Lecture 1 Flashcards
What do electrolytes help with
Homeostasis
* pH Regulation
* Cellular Function
What some conditions that affect electrolytes
and how you make clinical decisions with them
- Dehydration
- Kidney Disease
- Diabetes Mellitus
- Heart Failure
- Add-on Tests
- Guided Diagnosis
What does sodium help with
clinical importance
examples of how they help with regulation
regulates fluid balance, blood pressure, and nerve function
Hyponatremia and Hypernatremia.
Hormonal Mechanisms: Aldosterone increases sodium reabsorption in the kidneys.
Diseased States: adrenal insufficiency or hyperaldosteronism can
disrupt sodium balance.
136-145 mmol/L
What does potassium help with
clinical importance
examples of how they help with regulation
3.5-5.1 mmol/L
-maintains cellular membrane potential, especially in cardiac and skeletal muscles.
Hypokalemia )GI loss -vomiting and diarrhea, Renal loss - increase K excretion, Insulin therapy increase of K update )
and Hyperkalemia (renal failure, diabetes mellitus , trauma from massive hemolysis. Common cause is therapeutic adminstration
Hormonal Mechanisms: Aldosterone promotes potassium excretion in the kidneys.
Diseased States: Renal dysfunction or hyperaldosteronism can cause imbalances.
CALL CRITIALS
What does cholrine
help with
clinical importance
examples of how they help with regulation
98-107 mmol/L
maintaining osmotic pressure and acid-base balance
Hypochloremia and Hyperchloremia
Hormonal Mechanisms: Chloride balance is closely linked with sodium and bicarbonate levels.
Diseased States: Conditions like metabolic acidosis or alkalosis can affect chloride levels.
What does bicarb help with
clinical importance
examples of how they help with regulation
21-28 mmol/L
maintains blood pH
Ordered at CO2 test
Metabolic Acidosis and Metabolic Alkalosis.
Hormonal Mechanisms: The kidneys regulate bicarbonate reabsorption and excretion.
Diseased States: Renal failure or respiratory disorders can disrupt bicarbonate levels.
Specimen Type - Whole Blood - dis/advantages
directly from a sample of whole blood from anticoagulant tube / syringe
Advantages:
No Need for Separation
Faster Turnaround
Disadvantages:
Cellular Influence
Dilution Effect
Specimen Type - Serum
dis/advantages
from serum after blood clotting and centrifugation from non-coagulated tube
Advantages:
Reduced Cellular Effect
Consistency
Disadvantages:
Additional Steps
Potential for Gel Interference
Specimen Type - Plasma
dis/advantages
Measuring electrolytes from plasma obtained by anticoagulated blood (heparin) and centrifuged to separate plasma from cells
Advantages:
Reduced Cellular Influence
Disadvantages:
Dilution Effect
Ensuring Testing Reliability at each stage of processing
Pre-analytical Considerations:
Sample Handling
Sample Preparation
Analytical Considerations:
Calibration
Quality Control
Post-analytical Considerations:
Data Review
Error Management
examples of QC internal and external
Internal QC:
Purpose: Monitors daily performance of testing systems.
Methods: Use of control samples with known values to verify accuracy.
External QC:
Participation: proficiency testing programs to compare results with other labs.
Examples:
Proficiency Testing
Inter-Laboratory Comparisons
External Quality Assessment Schemes
What is an anion gap
difference between the measured cations (sodium)
and the sum of the measured anions (chloride and bicarbonate).
[Na⁺] - ([Cl⁻] + [HCO₃⁻])
Clinical Importance:
* Diagnosis of Metabolic Acidosis
* Guiding Treatment
Clinical Use of Anion Gap
Importance:
o Diagnosis
o Clinical Relevance
Common Conditions
Associated Metabolic Acidosis:
o Diabetic Ketoacidosis (DKA)
o Chronic Kidney Disease (CKD)
o Lactic Acidosis
Delta Checks
comparing current test results with old ones from the patients to see if there are significant changes
Importance:
o Quality Assurance
o Patient Safety
Error Management: Pre-Analytical Errors
errors before the actual analysis phase
Examples:
o IV Fluid Contamination
o Incorrect Tube Collection
o Hemolysis
Impact on Patient Care:
o Incorrect Diagnosis
o Delayed Results
Error Management: Analytical Errors
errors during testing
Examples:
o Instrument Calibration Issues
o Interference
Impact on Patient Care:
o Result Inaccuracy
o Increased Costs
Error Management: Post-Analytical Errors
errors after the analysis phase.
Examples:
o Data Entry Errors
o Reporting Issues
Impact on Patient Care:
o Delayed Intervention
o Patient Safety Risks
What is a Calibration Review
Setting and verifying the accuracy of test instruments.
Procedure: Using calibration standards to adjust instrument settings.
Reviewing Calibration Results:
o Assess Performance
o Adjust if Necessary
Calibration Frequency when it is preformed
regularly based on vendors specs
Unscheduled Situations:
o Analyte Troubleshooting
o Major Maintenance
o Onboard reagent lot expiration
Calibration Drifts and Impacts
gradual changes in the instrument performance over time
Causes:
* Wear and Tear
* Environmental Changes
Impact on Patient Results:
* Inaccurate Test Results
* Quality Assurance Measures
What are critical values and what is the procedure after they arise
results way outside the normal range
Procedure:
o Immediate Notification
o Verification
o Patient Management
Protocols:
o Institutional Policies on reporting
o Communication
Responsibilities of the MLT when it comes to reporting
Accurate Reporting:
* Timeliness
* Critical Results
Patient Care:
* Communication
* Documentation
What is used for Na measurement
and its sources of error
Ion selective electrodes ISE
-two electrodes one with constant potential = reference
-the other is selective for what you are testing = NA
-the difference in potential from reference and measuring and the concentration of the ion in solution
Sources of error
-in indirect method a diluted sample is used for measurement. In samples with excess lipids and proteins it displaces the plasma water (takes up more volume).- falsely low
-protein buildup on the membrane
Vitros and AU480 used direct methods
What is the vitros and au480
Vitros Dry slide chemistry -single-use direct ISE potentiometric system
AU480-3 ISE electrodes, one for each of Na, K, Cl and a reference electrode.
How do we measure K
ISE
ancomycin membrane is used to selectively bind to K+
Change in impedance correlated to K+ concentration
KCl is the inner electrolyte solution
