within first few days
- On the lower side in infancy (20-30% of circulating WBC) - At age 5 years old, equal neutrophils and lymphocytes
- At puberty, reaches 70% predominance found in adult
- Most abundant type of WBC
- Can see granules when stained
- Band is the immature neutrophil; Is an acute phase response; goes up with severe infection
Neutropenia vs. Neutrophila Shift
Neutropenia: shift to the right
Neutrophila: excess neutrophils; shift to the left
Calculating ANC
ANC = (Neutrophils + Bands Percentage)(Total WBC Count)
Ex: What is the neutrophil count if WBC is 4,500, with 2 bands, and 10 neutrophils?
ANC= (10+2)(4,500)= (.12%)(4,500)= 540
*Make sure to make neutrophils + bands a percent!
Neutropenia Classifications (5)
- In African Americans, 30% may have 1,000 as normal
- Caucasian: 1,500-8,000 normal
- Mild Neutropenia: 1,500-1,000
- Moderate Neutropenia: 1,000-500
- Severe Neutropenia:
Causes of Increased Neutrophils (7)
- Physiological: newborn, stress, exercise
- Acute hemorrhage
- Acute bacterial infection
- Metabolic derangement - diabetes, acidosis, anoxia, burn, seizures
- Drugs – epinephrine, steroids, lithium
- Connective tissue disease – JIA, IBS
- Hematological disorders – cancers, hemolysis splenectomy
Neutrophil and Lymph Evaluation (3)
- Shift to the left: an increase in the number of immature neutrophils (bands and metamyelcote >5% bands)
- Absolute lymphocytosis
- Physiologic → 2 months-4 years
- Increased in Pertussis, TB, Mononucleosis, CMV, Measles, Adenovirus, Syphilis - Lymphopenia
Lymphocytes (3)
T and B cells
- Coordinate/execute immune response via release of inflammatory cytokines
- Bone marrow/thymus are primary lymphoid organs
- Secondary organ is spleen
Lymphocytosis (with causes) vs. Lymphopenia
Lymphopenia: less than 1,000
Lymphocytosis: over 5,000
- Response to acute viral infections
- Chronic infectious states such as TB, Syphillis
- Also seen in ALL, Non Hodgkin’s Lymphoma
Leukocytes (5)
- Large cells with blue-gray cytoplasm
- Reniform (kidney) shaped (i.e. folded nuclei)
- Efficient at digestion of fungi and microbacteria
- Return of Monocytes precedes return of neutrophils by 1-2 days
- May see some monocytosis when child is recovering from an infection
Basophils (6)
- Contain large cytoplasmic granules and sulfated acidic proteins
- Express IgE receptors
- Main function is allergy
- Type I allergic reaction – elevated IgE and histamine release - Release histamine when stimulated
- Above 150u/L = basophilia which is associated with hypersensitivity reactions
- Basophilia may also be due to viral infections (Varicella, Flu, TB)
Eosinophils (5)
- Bilobed nucleus with a red granulocyte filled cytoplasm
- Fight parasites
- Control Allergic Reactions
- Eosinophilia (over 500 cells/mm) is usually seen when Eosinophils make up more than 10% of WBC’s
- Hypereosinophilia persisting for months can cause tissue damage
Causes of Eosinophilia (5)
Neoplasm Addison's Disease Asthma/Allergy Collagen Vascular (autoimmune) disease Parasites
Platelet Line (3)
- Life span of platelets is 8-9 days
- One third are sequestered in the spleen
- Normal count is 150,000-450,000
Pseudothrombocytopenia (3)
- Articifially low count due to clumping
- Suspect if there is a low platelet count and patient is well
- Clumps of platelets on a blood film from EDTA specimen; generally from EDTA preservative from purple-top tubes
Platelet Levels and Bleeding (5)
- Over 100,000 - no bleeding
- 50,000-100,000 - mild bleeding with trauma
- 20,000-50,000 - mild cutaneous bleeding
- 5,000-20,000 - moderate cutaneous and mucosal bleeding
- less than 5,000 - potentially severe CNS bleeding
MPV (4)
MPV is Platelet Size
- Normal: 7-10
- Giant: >13
- Due to Inherited Syndrome - Decreased:
Thrombocytosis
acute phase reactant; platelet count >450,000/mm3
Chediak Higashi Syndrome
WBC morphology
Giant azurophillic granules in lymphocytes
Dohle Bodies
WBC; Bluish cytoplasmic inclusions in neutrophils in bacterial infections, burns, myelodysplasia, pregnancy
In utero hemoglobin (HbF) chains
- Two alpha globin chains
2. Two gamma globin chains
Hemoglobin A (HbA) chains
- Two alpha chains
2. Two beta chains
Hemoglobin A2 chains
- Two alpha chains
2. Two delta chains
Reasons for Ordering Reticulocyte Count (6)
- Normocytic anemia
- Acute blood loss (usually doubling of reticulocyte count in first 24 hours)
- Problems with bone marrow
- Response to anemia therapy
- Infections
- Parvovirus causes aplasia of bone marrow sinc there is no new RBC production for 7 days - Drugs causing hemolysis or bone marrow aplasia
Reticulocyte Production Index (6)
- Corrects the reticulocyte count for the degree of anemia
- Evaluates whether the bone marrow’s response is appropriate
- Percentage; number of reticulocytes as a percentage of the RBCs
- With anemia, the patient’s red blood cells are depleted, creating an enormously elevated reticulocyte count
- Reticulocyte production should increase in response to any loss of RBCs
- Increase within 2-3 days of hemorrhage; will peak in 6-10 days
Two ways to calculate RPI
- RPI = (reticulocyte count x patient’s hemoglobin)/(normal hemoglobin x 5)
- RPI = (Hematocrit/Normal Hematocrit)
RPI Percentages (3)
- RPI >3: Increased production of reticulocytes suggesting either hemolysis or blood loss
- RPI
Lab signs of hemolysis
- Increased lactate dehydrogenase (LDH)
- Increased unconjugated bilirubin
- Decreased serum haptoglobin
- RBC indices demonstrate an increase in MCHC
Normal urine pH
4.5-8.5
Alkaline urine with causes (4)
> 7.0
- Bacteriuria (UTI)
- Renal failure
- Presence of antibiotics, sodium bicarbonate
- Diet high in vegetables, citrus fruits and dairy products
Nitrite and Leukocyte Esterase Dipstick (3)
- Negative nitrite result does not rule out UTI (poor sensitivity)
- Positive result is likely true-positive
* High specificity - Leukocyte esterase
* More sensitive (positive in disease) indicator of infection than nitrates
* Better when tested using catheterized, rather than a bagged specimen
Urine Dipstick: Glucose/Bilirubin (3)
- Urine should not contain glucose
- False positive can occur with ascorbic acid
- Most common reason for positive bilirubin is old or poorly sealed dipsticks
Urine Dipstick: Protein Levels (5)
Measures Albumin
- Trace (about 15mg/dL)
- 1+ = about 30mg/dL
- 2+ = about 100mg/dL
- 3+ = about 300mg/dL
- 4+ = 2,000 mg/dL or greater
Dipstick Interpretation with Proteinuria (2)
- If the urine sample as specific gravity of less than or equal to 1.015, then 1+ is considered positive
* If urine is dilute, then 1+ is positive - If the urine specimen has a specific gravity of greater than or equal to 1.015, then greater than or equal to 2+ is positive
* If urine is concentrated, then 2+ is positive
Urine Protein/Creatinine Ratio
Normal ratio is
Urine Albumin/Creatinine Ratio (3)
- Normal albumin secretion is less than 20 mg/d
- 30-300 mg/d is abnormal and not detected by dipstick = microalbuminuria
- Ratio of > .03 mg of albumin per milligram of albumin is abnormal
Normal range of urine specific gravity
1.005-1.030
Asymptomatic Microscopic Hematuria
In cases of asymptomatic microscopic hematuria, do a spot urine to determine ratio of calcium to creatinine
*Most common cause is hypercalcuria
Ferritin
Measure of iron levels and is an acute phase reactant
*Can be high with inflammation and infection
When is FEP elevated? (3)
Lead poisoning
Chronic disease
Iron deficiency
Causes for acidic urine (6)
Less than 7
- Acidosis
- Presence of certain drugs
- Out of control DM
- Starvation
- Diarrhea
- High-protein diet
