(P) Lec 1: Electrolytes Flashcards
Electrolytes are:
1. (Organic/Inorganic) substances
2. Capable of (dissociating/ionizing) into ions
3. Compounds that (contain/do not contain) carbon
4. Able to form their own charges in (pure/ultrapure) water
- Inorganic
- Dissociating
- Contain
- Pure
What are the positive (+) and negative (-) charges called?
Cations (+) and Anions (-)
Enumerate the 5 medically important electrolytes in the body
- Sodium (Na+)
- Chloride (Cl-)
- Potassium (K+)
- Calcium (Ca 2+)
- Magnesium (Mg 2+)
Which among the 5 medically important electrolytes in the body is the sole anion?
Chloride (review its placement in the periodic table; on the right)
Functions of Electrolytes
- Controls the ________ of water between fluid compartments
- Maintains the ___-___ balance
- Production of ________ potential
- ________ for enzymes
- Maintenance of electrical ________
- Osmosis
- Acid-base
- Action
- Cofactors
- Neutrality
What are the 2 body fluid compartments?
Extracellular and Intracellular
The Extracellular and Intracellular compartments are mainly maintained by what 2 electrolytes?
Sodium (Na) and Chloride (Cl)
What 2 electrolytes are involved in “chloride shifting” during acid-base balancing of the electrolytes?
Potassium (K+) and Chloride (Cl-)
TOF: The body system is dependent on pOH
False (pH)
What 2 electrolytes are needed for the production of muscle action potentials?
Potassium (K+) and Calcium (Ca 2+)
This electrolyte plays an important role as a cofactor for enzymes; it works alongside zinc in trace elements and porphyrins
Magnesium (Mg 2+)
This body fluid has electrical neutrality (anions = cations)
Note: if too much, it would be released and if too little, it would be produced
Blood
Which 2 electrolytes have a 2+ charge?
Magnesium (Mg 2+) and Calcium (Ca 2+)
Identify the function from the given electrolyte/s
Sodium (Na+) and Chloride (Cl-)
Osmosis of water
Identify the function from the given electrolyte/s
Potassium (K+) and Chloride (Cl-)
Acid-base balance
Identify the function from the given electrolyte/s
Potassium (K+) and Calcium (Ca 2+)
Production of action potential
Identify the function from the given electrolyte/s
Magnesium (2+) with Zinc
Enzyme cofactor
Refers to the difference between the cations and anions routinely measured in serum
Anion Gap
What 4 electrolytes are used in computing for the anion gap?
- Sodium (Na+)
- Potassium (K+)
- Chloride (Cl-)
- Bicarbonate (HCO3-)
Familiarize yourself with the 2 anion gap formulae
- [Na + K] - [Cl + HCO3]
- [Na] - [Cl + HCO3]
Note: The difference is between the absence and presence of K+
What is the normal value for the anion gap (in mmol/L)?
10 to 17 mmol/L
The anion gap (anions = cations) is significant for what?
Electrical neutrality
Increased or Decreased Anion Gap Result?
Uremia, ketosis, lactic acidosis, dehydration, ingestion of toxins, salicylates, and paraldehyde
Increased
Increased or Decreased Anion Gap Result?
Lithium toxicity, hypermagnesemia, multiple myeloma, polyclonal gammopathy, polymyxin B treatment, and hypoalbuminemia
Decreased
TOF: If the electrolyte result of an individual is abnormal but the anion gap is normal, the machine may have a problem
False (electrolyte is normal but anion gap is abnormal)
Once an individual accumulates an acidic anion, it may actually (increase/decrease) the anion gap
Increase
If the accumulated electrolytes are proteins with basic properties, it will (increase/decrease) the anion gap
Decrease
Electrolyte Exclusion
The electrolyte exclusion effect is performed in what measurement of serum or plasma?
Water Phase Measurement
Electrolyte Exclusion
For blood chemistry analysis, the blood should be (clotted/in liquid form) before centrifuging
Clotted
Electrolyte Exclusion
What 3 layers are formed after centrifuging a blood sample?
- Plasma/serum
- Buffy coat
- Packed RBCs
Electrolyte Exclusion
What aliquot is obtained and used from the centrifuged tube for this procedure?
Plasma/serum (the liquid portion)
Electrolyte Exclusion
How much (in percentage) does the plasma/serum make up the blood sample in the tube?
60%
Electrolyte Exclusion
How much (in percent) of the plasma/serum is water?
Note: The water is what will be measured
98%
- The most abundant EXTRACELLULAR CATION and electrolyte in general
- Has an intracellular to extracellular ratio of 1:12
- Functions as the principal osmotic pressure maintainer
Sodium (Na+)
What is the old name of Sodium?
Natrium
Sodium Regulation
- This hormone is for water retention/absorption
- If water is retained, sodium is also retained because sodium follows where water goes
- Therefore, it increases sodium in the system as well
Antidiuretic Hormone (ADH)
Sodium Regulation
- This is for the reabsorption of sodium in the DCT of the kidney
- It increases sodium value
Aldosterone
Sodium Regulation
- A marker for congestive heart failure (CHF)
- It is produced by the heart to promote natriuresis (sodium is excreted out of urine)
- Therefore it decreases sodium levels
Atrial Natriuretic Peptide (ANP)
Sodium Regulation
Which among ADH, Aldosterone, and ANP increases sodium in the system?
ADH and Aldosterone
Sodium Regulation
Which among ADH, Aldosterone, and ANP decreases sodium in the system?
ANP only
Sodium Regulation
Aldosterone is responsible for the reabsorption of sodium in what part of the kidney?
DCT
Hyponatremia or Hypernatremia?
Overhydration, diuretic therapy, metabolic acidosis, Addison’s disease, and diarrhea
Hyponatremia
Hyponatremia or Hypernatremia?
Dehydration, Cushing’s syndrome, insulin therapy, profuse sweating, diarrhea, and diabetes insipidus
Hypernatremia
This is caused by sodium loss or high water intake
Hyponatremia
This is caused by low water intake/dehydration/ water depletions or too much intake of sodium
Hypernatremia
Sodium Measurement
What specimen is ideally used?
Serum (plasma can be used but for emergency cases only)
Sodium Measurement
If plasma is to be used in emergency cases, what anticoagulant must be used?
Heparin
Note: Avoid a tube that uses sodium salt as it will increase sodium
Sodium Measurement
TOF: A hemolyzed sample will increase sodium levels
False (decrease; pseudohyponatremia)
Sodium Measurement
Hemolysis and too much lipids and plasma proteins causes what condition?
Pseudohyponatremia
Sodium Measurement
- This method selectively measures a specific ion
- Uses a glass membrane electrode
- May be direct or indirect
Ion Selective Electrode (ISE)
Sodium Measurement
The Ion Selective Electrode (ISE) for sodium uses what kind of electrode?
Glass Membrane Electrode
Sodium Measurement
In the Ion Selective Electrode (ISE) method, what technique requires no dilution (no pseudohyponatremia)?
Direct
Sodium Measurement
In the Ion Selective Electrode (ISE) method, what technique requires dilution (pseudohyponatremia is possible)?
Indirect
Sodium Measurement
- This is a spectrophotometric method that uses flames as a light source
- The sample, upon contact with the flame will produce its own color
Flame Emission Spectrophotometry (FES)
Sodium Measurement
In Flame Emission Spectrophotometry (FES), what flame color does sodium produce?
Yellow
Sodium Measurement
In this method, sodium forms a complex with the reagent to form sodium uranyl acetate
Colorimetric/Spectrophotometric
Sodium Measurement
What method in the Colorimetric/Spectrophotometric technique uses Zinc Uranyl Acetate?
Albanese-Lein Method
Sodium Measurement
What method in the Colorimetric/Spectrophotometric technique uses Magnesium Uranyl Acetate?
Maruna Trinder
Sodium Measurement
In both the Albanese-Lein Method and Maruna Trinder Method, sodium forms a complex with the reagent to produce what?
Sodium Uranyl Acetate
Sodium Measurement
This is the reference method wherein electrolytes are measured in their atomic forms
Atomic Absorption Spectrophotometry (AAS)
- The most abundant INTRACELLULAR CATION important for maintaining the acid-base balance of the body
- It is the most clinically significant and sensitive in terms of increasing value as it can lead to cardiac failure
Potassium (K+)
TOF: Potassium increases whenever there is cell lysis
True (because it is found INSIDE the cell; an intracellular electrolyte)
- It has an intracellular to extracellular ratio of 25:1
- It helps in nerve impulse transmission, action potential production, and is a major ion affecting cardiac cells
- If imbalanced, it could lead to motor imbalances and skeletal/cardiac problems
Potassium (K+)
- This hormone regulates potassium by excretion as it also promotes sodium reabsorption
- When sodium gets reabsorbed, potassium gets excreted
Aldosterone
Hypokalemia or Hyperkalemia
Alkalosis and Insulin Therapy
Hypokalemia
Hypokalemia or Hyperkalemia
Acidosis, cell damage, and mineralocorticoid deficiency
Hyperkalemia
TOF: The increasing and decreasing value of potassium levels are caused by the shifting in position from extracellular going to intracellular
False (from intracellular going to extracellular)
Hypokalemia or Hyperkalemia
From the serum, it will enter the RBC
Hypokalemia
Hypokalemia or Hyperkalemia
From the RBC, it goes to the plasma
Hyperkalemia
- This is aka pseudohyperkalemia, the false increase of potassium
- The most collection-sensitive analyte
Artifactual Hyperkalemia
What is the number 1 reason for pseudohyperkalemia?
Collection (leads to hemolysis)
Which among the ff. is not a cause for pseudohyperkalemia?
- Hemolysis
- Low platelet count
- Delayed separation
- Refrigeration
Low platelet count (should be high)
Potassium Measurement
This uses a liquid ion exchange membrane incorporated with valinomycin
Ion Selective Electrode (ISE)
Potassium Measurement
What color of flame does potassium emit using the Flame Emission Spectrophotometry (FES) Method?
Purple/Lilac
Potassium Measurement
This method consists of Turbidimetric and Lockhead and Purcell sub-methods
Colorimetric/Spectrophotometric
Potassium Measurement
- In the colorimetric/spectrophotometric method, this sub-method uses sodium tetraphenyl boron
- A positive result is the precipitation of potassium
Turbidimetric
Potassium Measurement
In the turbidimetric method, what is the positive result after using sodium tetraphenyl boron?
Precipitation of potassium
Potassium Measurement
In the turbidimetric method, what is the main component of the reagent?
Sodium tetraphenyl boron
Potassium Measurement
- In the colorimetric/spectrophotometric method, this sub-method uses sodium cobaltinitrite
- A positive result is color red in the presence of potassium
Lockhead and Purcell
Potassium Measurement
In the Lockhead and Purcell method, what is the positive result after using sodium cobaltinitrite?
Color red (in the presence of K+)
Potassium Measurement
In the Lockhead and Purcell method, what is the main component of the reagent?
Sodium cobaltinitrite
Potassium Measurement
What is the reference method?
Atomic Absorption Spectrophotometry (AAS)
- This is the most abundant EXTRACELLULAR ANION
- It regulates osmotic pressure and water balance alongside sodium
- Wherever sodium goes, water follows along with this electrolyte
Chloride (Cl-)
- An important function of chloride in maintaining the acid-base balance in RBCs
- The RBC exchanges some of its hydrogen ions
Chloride Shifting
Hypochloremia or Hyperchloremia?
Metabolic alkalosis and respiratory acidosis
Hypochloremia
Hypochloremia or Hyperchloremia?
Metabolic acidosis and respiratory alkalosis
Hyperchloremia
Chloride Measurement
- This uses the principle of Schales and Schales
- An old colorimetric method where mercury reacts with chloride to form mercuric chloride
- It is then titrated using diphenyl carbazon forming a blue-colored compound upon measurement
Mercumetric Titration
Chloride Measurement
In Mercumetric Titration, what principle does it use?
Schales and Schales
Chloride Measurement
In Mercumetric Titration, mercuric chloride is titrated using what?
Diphenyl Carbazon
Chloride Measurement
In Mercumetric Titration, what is the end product’s color?
Blue
Chloride Measurement
What are the 2 techniques involved in the mercuric thiocyanate method?
- Skegg’s modification
- Whitehorn titration technique
Chloride Measurement
In the Mercuric Thiocyanate method:
- This technique allows mercuric thiocyanate to react with chloride forming mercuric chloride and thiocyanate (they separate)
- It is then treated with a ferric ion to produce ferric thiocyanate
- The end color is reddish-brown
Skegg’s Modification
Chloride Measurement
In Skegg’s Modification of the Mercuric Thiocyanate Method, mercuric thiocyanate + chloride forms what?
Mercuric chloride and thiocyanate
Chloride Measurement
In Skegg’s Modification of the Mercuric Thiocyanate Method, mercuric chloride and thiocyanate + ferric ion forms what?
Ferric Thiocyanate
Chloride Measurement
In Skegg’s Modification of the Mercuric Thiocyanate Method, what is the color of the end product (ferric thiocyanate)?
Reddish brown
Chloride Measurement
In the mercuric thiocyanate method, this is considered as the old methodology for measuring colorimetric methods
Whitehorn Titration Technique
Chloride Measurement
This is the reference method
Colorimetric-Amperometric Titration
Chloride Measurement
This technique in the colorimetric-amperometric titration method uses electrodes with silver ions which react with chloride to form a silver chloride precipitate
Cotlove Technique
Chloride Measurement
- This technique uses collected sweat using the Gilbson and Cooke principle
- It is collected through pilocarpine iontophoresis which uses pilocarpine nitrate
Sweat Chloride Determination
Chloride Measurement
In Sweat Chloride Determination, what principle is used?
Gilbson and Cooke
Chloride Measurement
In Sweat Chloride Determination, how is the sample collected?
Pilocarpine iontophoresis
Chloride Measurement
In Sweat Chloride Determination, what chemical is used?
Pilocarpine nitrate
- This is the 5th most abundant mineral in the body
- Majority of it is present in the skeletal system
- Functions in blood coagulation, neuromuscular conduction, and cardiac and skeletal muscle excitability
Calcium (Ca 2+)
Majority of calcium is present in the skeletal system in the form of what?
Hydroxyapatite crystals
How much (in percentage) of hydroxyapatite crystals are in bones and how much are in plasma?
98% in bones and 2% in plasma
The 2% of ________ in plasma are composed of ionized calcium, protein-bound calcium, and anion-bound calcium
Hydroxyapatite crystals
Give the percentages of the ff. components of the 2% hydroxyapatite crystals found in plasma
- Ionized/free calcium
- Protein-bound
- Anion-bound
- Ionized/free calcium (50%)
- Protein-bound (40%)
- Anion-bound (10%)
This is regulated by PTH, vitamin D, and calcitonin
Calcium (2+)
Calcium
PTH, Vitamin D, or Calcitonin?
A hypercalcemic agent which allows calcium to be reabsorbed in the kidneys and bones
PTH
Calcium
PTH, Vitamin D, or Calcitonin?
A hypercalcemic agent that directly increases calcium in blood
Vitamin D
Calcium
PTH, Vitamin D, or Calcitonin?
A hypocalcemic agent
Calcitonin
Calcium
PTH, Vitamin D, or Calcitonin?
Which are hypercalcemic and which are hypocalcemic?
- Hypercalcemic: PTH and Vit. D
- Hypocalcemic: Calcitonin
Calcium
TOF: Vitamin D promotes PTH synthesis to increase calcium levels
False (reverse; it is PTH that promotes the synthesis of Vit. D)
Hypocalcemia or Hypercalcemia?
Hypoparathyroidism, steatorrhea, renal diseases, and pancreatitis
Hypocalcemia
Hypocalcemia or Hypercalcemia?
Hyperparathyroidism, multiple myeloma, tuberculosis, and antacids
Hypercalcemia
Calcium Measurement
Pre-ionized calcium + protein-bound calcium + anion-bound calcium = ?
Total Calcium
Calcium Measurement (TOTAL CALCIUM)
In this colorimetric method:
- Calcium is treated with ammonium oxalate to form calcium oxalate
- Then an acid is added to dissolve the crystals to form oxalic acid
- Oxalic acid is titrated with potassium permanganate producing a purple to colorless reaction
Clark and Collip
Calcium Measurement (TOTAL CALCIUM)
In Clark and Collip, calcium + ammonium oxalate = ?
Calcium oxalate
Calcium Measurement (TOTAL CALCIUM)
In Clark and Collip, calcium oxalate + acid = ?
Oxalic Acid
Calcium Measurement (TOTAL CALCIUM)
In Clark and Collip, oxalic acid titrated with potassium permanganate produces what color reaction?
From purple to colorless
Calcium Measurement (TOTAL CALCIUM)
In this method:
- Calcium is mixed with Calcin Red followed by titration with an anticoagulant
- It becomes yellowish with a green fluorescence
- The calcium-calcin complex will be lost and the end product is salmon pink in color
EDTA titration
Calcium Measurement (TOTAL CALCIUM)
In EDTA titration, what is mixed with calcium to form a yellowish product with green fluorescence?
Calcin Red
Calcium Measurement (TOTAL CALCIUM)
In EDTA titration, what is the final end color upon losing the calcium-calcin complex?
Salmon pink
Calcium Measurement (TOTAL CALCIUM)
In this method:
- It is more on dye-binding
- Has 3 sub-methods: O-Cresolphthalein, Alizarin, and Arsenazo III
Spectrophotometric
Calcium Measurement (TOTAL CALCIUM)
In spectrophotometry, this is the most popular and it produces a violet end color
O-Cresolphthalein
Calcium Measurement (TOTAL CALCIUM)
In spectrophotometry, this uses 8-hydroxyquinoline
Alizarin
Calcium Measurement (TOTAL CALCIUM)
This is the reference method
Atomic Absorption Spectrophotometry (AAS)
Calcium Measurement (TOTAL CALCIUM)
What are the 4 methods for total calcium measurement?
- Colorimetric
- EDTA Titration
- Spectrophotometric
- Atomic Absorption Spectrophotometry
Calcium Measurement (IONIZED CALCIUM)
In this method, the pH is maintained in a sample as calcium ionization is pH dependent
Ion Selective Electrode (ISE)
Calcium Measurement (IONIZED CALCIUM)
TOF: A higher pH correlates to lower ionization
True
Calcium Measurement (IONIZED CALCIUM)
TOF: Blood is directly proportional to pH
False (indirect)
- This is found in bones, muscles, and ECF
- It functions in structural support, energy generation, and storage
- It exists in the form of a buffer phosphate
- Is influenced by PTH, Vit. D, and Calcitonin
- Is inversely proportional to calcium
Phosphorus
If PTH and Vit. D increase calcium, what happens to phosphorus?
Decreases
If Calcitonin decreases calcium, what happens to phosphorus?
Increases
Phosphorus Measurement
This is the reference method
Atomic Absorption Spectrophotometry (AAS)
Phosphorus Measurement
In this method:
- It measures the end product phosphomolybdenum blue at 600nm
- It is the most popular method in measuring phosphorus
- The reagent is ammonium molybdate
Spectrophotometric (Fiske and Subbarow)
Phosphorus Measurement
In Fiske and Subbarow, when ammonium molybdate reacts with phosphorus, it produces what?
Phosphomolybdate (colorless)
Phosphorus Measurement
In Fiske and Subbarow, when a reducing agent such as ascorbic acid is added, it becomes what?
Phosphomolybdenum Blue
Phosphorus Measurement
In Fiske and Subbarow, what is the end product?
Phosphomolybdenum Blue
Phosphorus Measurement
In Fiske and Subbarow, phosphomolybdenum blue is measured at what wavelength?
600nm
- Its main function is to be a cofactor
- It is the 2nd most abundant INTRACELLULAR CATION and 4th most abundant cation in the body
Magnesium (Mg 2+)
Magnesium Measurement
This is the reference method
Atomic Absorption Spectrophotometry (AAS)
Magnesium Measurement
What color of flame does magnesium emit when using the Flame Emission Spectrophotometry (FES) method?
Blue
Magnesium Measurement
In spectrophotometry, specifically dye-binding, give the end point colors of the ff. reagents:
- Calmagite
- Formazan dye
- Methylene
- Calmagite - green
- Formazan dye - dark blue
- Methylene - blue
Magnesium Measurement
In this method:
- It is considered as an old colorimetric method
- One of the first methods used for testing magnesium
- Produces a yellow to red dye in the presence of magnesium
Titan Yellow (Colorimetric)
Magnesium Measurement
In the Titan Yellow (Colorimetric) method, what color is produced in the presence of Mg 2+?
Yellow to red dye
- This is a basic substance important for the acid-base balance
- The 2nd most abundant anion in the ECF
Bicarbonate (HCO3-)
Give the 2 methods for measuring bicarbonate (HCO3-)
- Acid Titration and pCO2 Electrode
- Alkalinization and Enzymatic Method
All electrolytes have Atomic Absorption Spectrophotometry (AAS) as their reference method, except for one, what is that electrolyte?
Chloride (Cl-)
Give all the EXTRACELLULAR electrolytes
- Sodium (cation)
- Chloride (anion)
- Phosphorus (neither an anion or cation)
- Bicarbonate (anion)
Give all the INTRACELLULAR CATIONS
- Potassium (K+)
- Calcium (Ca 2+)
- Magnesium (Mg 2+)
Give all the EXTRACELLULAR ANIONS
- Chloride (Cl-)
- Bicarbonate (HCO3-)
TOF: All the anions discussed are intracellular but not all cations discussed are extracellular
False (all anions discussed are extracellular)
What is the only EXTRACELLULAR CATION among all the electrolytes discussed?
Sodium (Na+)
Give the electrolyte correspondent to the given
Has an intracellular to extracellular ratio of 1:12
Sodium (Na+)
Give the electrolyte correspondent to the given
Has an intracellular to extracellular ratio of 25:1
Potassium (K+)
Give the electrolyte correspondent to the given
In terms of its intracellular to extracellular ratio, it is found more inside the cell than it is outside
Potassium (K+)
Give the electrolyte correspondent to the given
In terms of its intracellular to extracellular ratio, it is found more outside the cell than it is inside
Sodium (Na+)
Give the electrolytes correspondent to the given
What are the electrolytes that make use of the Flame Emission Spectrophotometry (FES) Method?
- Sodium (Na+)
- Potassium (K+)
- Magnesium (Mg 2+)
Give the electrolytes correspondent to the given
Aldosterone involvement
Sodium (Na+) and Potassium (K+)
Give the electrolytes correspondent to the given
Involvement of PTH, Vit. D, and Calcitonin
Calcium (Ca 2+) and Phosphorus
Give the electrolyte correspondent to the given
Albanese-Lein Method and Maruna Trinder Method
Sodium
Give the electrolytes correspondent to the given
Uses the Ion Selective Electrode (ISE) Method
- Sodium (Na+)
- Potassium (K+)
- Calcium (Ca 2+)
Give the electrolyte correspondent to the given
Uses a glass membrane electrode
Sodium (Na+)
Give the electrolytes correspondent to the given
Turbidimetric and Lockhead and Purcell Method
Potassium (K+)
Give the electrolyte correspondent to the given
Mercuric Titration and Mercuric Thiocyanate Method
Chloride (Cl-)
Give the electrolytes correspondent to the given
Colorimetric-Amperometric Titration
Chloride (Cl-)
Give the electrolytes correspondent to the given
Skegg’s Modification and Whitehorn Titration
Chloride (Cl-)
Give the electrolyte correspondent to the given
Cotlove Technique
Chloride (Cl-)
Give the electrolyte correspondent to the given
Clark and Collip under Colorimetric Method
Calcium (Ca 2+)
Give the electrolyte correspondent to the given
EDTA Titration
Calcium (Ca 2+)
Give the electrolyte correspondent to the given
O-Cresolphthalein, Alizarin, and Arsenazo III
Calcium (Ca 2+)
Give the electrolyte correspondent to the given
Fiske and Subbarow Method
Phosphorus
Give the electrolyte correspondent to the given
Titan Yellow under Colorimetric Method
Magnesium (Mg 2+)
Give the electrolyte correspondent to the given
- Acid Titration and pCO2 Electrode
- Alkalinization and Enzymatic Method
Bicarbonate (HCO3-)