Lab and Diagnostics Exam 2

CMP (Comprehensive Metabolic Panel)

What laboratory panel consists of a BMP plus liver function and protein markers?

BMP + albumin, total protein, bilirubin, AST, ALT, and alkaline phosphatase

What additional tests are included in a CMP but not a BMP?

Assessment of liver disease or protein abnormalities

What is the major indication for ordering a CMP instead of a BMP?

Chemistry panel, metabolic panel, or Chem 14

What are alternative names for the CMP?

Electrolytes, chemistry studies, and enzyme tests

What are the three major categories of CMP components?

Sodium, potassium, chloride, bicarbonate, and calcium

What electrolytes are included in the CMP?

BUN, creatinine, albumin, total protein, bilirubin, and glucose

What chemistry studies are included in the CMP?

AST, ALT, and alkaline phosphatase

What enzyme tests are included in the CMP?

Venipuncture

What procedure is required to obtain a CMP?

Albumin and globulins

What proteins make up total protein?

Maintenance of plasma oncotic (osmotic) pressure

What is the primary function of albumin?

Albumin

What protein level is useful for predicting prognosis in hospitalized patients?

Hypoalbuminemia

What term describes decreased serum albumin?

Cirrhosis, alcoholism, and liver disease

What liver conditions commonly cause hypoalbuminemia?

Nephrotic syndrome

What renal disease commonly causes hypoalbuminemia?

Crohn disease

What GI disorder may cause hypoalbuminemia?

Burns and severe skin disease

What integumentary conditions may lower albumin?

Starvation and malnutrition

What nutritional conditions commonly cause hypoalbuminemia?

Edema

What clinical finding may occur when albumin falls to approximately 2.0-2.5 g

Loss of plasma oncotic pressure

Why does hypoalbuminemia cause edema?

Acute inflammatory and infectious processes

What commonly decrease albumin levels?

Bilirubin

What breakdown product of hemoglobin is measured in the CMP?

Liver

What organ conjugates and removes bilirubin?

Unconjugated (indirect) bilirubin

What form circulates in blood before reaching the liver?

Hemolysis and increased RBC destruction

What causes elevated unconjugated bilirubin?

Neonatal jaundice

What classic condition is associated with elevated unconjugated bilirubin?

Normal liver function and absence of significant hemolysis

What does a normal total bilirubin generally suggest?

Hyperbilirubinemia with jaundice

What laboratory finding should prompt consideration of hepatic, obstructive, or hemolytic disease?

Hepatic jaundice

What type of jaundice results from destruction of liver tissue such as hepatitis?

Obstructive jaundice

What type of jaundice results from blocked bile ducts such as gallstones?

Hemolytic jaundice

What type of jaundice results from excessive RBC destruction?

Sunlight exposure and specimen shaking

What pre-analytic factors may interfere with bilirubin testing?

ALT (alanine aminotransferase)

What liver enzyme is most specific for hepatocyte injury?

Hepatocyte destruction

What does an elevated ALT primarily indicate?

Hepatitis

What disease commonly causes marked ALT elevation?

Metastatic liver tumor

What malignancy may cause mild ALT elevation?

Statins

What common medication class may elevate ALT?

Hemolyzed blood

What specimen problem may falsely affect ALT results?

Obesity

What patient factor may affect ALT levels?

Alcohol-acetaminophen syndrome

What condition can produce extremely elevated ALT values?

AST (aspartate transaminase)

What enzyme is found in liver, heart, skeletal muscle, and kidney?

Cell destruction

What does an elevated AST generally indicate?

Liver disease

What is the most common clinical use of AST?

Myocardial infarction

What cardiac condition can elevate AST?

Nonspecific

Why is AST no longer commonly used as a primary cardiac diagnostic marker?

Statins

What medication class may elevate AST?

Alkaline phosphatase (ALP)

What enzyme primarily reflects cholestasis and biliary obstruction?

Liver, bone, intestine, and placenta

What tissues normally produce alkaline phosphatase?

Hepatocyte destruction

What process is most closely associated with elevated ALP?

Gallstones

What obstructive condition commonly elevates ALP?

Cirrhosis

What chronic liver disease may elevate ALP?

Hepatitis

What infectious liver disease may elevate ALP?

Mononucleosis

What infection may elevate ALP?

Paget disease

What bone disorder classically elevates ALP?

Bone cancer or bone metastases

What skeletal malignancies may elevate ALP?

Pancreatic cancer and lung cancer

What malignancies outside the liver may elevate ALP?

Chronic kidney disease

What chronic medical condition may elevate ALP?

Heart failure

What cardiovascular disease may elevate ALP?

Children, puberty, and pregnancy

What physiologic states normally increase ALP?

Nonspecific marker

Why must ALP be interpreted alongside other laboratory findings?

ALT and AST

What enzymes primarily reflect hepatocyte injury?

Alkaline phosphatase and bilirubin

What laboratory markers primarily reflect cholestasis?

Intrahepatic cholestasis

What type of cholestasis results from liver disease, infection, drugs, hormones, or genetic factors?

Extrahepatic cholestasis

What type of cholestasis results from gallstones, tumors, or cysts?

CMP

What laboratory test evaluates electrolytes, renal function, glucose, liver function, and protein status simultaneously?

Liver disease evaluation

What is the highest-yield clinical application of the CMP compared with the BMP?

Complete Blood Count (CBC)

What laboratory panel evaluates blood cell number, variety, percentage, concentration, and quality?

One of the most frequently ordered laboratory tests

What makes the CBC clinically valuable?

Not generally used as a screening test

What is an important limitation of the CBC?

Evaluation of anemia

What is one of the most common indications for ordering a CBC?

One venipuncture with multiple clinically useful results

What is the major advantage of a CBC?

White blood cell count, red blood cell count, hemoglobin, hematocrit, RBC indices, and platelets

What are the major components of a CBC?

Differential

What CBC component identifies the relative percentages of individual white blood cell types?

Hematopoiesis

What process produces all blood cells from hematopoietic stem cells?

White blood cells (leukocytes)

What blood cells fight infection and participate in immune defense?

Phagocytosis

What major immune function is performed by many leukocytes?

Severity of disease process

What can WBC count help estimate when interpreted with clinical findings?

Pain

What factor may falsely increase WBC count?

Labor

What physiologic condition may increase certain WBC populations?

Red blood cells (erythrocytes)

What blood cells transport oxygen and carbon dioxide?

Hemoglobin

What molecule gives blood its red color and carries oxygen?

Adequacy of erythrocyte production

What does the RBC count help assess?

Hemoglobin

What CBC value best reflects oxygen-carrying capacity?

Anemia screening and monitoring

What is the major clinical use of hemoglobin measurement?

Packed red blood cells (PRBCs)

What blood product is transfused when treating significant anemia?

Hematocrit

What CBC component measures RBC mass?

Centrifugation

How is hematocrit measured?

Hemoglobin, hematocrit, and RBC count

What three CBC values are most useful in evaluating anemia?

Mean corpuscular volume (MCV)

What RBC index measures average erythrocyte size?

Mean corpuscular hemoglobin (MCH)

What RBC index measures average hemoglobin weight per RBC?

Mean corpuscular hemoglobin concentration (MCHC)

What RBC index measures average hemoglobin concentration within RBCs?

Red cell distribution width (RDW)

What RBC index measures variation in RBC size?

Microcytic, normocytic, and macrocytic

What categories are determined by MCV?

Hypochromic

What term describes a low MCHC?

Monitoring anemia therapy

What is the most useful application of MCHC?

Diagnosing severe anemia

What is the primary use of MCH?

Elevated RDW

What finding indicates significant variation in RBC size?

Iron deficiency anemia

What anemia classically produces an elevated RDW?

Sickle cell disease

What hemoglobinopathy commonly produces an elevated RDW?

Acute blood loss

What anemia often has a normal RDW?