Chemistry and Blood Bank Overview

These flashcards cover key terms and definitions related to chemistry and blood bank protocols, important for clinical diagnostics and laboratory practices.

CK-MB

A cardiac marker more specific than total CK, rises earlier than troponin, and indicates cardiac muscle damage.

ECLIA

Electrochemiluminescence; a method for measuring light emission from an antigen-antibody reaction.

Quality Assurance (QA)

A systematic set of processes to ensure lab results are accurate and reliable before reporting.

Calibration

The process of checking and adjusting the instruments to ensure accuracy, performed when QC fails or reagent lots change.

Proficiency Testing

Testing conducted to evaluate the laboratory's accuracy and reliability by comparing results with accepted standards.

Cold Antibodies

Antibodies that react at lower temperatures, potentially causing discrepancies in blood typing results.

Elution

A procedure performed to remove antibodies from RBCs for identification, typically conducted after a positive DAT result.

Interpretation of Laboratory Results

The process of analyzing patterns and trends in lab data to diagnose conditions, such as infections or anemia.

Differential Diagnosis

The process of distinguishing a disease or condition from others that present similar clinical features.

Internal QC

Quality control measures taken within a laboratory, such as running daily controls to monitor instrument accuracy.

CK-MB

A cardiac marker more specific than total CK, rises earlier than troponin, and indicates cardiac muscle damage.

Troponin

A highly specific cardiac protein (I or T) and the gold standard marker for myocardial infarction; it stays elevated for 10-14 days.

Myoglobin

An early marker of muscle injury that rises within 1-3 hours of damage; it is sensitive but lacks cardiac specificity.

ECLIA

Electrochemiluminescence; a method for measuring light emission from an antigen-antibody reaction.

Quality Assurance (QA)

A systematic set of processes to ensure lab results are accurate and reliable before reporting.

Calibration

The process of checking and adjusting instruments to ensure accuracy, performed when QC fails or reagent lots change.

Proficiency Testing

Testing conducted to evaluate the laboratory's accuracy and reliability by comparing results with external accepted standards.

Cold Antibodies

Antibodies that react at lower temperatures, potentially causing discrepancies in blood typing results.

Elution

A procedure performed to remove antibodies from RBCs for identification, typically conducted after a positive DAT result.

Direct Antiglobulin Test (DAT)

A test used to detect antibodies or complement components already bound to red blood cells in vivo.

Indirect Antiglobulin Test (IAT)

A test used to detect unbound red cell antibodies in serum or plasma in vitro, used for screening and crossmatching.

Interpretation of Laboratory Results

The process of analyzing patterns and trends in lab data to diagnose conditions, such as infections or anemia.

Differential Diagnosis

The process of distinguishing a disease or condition from others that present similar clinical features.

Internal QC

Quality control measures taken within a laboratory, such as running daily controls to monitor instrument accuracy.

Precision vs Accuracy

Precision is the reproducibility of results (closeness of values to each other), while Accuracy is the closeness of a result to the true value.

Coefficient of Variation (CV)

A measure of relative precision calculated as: CV = (\frac{s}{\bar{x}}) \times 100\%. Lower percentages indicate better precision.

Westgard Rules

A set of statistical rules (e.g., 1{2s}, 2{2s}, 1_{3s}) used to determine if an analytical run is in control or should be rejected.

Hemolysis

The rupture of Red Blood Cells which can cause false elevation in analytes such as Potassium (K^+) and Lactate Dehydrogenase (LDH).

Critical Value

A laboratory result that indicates a life-threatening situation and requires immediate notification to the healthcare provider.

Pre-analytical Phase

The stage of testing including patient ID, specimen collection, and transport; the phase where the majority of laboratory errors occur.

CK-MB

A cardiac marker more specific than total CK that rises earlier than troponin and indicates cardiac muscle damage.

Troponin

A highly specific cardiac protein (I or T) and the gold standard marker for myocardial infarction that stays elevated for 10-14 days.

Myoglobin

An early marker of muscle injury that rises within 1-3 hours of damage; it is sensitive but lacks cardiac specificity.

ECLIA

Electrochemiluminescence; a method used in clinical laboratories to measure light emission generated by antigen-antibody reactions.

Quality Assurance (QA)

A systematic set of processes designed to ensure that laboratory results are accurate, reliable, and reproducible before they are reported.

Calibration

The process of checking and adjusting laboratory instruments to ensure measurement accuracy, performed when QC fails or reagent lots change.

Proficiency Testing

A quality assessment tool where a laboratory evaluates its accuracy by comparing results for external samples with accepted standards.

Cold Antibodies

Antibodies that react at lower temperatures, often causing discrepancies or interference in blood bank testing and blood typing.

Elution

A laboratory procedure used to remove antibodies from the surface of red blood cells for identification, often following a positive DAT result.

Direct Antiglobulin Test (DAT)

A test used to detect IgG or complement components that are already bound to red blood cells in vivo.

Indirect Antiglobulin Test (IAT)

A test used to detect unbound red cell antibodies in serum or plasma in vitro, commonly used for antibody screening and crossmatching.

Internal QC

Quality control measures conducted within a laboratory, such as running daily control samples to monitor the stability of analytical instruments.

Precision vs Accuracy

Precision is the reproducibility of results (closeness of values to each other), while accuracy is the closeness of a result to the true value.

Coefficient of Variation (CV)

A measure of relative precision calculated as: CV = (\frac{s}{\bar{x}}) \times 100\%. Lower percentages indicate better precision.

Westgard Rules

A set of statistical rules used to determine if an analytical run is in control or should be rejected based on quality control data.

Hemolysis

The rupture of red blood cells during collection or processing, which can falsey elevate analytes like Potassium (K^+) and LDH.

Critical Value

A laboratory result that represents a life-threatening situation for a patient and requires immediate notification to a healthcare provider.

Pre-analytical Phase

The phase of testing involving patient identification, specimen collection, and transport; the stage where most laboratory errors occur.

Analytical Phase

The stage of laboratory testing that involves the actual analysis or physical measurement of the analyte in the specimen.

Post-analytical Phase

The stage of lab testing including the calculation of results, verification, reporting, and the clinical interpretation by the provider.

Random Error

An inconsistent error that affects precision, caused by unpredictable factors like bubbles in reagents or temperature fluctuations.

Systematic Error

A consistent bias in testing results that affects accuracy, often caused by deteriorating reagents, poor calibration, or failing light sources.

Shift

A sudden change in QC data where values remain on one side of the mean, often indicating a new reagent lot or instrument maintenance.

Trend

A gradual change in QC values over time, usually indicating reagent degradation or the slow failure of an instrument component.

Sensitivity

The ability of a test to correctly identify patients who have a specific disease (true positive rate).

Specificity

The ability of a test to correctly identify patients who do not have a specific disease (true negative rate).

BNP (Brain Natriuretic Peptide)

A cardiac marker used to diagnose and monitor congestive heart failure (CHF) and fluid overload states.

Delta Check

A quality control method comparing a patient's current laboratory result with their previous result to detect specimen or patient identification errors.

Standard Deviation (s)

A statistical measure of the dispersion or spread of a set of data points from their mean (\bar{x}).

Reference Interval

The range of test values established as 'normal' based on a healthy population, used to interpret patient results.

Levey-Jennings Chart

A graphical representation used to plot quality control data to visually identify trends, shifts, or random errors within analytical runs.

Differential Diagnosis

The process of distinguishing a specific disease or condition from others that present with similar clinical features.