Diagnostic Testing

Comprehensive practice vocabulary flashcards covering diagnostic testing, complete blood count (CBC) components, chemistry panels, coagulation tests, cardiac biomarkers, order of draw, specimen collection protocols, culture & sensitivity, and radiology procedures from Nursing 110.

1. CBC (complete blood count)

2. chemistry panel

3. coagulation study

4. organ/disease specific study

5. urinalysis

6. stool specimens

7. sputum specimen

8. drug levels

9. cultures

What are 9 common lab tests?

white blood cells (WBCs), red blood cells (RBCs), platelets, hemoglobin, hematocrit

What factors does a Complete Blood Count (CBC) evaluate?

5,000 - 10,000

What is the normal range of WBCs

Leukopenia

A total white blood cell count of less than $4{,}000/\text{mm}^3$

autoimmune disease, bone marrow suppression, and drug toxicity

what can be causes of leukopenia? 3

Leukocytosis

A total white blood cell count exceeding $10{,}000/\text{mm}^3$

infection and inflammatory responses.

What can be causes of leukocytosis? 2

4.2 - 6.1 million/uL

The normal reference range for circulating erythrocytes (RBCs)

• anemia

• hemorrhage

• kidney disease

What can cause low levels of RBCs? 3

• polycythemia

• severe dehydration

What can cause high levels of RBCs? 2

Polycythemia

An abnormal increase in the concentration of circulating red blood cells or platelets, resulting in elevated laboratory values.

12 - 18g/dL

What is the normal range of hemoglobin?

anemia, hemorrhage, kidney disease

What causes low levels of hemoglobin? 3

COPD, severe dehydration

What causes high levels of hemoglobin? 2

The percentage of total blood volume composed of packed red blood cells, normally $37\text{--}47\%$ in females and $42\text{--}52\%$ in males.

Hematocrit (Hct) Reference Range definition and range in males/females

• anemia

• hemorrhage

• kidney disease

What causes low levels of hematocrit? 3

Platelets (Thrombocytes)

Cellular fragments essential for clotting

150,000 - 400,000

What is the normal range of platelets?

• hemorrhage

• leukemia

• splenomegaly

HIGH RISK OF BLEEDING

What causes a low level of platelets?3 And what does low level of platelets pose risk for?

to show the percentage of each type of WBC in the blood

What is the purpose of a CBC with differential?

• neutrophils

• eosinophils

• basophils

• lymphocytes

• monocytes

What are the 5 types of WBCs

during acute bacterial infections

When are Neutrophils increased

during allergic reactions or parasite infections

When are Eosinophils increased 2

levels increase in leukemia, allergic reactions, and hypothyroidism.

When are Basophils increased 3

increase during chronic bacterial or viral infections (e.g., COPD, HIV).

When are Lymphocytes increased 2

elevate during protozoal infections and viral infections

When are Monocytes increased 2

Potassium (K), Sodium (Na), Chloride (Cl), Calcium (Ca), Bicarbonate (HCO3)

What are key blood chemistry components? 5

Potassium ($K^+$)

The major intracellular cation that regulates cellular water balance, electrical conduction in muscle cells, and systemic acid-base balance. (kidneys and heart)

3.5 - 5.1

low: hypokalemia

high: hyperkalemic

What is the normal range for Potassium?

Sodium ($Na^+$)

The major extracellular cation that maintains osmotic pressure, assists in nerve impulse transmission, and helps regulate acid-base balance. (neuro)

135 - 145

low: hyponatremia

high: hypernatremia

What is the normal range for sodium?

Chloride ($Cl^-$)

The major extracellular anion that indicates hydration status and acid-base balance in conjunction with other electrolytes. (works with sodium)

98 - 106

What is the normal range for chloride?

Calcium ($Ca^{2+}$)

A vital mineral for muscle contractility, cardiac function, neural transmission, and blood clotting; used to evaluate parathyroid function, renal failure, and malignancies. (bones and neuro)

8 - 10

low: hypocalcemia

high: hypercalcemia

What is the normal range for calcium?

Bicarbonate ($HCO_3^-$)

A chemical buffer evaluated to determine pH status and electrolyte status.

• blood urea nirtogen (BUN)

• Creatinine

• ALT

• glucose

• albumin

• total protein

What are 6 key blood chemistry components?

Blood Urea Nitrogen (BUN)

Nitrogen in the blood from waste product urea (produced when protein is broken down). Rough indirect measurement of renal function and liver function

10 - 20

What is the normal range for BUN

• kidney disease

• dehydration

• decreased blood flow to the kidneys

What can cause BUN to be higher than 20? 3

Creatinine

A metabolic waste product used to diagnose impaired renal function and presence of kidney dysfunction. Works with BUN

0.6 - 1.2

What is the normal range for Creatinine?

Alanine Aminotransferase (ALT)

Used to monitor hepatic (liver) function and disease

Glucose

The primary cellular energy source for the body, and is essential for brain and erythrocyte function

Fasting blood glucose levels

used to help diagnose diabetes mellitus and hypoglycemia; instruct client to fast for 8-12 hrs before test

Albumin

A major plasma protein synthesized in the liver that maintains colloidal osmotic pressure, transports drugs, hormones, and enzymes, and serves as an indicator of nutritional status and liver function. (think nutrition/fluid)

low albumin → low protein → skin breakown, poor nutrition, delayed healing

What does it mean when albumin is low?

Total Protein

A laboratory measurement combining prealbumin, albumin, and globulins used to monitor disease status, antibody production, and protein-wasting disorders.

• prothrombin time (PT)

• international normalized ratio (INR)

• activated partial thromboplastin time (aPTT)

• D-dimer

What are important coagulation studies? 4

Prothrombin Time (PT)

A coagulation study assessing extrinsic coagulation by measurement of factors I, II, V, VII, X

11 - 13 sec

How many seconds is a normal range for PT?

• DIC

• liver disease

• vitamin K deficiency

• clotting factor deficiency

What are causes of increased PT?

Warfarin/coumadin

blood thinner

Vitamin K

What is the antidote for warfarin?

International Normalized Ratio (INR)

A standardized calculation derived from PT; calculated by comparing the patient’s PT with a control value

standard patients: 0.8 - 1.1

use of Coumadin: 2-3

patients with an artificial mechanical heart valve: 2.5 - 3.5

What are the norm ranges for:

standard patients

use of Coumadin

patients with an artificial mechanical heart valve

• warfarin therapy

• bleeding disorders

• liver disease

• sudden decrease in vitamin K intake

What are causes for elevated levels of INR? 4

Activated Partial Thromboplastin Time (aPTT)

A coagulation study evaluating intrinsic coagulation by measuring factors I, II, V, VIII, IX, X, XI, XII

30-40 seconds

What is the normal seconds range for aPTT?

heparin (longer range of seconds)

What drug affects aPTT?

Protamine

What is the antidote for heparin

• heparin therapy

• DIC

• hepatic disease

What causes increased aPTT time? 3

D-dimer

A blood test that can help your dr determine if you may have a blood clotting condition where the body is attempting to breakdown blood clots; positive = BAD

• Erythrocyte sedimentation rate (ESR); sed rate or sedimentation rate

• C-reactive protein (CRP)

What are inflammatory markers? 2

Erythrocyte Sedimentation Rate (ESR)

An inflammatory marker used to detect illnesses associated with acute or chronic infection, inflammation, neoplasms, and tissue necrosis or infarction; combined with CRP for diagnoses

C-Reactive Protein (CRP)

An acute-phase reactive protein used to indicate inflammatory events and is believed to have value in predicting coronary events; more sensitive than ESR

• Creatinine Kinase (CK, CPK)

• Troponin

• Myoglobin

• Lipid Panel

What are cardiac lab tests? 4

Creatinine Kinase (CK / CPK)

cardiac lab test used to support the diagnosis of myocardial muscle injury such as MI (myocardial infarction); can also indicate neurologic or skeletal muscle disease

found mostly in skeletal muscles

CK-MM

found mostly in the heart muscle

CK-MB

found mostly in brain tissue

CK-BB

Troponin

Cardiac lab test performed on patients with chest pain to determine if it is due to cardiac ischema. Specific indicator of cardiac muscle injury

Myoglobin

Cardiac lab test used in early evaluation of patients with suspected MI; assists in diagnosis of disease or injury to skeletal muscles

Lipid panel

Cardiac lab test showing total cholesterol

Low-Density Lipoprotein Cholesterol (LDL-C)

The 'bad cholesterol'

High-Density Lipoprotein Cholesterol (HDL-C)

The 'good cholesterol' that protects against vascular disease

Triglycerides

The most common form of circulating body fat; predictors of heart & vascular disease & monitoring of therapy

high

Is high or low HDL good?

low

Is high or low LDL good?

• amylase

• lipase

What are pancreatic function lab tests?

Amylase

Used to detect and monitor the course of acute pancreatitis; usually ordered when the client presents with acute abdominal pain

Lipase

elevated in acute pancreatitis; may be elevated in renal failure

• gloves

• butterfly/needle

• transfer/collection device

• specimen containers

• tourniquet

• antiseptic swabs

• gauze, tape, tube labels

• biohazard bag

• requisition form or bar code

equipment needed for blood samples 9

• sterile equipment & aseptic technique used

• use gloves

• ongoing bleeding for people with bleeding disorders/on blood thinners (coumadin)

What are important risks of taking blood samples? 3

1. yellow

2. light blue

3. red

4. gold/tiger

5. light green

6. green

7. purple

8. pink

9. gray

What is the order of draw? 9

• color

• protein

• ketones

• bilirubin

• specific gravity (concentration)

• osmolality

• pH

• RBCs

• WBCs

What information can you find in a urinalysis? 9

• random

• mid-stream/clean catch

• 24-hour specimen

• catheter

What are the types of urinalysis collections/specimens? 4

24-Hour Urine Collection

A timed urine study requiring the client to discard the initial morning void, record the start time, collect all subsequent urine on ice or refrigeration for $24\text{ hours}$, and void one final time at the 24-hour mark into the container.

Mid-Stream / Clean Catch Collection

A sterile urine sampling method where the patient cleans the urethral meatus using three antiseptic wipes, initiates urination into the toilet, and moves the sterile cup into the stream to obtain a specimen.

amber yellow and aromatic

What is the normal color and odor found in urinalysis?

low indicates dilute urine and excessive diuresis.

high indicates dehydration

What does a low and high specific gravity in urine indicate?

• clostridial toxin assay (C. diff)

• occult blood (Guaiac)

• Stool culture, ova cysts, parasites

What are the types of stool specimens/cultures? 3

• gram stain

• culture and sensitivity

• cytology

What are the types of sputum culture? 3

• use a sterile container for collection

• hold antibiotics until sample is collected

• best time is early morning

• instruct pt to rinse mouth before collecting

• sputum must be coughed up from lungs

What is important to remember with Sputum Culture Collection? 5

Blood Culture Collection Protocol

A sterile two-nurse procedure requiring chlorhexidine skin cleansing for $30\text{ seconds}$ followed by $30\text{ seconds}$ drying, collecting at least $10\text{ mL}$ of blood into aerobic and anaerobic bottles prior to starting antibiotics.

Susceptible (S)

An antibiotic sensitivity interpretation indicating that the bacterial organism cannot grow in the presence of the medication, confirming the drug is effective.

Resistant (R)

An antibiotic sensitivity interpretation indicating that bacteria continue to multiply despite the presence of the drug, confirming the antibiotic is ineffective.

Intermediate (I)

A sensitivity report finding indicating that a higher dosage or concentration of the antibiotic is required to effectively suppress bacterial growth.

Minimum Inhibitory Concentration (MIC)

The lowest concentration of an antibiotic that visibly inhibits the in vitro growth of a specific bacterial pathogen.

Peak Drug Level

The highest concentration of a drug in the bloodstream; measured $15\text{--}30\text{ minutes}$ post-IV infusion, $30\text{--}60\text{ minutes}$ post-IM, or approximately $60\text{ minutes}$ post-oral administration to ensure therapeutic efficacy without toxicity.