Lab + Diagnostics Exam 1

G.I.G.O.

What concept reminds clinicians that poor input data leads to poor lab interpretation?

Clinical laboratory science

What interdisciplinary science analyzes blood, urine, CSF, tissue, and other human specimens?

Diagnosis

What is the primary purpose of ordering labs in a symptomatic patient?

Monitoring disease progression

What is the purpose of repeating labs over time in a chronic disease?

Health maintenance

What is the purpose of screening lipid panels in asymptomatic adults?

History and physical exam

What are the most important components of clinical decision making before labs?

Invasive test

What type of test involves entering the body with a needle, scope, or device?

Noninvasive test

What type of test does not penetrate the body?

ABG

What lab test is more invasive than a routine blood draw?

Hematology

What laboratory discipline evaluates RBCs, WBCs, and platelets?

Transfusion medicine

What laboratory discipline focuses on blood compatibility and donation screening?

Chemistry

What laboratory discipline analyzes electrolytes and metabolic substances?

Immunology

What laboratory discipline evaluates humoral and cellular immunity?

Microbiology

What laboratory discipline includes bacteriology, virology, mycology, and parasitology?

Qualitative test

What type of test gives an either/or result such as positive or negative?

Quantitative test

What type of test reports an exact numeric value?

Semiquantitative test

What type of test reports degrees of positivity such as 1+ or 2+?

Pregnancy test

What is an example of a qualitative laboratory test?

Potassium level

What is an example of a quantitative laboratory test?

Urine ketones

What is an example of a semiquantitative laboratory test?

Screening test

What type of test is designed for asymptomatic populations?

Diagnostic test

What type of test confirms disease in symptomatic patients?

High sensitivity

What characteristic is most important in a screening test?

High specificity

What characteristic is most important in a diagnostic test?

SNOUT

What mnemonic means a highly sensitive test rules OUT disease?

SPIN

What mnemonic means a highly specific test rules IN disease?

Sensitivity

What describes a test’s ability to identify patients who truly have disease?

Specificity

What describes a test’s ability to identify patients who do not have disease?

False negative

What error decreases sensitivity?

False positive

What error decreases specificity?

Precision

What term describes reproducibility of repeated test results?

Accuracy

What term describes how close a result is to the true value?

Random error

What type of error primarily affects precision?

Systematic error

What type of error primarily affects accuracy?

Reference range

What statistically derived range is considered normal for a laboratory value?

Gaussian distribution

What statistical distribution is assumed for most reference ranges?

Critical (panic) value

What lab result indicates impending morbidity and requires urgent provider notification?

BMP (basic metabolic panel)

What panel includes electrolytes, BUN, creatinine, calcium, glucose, and CO2?

CMP (comprehensive metabolic panel)

What panel includes BMP plus liver function markers and albumin?

Panel/profile test

What term describes a group of related laboratory studies ordered together?

Predictive value

What test property depends on sensitivity, specificity, and disease prevalence?

Positive predictive value

What increases when disease prevalence increases?

Low disease prevalence

What situation increases the likelihood that a positive result is false?

Pre-test probability

What concept describes likelihood of disease before testing?

Pre-test probability near 50%

When are diagnostic tests usually most informative?

100% sensitive and specific test

What represents the ideal but nonexistent diagnostic test?

Patient preparation

What pre-analytic factor commonly affects specimen quality?

Proper specimen labeling

What quality assurance step prevents patient identification errors?

Quality assurance (QA)

What system ensures laboratory reliability and accuracy?

CLIA ‘88

What legislation standardized laboratory quality regulations?

Levey-Jennings charts

What charts are used in laboratory quality control?

Improper specimen handling

What source of error may invalidate otherwise accurate results?

Human error

What source of lab error includes documentation mistakes and misreading values?

Instrument calibration

What laboratory process prevents systematic error?

Random variation

What unavoidable phenomenon contributes to imprecision?

Lab trends

What are often more clinically useful than isolated lab values?

“Treat the patient, not the lab value”

What principle reminds clinicians to correlate results clinically?

Fluid status

What patient factor can alter lab interpretation?

Drugs and diet

What common patient factors may alter laboratory results?

Age and organ function

What patient factors strongly influence laboratory interpretation?

Testing redundancy

What problem occurs when unnecessary repeat labs are ordered?

Cost-effective testing

What principle discourages ordering unnecessary studies?

Follow-up counseling

What post-analytic provider responsibility is important after abnormal results?

Communication

What provider skill is critical throughout all phases of lab testing?

Ethical and legal implications

What provider considerations are important when ordering diagnostic studies?

Patient autonomy

What principle requires involving patients in diagnostic decisions?

Proper storage and transport

What specimen handling factor preserves test validity?

Fasting state

What patient preparation variable commonly affects chemistry tests?

Ordering clinician and collector initials

What specimen labeling information improves traceability and quality control?

True positive

What test result correctly identifies disease presence?

True negative

What test result correctly identifies disease absence?

False positive

What test result incorrectly identifies disease in a healthy patient?

False negative

What test result incorrectly misses disease in an affected patient?

Accuracy plus precision

What combination defines a clinically reliable laboratory test?

High sensitivity screening

Why are screening tests useful in early disease detection?

High specificity diagnostic testing

Why are confirmatory tests preferred after a positive screen?

Kidney biopsy

What is an example of a highly specific diagnostic test?

Pap smear

What test may function as both screening and diagnostic depending on context?

Serum troponin

What laboratory test is highly specific for myocardial injury?

Blood culture

What diagnostic test identifies bloodstream infection?

Urinalysis (UA)

What relatively noninvasive test evaluates urinary abnormalities?

ABG (arterial blood gas)

What invasive test directly measures acid-base and oxygenation status?

POC testing

What type of testing is performed near the patient rather than in a central laboratory?

Basic metabolic panel (BMP)

What common laboratory panel evaluates electrolytes, renal function, glucose, and acid-base balance?

Na, K, Cl, HCO3, BUN, Cr, glucose, Ca

What labs are included in a BMP?

Sodium, potassium, chloride, bicarbonate, BUN, creatinine, glucose, calcium

What are the components of a BMP?

BMP indication

When should a BMP commonly be ordered?

Kidney function assessment, Electrolyte imbalance, Acid-base disorders

What is a major indication for ordering a BMP?

Large amount of information from one venipuncture

What is a major advantage of the BMP?

Sodium

What BMP electrolyte is primarily extracellular?

Hyponatremia

What sodium abnormality is commonly caused by CHF, fluid loss, or water intoxication?

Hypernatremia

What sodium abnormality is most commonly associated with dehydration?

Water intoxication

What condition can cause dilutional hyponatremia?

Cushing disease

What endocrine disorder may cause hypernatremia?

Potassium

What BMP electrolyte is primarily intracellular?

Hypokalemia.

What potassium abnormality commonly results from vomiting or diarrhea?

Hyperkalemia

What potassium abnormality is commonly caused by kidney disease?

Uncontrolled diabetes

What endocrine disorder commonly causes hyperkalemia?

GI losses

What common mechanism causes hypokalemia?

Insulin deficiency

What metabolic problem contributes to hyperkalemia?