Clinical Biochemistry (CHM 2311) Quiz

Clinical Biochemistry (CHM 2311) Fall 2024

• Course for BSCN program
• Focuses on clinical biochemistry and interpretation of results

Defining Terms

• Health vs. Disease: Distinction between healthy states and disease states
• Impact of Cultural Factors: How culture influences health and disease
• Normal vs. Abnormal: Defining and differentiating normal and abnormal physiological states
• Physiological Factors: Factors like sex, age, timing, posture, and exercise that affect results

Usefulness of Biochemical Tests

• Importance of biochemical tests
• Diagnosis: Combining medical history, physical examination, and biochemical analysis for diagnosis

Clinical Chemistry Departments

• Routine Biochemistry: Standard biochemical tests
• Therapeutic Drug Monitoring (TDM): Monitoring drug levels in patients
• Toxicology: Analyzing toxins and their effects
• Arterial Blood Gases (ABG): Analyzing gases in the blood

Specimen Collection

• Specimen: Correct technique for collecting specimens
• Client Identification: Proper identification of the patient
• Analyses Required: Tests specified for the analysis.
• Reason for Analyses: Justification for the tests conducted on the sample

Sampling Errors

• Difficulty in Blood Sampling causing Hemolysis: Problems with the blood collection process causing the release of hemoglobin from red blood cells.
• Prolonged Stasis during Venepuncture: Prolonged tourniquet placement
• False variations in several measurable analytes: Differences in patient conditions in measuring the analyte
• Insufficient Specimen Volume: Not enough sample volume for the requested tests
• Errors in timing of collection: Issues related to time of sample collection
• Duration of sample Collection
• Incorrect Specimen container: Improper containers for sample collection
• Innappropriate sampling site.
• "Drip arm" artifacts: issues from the collection site
• Incorrect specimen storage: Improper sample storage

Biochemical Results Expression

• Quantitative Analyses: Most biochemical analyses are numerical
• Concentration Units: Different units of measurement for concentrations (mmol/L, mg/dL)
• Solute and Solvent Concentration: Concentration is the amount of solute in a given amount of solvent.

Reference Intervals

• Comparison of results with reference range to identify normal variations
• Calculation of reference interval for particular tests: Each hospital/laboratory calculates appropriate reference ranges
• Reference ranges: chosen arbitrarily to include 95% of values found in the population.
• Reference Intervals as guidelines: Reference intervals are used merely as guidelines.

False-Positive and False-Negative Results

• Diagnostic cut-off: Separating healthy from diseased populations
• Sensitivity and Specificity: Measuring the reliability of tests by these metrics
• Sensitivity: frequency which tests correctly identify patients with the disease
• Specificity: How often healthy subjects are identified
• Accuracy: closeness of measured values to "true" values
• Precision: Reproducibility of a method

Health Care Providers and Lab Test Requests

• Importance of medical history, physical examination, and objective test results, selecting tests
• Sensitive or specific tests as priority selection

Variation of Biochemical Test Results - Patient Monitoring

• Reasons to request further biochemical tests
• Repeated biochemical tests, identical results
• Markedly different biochemical test results
• Preanalytical variation in patient sample collection
• Analytical variation during the testing process
• Intrinsic or biological variation between patients

### 10.1 Preanalytical Variation

• Time of Day: Influence on test results
• Posture: Impact on biochemical test results.
• Fasting Status: Effects of fasting on biochemical tests
• Time in Transit to Laboratory: Time between sample collection and test processing.

### 10.2 Analytical Variation

• Temperature: Fluctuations affecting test results
• Pipetted reagent/sample volume: Accuracy in volume dispensing influencing test results.
• Repeated Analysis: Not feasible to analyse every sample repeatedly due to volume
• Internal Quality Control (IQC): Use of control samples to maintain test accuracy

10.3 Intrinsic Biological Variation

• "Within-subject variation": Fluctuations in same individual due to hormonal variations
• Homestatic set point fluctuation: Homeostatic set points fluctuate randomly.
• Samples from the same individual: Variation of biochemical test results within the same individual.

11. Analytical Aspects of Biochemical Tests

• Reliability of Biochemical Results
• Precision: Methodology reproducibility
• Accuracy: Closeness to "true value" of test results
• Quality Assurance: verification and testing process

12. Point-of-Care Testing

• Blood tests
• Urine tests
• Advantages of point-of-care results (cost, responsibility)

13. Routine Urinalysis

• Screening Tool for Renal/Metabolic Diseases: Detection of renal and metabolic disorders through urine tests.
• Glucose, Bilirubin, Urobilinogen: Detection of these substances in urine
• Ketones, Specific Gravity, pH: Indicators for various conditions
• Proteins, Blood, Leukocyte Esterase, Nitrite: Assessment involving these substances in urine

14. Fecal Analysis

• Diagnostic tool for digestive tract disorders: Detection of digestive tract disorders through samples
• Macroscopic, Microscopic and Chemical Examinations: Evaluation of fecal components
• Investigations of gastrointestinal disorders (e.g., fat test, calprotectin, pancreatic elastase, trypsin, FIT)

15. Blood Testing

• Electrolyte abnormalities, Specific markers of disease
• Enzymes, Proteins, Tumour markers

15.1 Enzymes

• Biological Catalysts
• 3-D structure, specific substrates
• Cell enzyme varieties
• Tissue enzyme generation upon stimuli
• Isoenzymes

15.2 Clinically Relevant Enzymes

• Tissue/organ damage markers
• Intracellular enzyme use
• Location in small number of tissues

15.3 Clinically Relevant Enzymes (Specific)

• Alanine aminotransferase (ALT)
• Amylase and lipase
• Creatine kinase (CK)
• Alkaline phosphatase (ALP)
• Gamma-glutamyl transpeptidase (GGT)
• Aspartate aminotransferase (AST)
• Lactate dehydrogenase (LDH)

15.3.1 Aminotransferases and Liver Disease

• Clinically relevant aminotransferases (ALT, AST)
• Locations in the body (liver, kidney, etc.)
• Clinical significance and Liver disease
• Hepatic destruction

15.3.2 Enzymes in acute pancreatitis

• Amylase and Lipase
• Locations and clinical significance

15.3.4 Enzymes in muscular damage

• Creatine kinase (CK)
• Clinical significance (tissue pathologies

15.3.5 Enzymes in liver and bone diseases

• Alkaline phosphatase (ALP)
• Location and clinical significance

15.3.6 Enzymes in hepatobiliary disease

• Gamma-glutamyl transpeptidase (GGT)
• Location and clinical significance

15.3.7 Enzymes in anemia and cancer

• Lactate dehydrogenase (LDH)
• Clinical significance and usefulness

Test your knowledge on clinical biochemistry concepts, focusing on the distinctions between health and disease, the impact of cultural factors on health, and the significance of biochemical tests in diagnosis. This quiz will cover various aspects of routine biochemistry, drug monitoring, and specimen collection techniques crucial for BSCN students.