Hematologic Flashcards
Signs and symptoms of anemia > 10, 8-9. 6-7, 4-5
10- ASX
8-9 - malaise, fatigue, pallor
6-7 - DOE, dyspnea at rest, syncope, bounding pulses (& other si hyperdynamic state (inc CO/circulation))
4-5 - MI, stroke, HOHF, arrhythmias
Can’t just look at numbers - lower the numbers = worse symptoms but the acuity of the drop = worse symptoms & worse cardiac reserve (underlying heart disease) at baseline = worse symptoms
Lg change in hemoglobin/short time = sx
Sm change in Hgb/long time = body compensates slowly
History questions & PE to ask/do when someone comes in SOB or is found to be anemic
Hx: Recent trauma, gingival bleeding, blood in stool, easy bruising, family bleeding disorder, CP, SOB, syncope, pre-syncope If established history of anemia - ever required transfusions before? PE: Palpebral conjunctiva pale? Tachycardic?
RDW Definition
Red cell distribution width (RDW) is a measure of the variation in RBC size, which is reflected in the degree of anisocytosis on the peripheral blood smear. A high RDW implies a large variation in RBC sizes, and a low RDW implies a more homogeneous population of RBCs A high RDW can be seen in a number of anemias, including iron deficiency, myelodysplastic syndrome, and hemoglobinopathies, as well as in patients with anemia who have received transfusions
EPO
EPO is a true endocrine hormone produced in the kidney by cells that sense the adequacy of tissue oxygenation relative to the individual’s metabolic activity As Hct/Hgb drops, there’s an exponential rise in EPO
Reticulocyte
An immature RBC - enucleated but has RNA meshwork ( = granular/reticulated appearance)
Reticulocytes normally survive in the circulation for one day; after this time they lose their reticulum (RNA) and become mature red blood cells. Under steady-state conditions reticulocytes will represent approximately 1 percent of total circulating RBC
3 Examples of how volume status affects Hgb/Hct lab levesl
1. Volume depletion -
Decrease in plasma volume = hemoconcentration = false increase in Hgb/Hct/RBC count. So if anemic pt is admitted dehydrated, it may not show (have normal H/H) until fluids are replenished
2. 3rd Trimester pregnancy -
Similarly increase in plasma volume can dliute values - example = 3rd trimester in pregnancy - RBC volume increases 25% but plasma volume increases 50% - so they have a dilutional or false anemia - pt are not really anemic - if you only look at RBC mass they are actually polycythemic
3. Acute Bleeding -
Someone who has acutely bled will have postural hypotension 2/2 volume deplestion but a normal H/H. Only when fluid shifts from extravascular to intravascular to replete loss will the H/H reflect the blood loss. Therefore if it does not fully replete, the H/H will not fully reflect the amount of blood lost.
Signs of hypovolemia from acute bleed
Early: Fatigability, lassitude, and muscle cramps
This can progress to postural dizziness, lethargy, syncope
In severe cases, persistent hypotension, shock, and death
Note: There is some reduction in blood volume but not plasma volume after acute severe hemolysis, due to the fall in RBC mass. In comparison, total blood volume remains normal in anemia due to chronic, low-grade bleeding since there is ample time for a compensatory increase in the plasma volume via equilibration with the extravascular space and renal retention of salt and water.
Causes of Anemia (3 main)
1. Decreased production (RI <2%) -
Bone marrow suppression, innefective erythropoiesis - (sideroblastic, ACID, thalasemia, folate/B12 def, liver cirrhosis, ETOH, chemo, aplastic anemia)
2. Increased destruction (RI >2%) -
Hemolysis (sickle cell, G6PD def, AIHA, hereditary spherocytosis, paroxysmal nocturnal hemoglobinuria)
3. Blood loss -
Acute hemorrhage vs slow bleed (old man w/ colon CA vs woman w/ mehorrhagia = iron deficiency anemia)
Causes of normocytic anemia w/ normal RI
(& labs negative for hemolysis)
Chronic kidney disease
Leukemia
MDS (myelodysplastic syndrome)
RI < 2%, MCV < 80, Increased iron, nromal ferritin, normal TIBC
Sideroblastic anemia - dz where iron can’t be put into Hgb
Sideroblasts = nucleated RBC w/ ring appearance b/c iron stuck in mitochondria surrounds nucleus
Causes sideroblastic anemia (reversible & irreversible)
Reversible: Drugs, ETOH, Lead
Irreversible: Bc deficiency, MDS
Clinical presentation sideroblastic anemia
Labs to order to evaluate for hemolysis
Haptoglobin (decreased)
LDH (lactic dehydrogenase) (increased)
Bilirubin (increased)
Bilirubin is increased if hemolysis is present b/c heme is broken down into bilirubin - will often be accompanied by si/sx jaudice. Haptoglobin will be decreased because haptoglobin binds free Hgb in the blood so all the haptoglobin is bound up to Hgb instead of circulating. LDH is increased
