DM: LAB STUDYGUIDE

What is a hemolysis interference pre-analytical error?

RBCs breakdown and release hemoglobin into tube, turns red

What is a Icteric interference pre-analytical error?

Serum appears yellow due to high bilirubin

What is a lipemic interference pre-analytical error?

Serum appears milky or turbid due to high lipids

What can also induce pre-analytical errors in lab testing?

Medication

What is the reference range?

Normal value compared to healthy patients

What is the desirable range?

Associates laboratory levels with clinical outcomes

What is a therapeutic range?

Window, low end is minimum effective dose and high end is toxicity

What is plasma collection

Cell free liquid part of the blood that has been treated with anti-coagulants

What is serum collection

Liquid part of the blood after coagulation, does not have to have clotting factors

What are plasma tubes

Contains anticoags, fill blue top, 9:1 ratio of anticoags to blood

What are serum tubes

Do not have coags

Allows blood to clot

Centrifuges and sample collected from serum

What lab can be diagnostic for acute pancreatitis

Lipase > 3x ULN and amylase elevation

What are the lab findings for chronic pancreatitis

Amylase and lipase may not be realistic

What is the acronym for the Glasgow criteria for acute pancreatitis

Pa O2

Age

Neutrophils

Calcium

Renal function

Enzymes

Albumin

Sugar

What does a higher Glasgow score indicate for acute pancreatitis

Worse prognosis

What is the tumor marker for pancreatic cancer?

CA 19-9

How often should a T2DM patient test their A1c if on insulin

Every 3 months

How often should a T2DM patient test their A1c if not on insulin

Every 3-6 months

How often should a T2DM patient test their lipids, creatinine, and urine microalbumin?

Annually

When should we screen moderate risk mothers for gestational diabetes

End of second trimester

Who can we skip for gestational diabetes screening

Low risk mothers (Caucasian, under 25, no RF)

Who can we screen earlier for gestational diabetes

High risk mothers

What is the initial screening for gestational diabetes

50g OGTT

If the initial gestational diabetes screening is abnormal what is the next step

Retest with 100g bolus

What are the lab findings in DKA

Low pH

Normal or low pCO2

<22 HCO3 (low)

What is the primary disturbance in metabolic acidosis

decreased HCO3

What is the compensatory mechanism in metabolic acidosis

hyperventilation (decreased pCO2)

What finding in a UA can indicate DKA

Positive ketones

Thyroid panel findings in primary hyperthyroidism

Low TSH

High T4

High T3

Thyroid panel findings in secondary hyperthyroidism

High TSH

High T4

High T3

Thyroid panel findings in primary hypothyroidism

High TSH

Low T4

Low/normal T3

Thyroid panel findings in secondary hypothyroidism

Low TSH

Low T4

Low T3

What is the most sensitive 1st line screening test for thyroid abnormalities

TSH

What will you see on a smear in AML

Blast cells with auer rods

If a bone marrow biopsy shows more than 20% myeloid blasts what does this diagnose

AML

What will you see on a smear in CML

Basophils and eosinophils

What chromosome is associated with CML

Philadelphia chromosome

What will a CBC show in ALL

Large number of lymphoblasts

What do we diagnose if >20% lymphoblasts on bone marrow biopsy

ALL

What is the best first line diagnostic for MM

Protein electrophoresis on urine or serum

What condition will have both Bence jones proteins and rouleaus

Multiple myeloma

What are smudge cells pathognomonic with

CLL

What does a peripheral smear look at

Morphology of blood cells under a microscope

What does ELISA do?

Detects antigens and antibodies

What does flow cytometry do?

Sorts peripheral blood cells by size and screens for specific cell markers

What does CBC count do?

Peripheral smear findings in acute bacterial infection

Left shift with increased neutrophil band cells

What is protein electrophoresis used for?

Identify monoclonal antibodies

Peripheral smear findings in viral infection

Lymphocytes and monocytes

Peripheral smear findings in allergies

Eosinophils and basophils

Peripheral smear findings in parasitic infections

Eosinophils

Peripheral smear findings in MONO

Lymphocytes

Peripheral smear findings in leukemia

Lymphocytes

What are Reed-Sternberg cells found in?

Hodgkins lymphoma

What condition is described as excess lymphocytes without immature cells

Non-Hodgkins Lymphoma

Leukemia buzz words - children

ALL

Leukemia buzz words - Auer Rods

AML

Leukemia buzz words - Philadelphia chromosome

CML

Leukemia buzz words - smudge cells

CLL

What is the multiple myeloma buzz word

Plasma cells

What is erythrocytosis

Persistent elevation in RBC mass

What is considered erythrocytosis

Hg >18.5 in men and >16.5 in women

Etiology of erythrocytosis

Myeloproliferative neoplasm

Smoking

Altitude

EPO producing neoplasm

What type of hemoglobin is found in neonates

Fetal hemoglobin (HbgF)

2 alpha 1 gamma units

What type of hemoglobin is see in adults

Adult hemoglobin (HbgA)

2 alpha units 2 beta units

What type of hemoglobin dominates in children

HbgA

What does the G6PD usually do

Protects RBCs from oxidation

What is seen on smear in G6PD def

Heinz bodies and bite cells

Risk factors for G6PD def

Fava beans

Macrobid

Antimalarial

MCC of anemia in the world

Ida

Labs in IDA: Iron Study

Low: ferritin, serum iron, and %transferrin sat

High: TIBC

Labs in IDA: CBC

CBC: ↓ RBC, ↓ Hgb, ↓ MCV, ↓ MCHC can see elliptocytes

Sx of IDA

Pica

Koilonychias

Atrophic glossitis

Esophageal Webs

MCC of lead poisoning

Environmental exposure

Pathophysiology of lead poisoning

Inhibits heme synthesis in maturing erythrocytes which decreases their survival

CBC of lead poisoning

Low MVC and MCHC

What is basophilic stippling seen in?

lead poisoning

What deficit is seen in thalassemia

Production of a and b hemoglobin

CBC of thalassemia

Low MCV and MCH

Normal RDW

Definitive Dx for thalassemia

HbG electrophoresis

Know the anemias *******

We just took a CM exam on this if you doing know it your probably ****ed anyway

What is the criteria for HIT

Thrombocytopenia within 5-10 days of heparin treatment

Platelet count decreased by >50% post exposure

Confirmation test for HIT

Detection of hep-PF4 ab on ELISA

What clotting factors does PT evaluate

III and VII

What clotting factors does PTT evaluate

VIII, IX, XI, XII

Which pathway does PT measure

extrinsic

What pathway does PTT measure

intrinsic

What is the thrombin time

measures conversion of fibrinogen to fibrin

When is fibrinogen low

The clotting cascade is activated

What is D-dimer

fibrin degradation product

When is a D-dimer elevated?

Clots are present

Which clotting time is elevated in Factor IX deficiency

PTT

Which deficiency commonly results from warfarin treatment

Vitamin K

Which factors need vitamin K?

II, VII, IX, X

Which medication is a vitamin K antagonist

Warfarin (Coumadin)

What do we use for Coumadin monitoring

PT/INR for factor VII

PTT for II and X

Are you going to see high or low fibrinogen in DIC

Low

Which thrombotic disorder has neurological sx

TTP (mini strokes dude)

Indications for RBC transfusion

Hgb <7

Indications for platelet transfusion

<10,000/mL