Electrolytes (1) (M) Flashcards
What are electrolytes?
These are ions (minerals) w/c are capable of carrying an electric charge
Where are electrolytes found?
1) Blood
2) Urine
3) Tissues
4) Other body fluids
What is electroneutrality?
It is the balance of charges
What is the principle of electroneutrality?
Fluid always contains equal # of cations and anions
The dissociation of solutes into charged particles depends on what?
1) Chemical composition of the compound
2) Concentration of other charged particles in the medium
What are charged particles?
Ions
What is the main source of electrolytes?
Food sources
*What is the concentration of potassium (K^+)?
20 mEq
*What is the concentration of sodium (Na^+)?
45 mEq
*What is the concentration of chloride (Cl^-)?
35 mEq
What are the food sources where Na can be obtained?
1) Processed and canned foods
2) Cheese
3) Breads
4) Cereals
5) Sauces
6) Pickled foods
7) Commercial rice or pasta mixes
8) Condiments
What are the food sources where K can be obtained?
1) Green leafy vegetables (such as spinach and kale)
2) Tomatoes
3) Cucumbers
4) Pumpkin
5) Carrots
6) Potatoes and sweet potatoes
7) Bananas
8) Avocado
9) Beans and peas
10) Milk
11) Yoghurt
12) Meat
What are the food sources where Cl can be obtained?
1) Seafood
2) Seaweeds
3) Rye
4) Tomatoes
5) Lettuce
6) Celery
7) Olives
What are the food sources where calcium (Ca) can be obtained?
1) Milk
2) Milk alternatives
3) Soya
4) Nuts
5) Green leafy vegetables (such as broccoli, cabbage, and okra)
What are the food sources where magnesium (Mg) can be obtained?
1) Legumes
2) Nuts
3) Seeds
4) Fish
5) Whole grains
What are the food sources where phosphorus (P) can be obtained?
1) Milk
2) Milk products
3) Meat alternatives (such as beans, lentils, and nuts)
4) Grains
What are the electrolytes that fxns for volume and osmotic regulation?
1) Na
2) Cl
3) K
What are the electrolytes that fxns for myocardial rhythm and contractility?
1) K
2) Ca
3) Mg
What are the electrolytes w/c are impt cofactors in enzyme activation?
1) Ca
2) Mg
3) Zn
4) K
5) Cl
What is the electrolyte that fxns for the regulation of ATPase ion pumps?
Mg
What are the electrolytes that fxns for neuromuscular excitability?
1) K
2) Ca
3) Mg
What are the electrolytes that fxns for the production and use of ATP from glucose?
1) Mg
2) PO4
What are the electrolytes that fxns for the maintenance of acid-base balance?
1) HCO3
2) K
3) Cl
4) PO4
What is the electrolyte that fxns for the replication of DNA and the translation of mRNA?
Mg
What is osmolality?
It is a physical property of a solution that is based in the concentration of solutes per kilogram of solvent (w/w)
The concentration of solutes in osmolality is expressed as what?
Millimoles
Why is osmolality in plasma impt?
Because it is the parameter to w/c the hypothalamus responds
The regulation of osmolality also affects what?
Na^+ concentration in plasma
Why is Na^+ concentration in plasma also affected by the regulation of osmolality?
Largely because Na+ and its associated anions account for approx 90% of the osmotic activity in plasma
What is the normal plasma osmolality?
275 - 295 mOsm/kg of plasma H2O
How to maintain a normal plasma osmolality?
The osmoreceptors present in the hypothalamus respond quickly to small changes in osmolality
A 1% - 2% increase in osmolality causes what?
Causes a fourfold increase in the circulating concentration of AVP (arginine vasopressin)
What is the result of 1% - 2% decrease in osmolality?
The AVP production is shut off
What is the normal reference range for osmolality in the serum?
275 - 295 mOsm/kg
What is the normal reference range for osmolality in the urine (24 hr urine sx)?
300 - 900 mOsm/kg
What is the normal reference range for osmolality in the urine/serum ratio?
1.0 - 3.0
What is the normal reference range for osmolality in the random urine?
50 - 1,200 mOsm/kg
What is the normal reference range for osmolality in the osmolal gap?
5 - 10 mOsm/kg
What is the other term for sodium?
Natrium
Where can sodium (Na) be found?
It is present in all body fluids
Where can the highest concentration of Na be found?
1) In the blood
2) In the extracellular fluid (ECF)
What is the major extracellular cation?
Na
Since Na is the major extracellular cation, hence, it is considered as what?
Major contributor of osmolality
What are the fxns of Na?
1) It has a central role in maintaining the normal distribution of H2O in the body
2) It has a central role in maintaining the osmotic pressure in the ECF compartments
3) It helps in controlling BP
4) It helps in proper fxning of muscles and nerves
What is the normal reference range of Na in serum and/or plasma?
135 - 145 mmol/L
What is the normal reference range of Na in 24 hr urine?
40 - 220 mmol/d (varies w/ diet)
What is the normal reference range of Na in the cerebrospinal fluid (CSF)?
135 - 150 mmol/L
What are the sxs that can be used for determination of Na lvls?
1) Serum
2) Plasma
3) 24 hr urine
4) CSF
The plasma concentration of Na depends on greatly on what?
Intake and excretion of H2O
Where can Na be obtained?
1) Food
2) Drink
Where is Na primarily lost?
1) Sweat
2) Urine
What is responsible for the regulation of Na lvl in the body?
Kidneys
What are the mechanisms on maintaining Na lvls?
1) Intake of H2O in response to thirst (as response to plasma osmolality)
2) Excretion of H2O (affected by AVP)
3) Blood volume status
How can healthy kidneys maintain a consistent lvl of Na in the body?
By adjusting the amt excreted in the urine
What are the mechanisms on how healthy kidneys maintain a consistent lvl of Na in the body?
1) By producing hormones that can increase or decrease the amt of Na eliminated in urine
2) By producing a hormone that prevents H2O losses
3) By controlling thirst
What is the hormone responsible for increasing the amt of Na eliminated in the urine?
Natriuretic peptides
What is the hormone responsible for decreasing the amt of Na eliminated in the urine?
Aldosterone
What are the hormones that are responsible for preventing H2O losses?
1) ADH or
2) Vasopressin (AVP)
What is the effect / mechanism present as a result of even a 1% increase in blood Na?
It will make the pt thirsty and cause the pt to drink H2O, hence, the pt’s Na lvl is returned to normal
What are the systems where abnormal blood Na can occur is some problem w/ 1 of these systems is present?
1) When the lvl of Na in the blood changes, the H2O content in the body also changes
2) There could be too little fluid or w/ too much fluid
What is the condition where there is too little fluid?
Dehydration
What is the condition where there is too much fluid?
Edema
What is hyponatremia?
There is a low lvl of Na in the blood (< 135 mmol/L)
What decreased Na lvl is considered as clinically significant?
< 130 mmol/L
What is the most common electrolyte disorder?
Hyponatremia
What are the causes of hyponatremia?
1) Increased Na^+ loss
2) Increased H2O retention
3) H2O imbalance
Na can also be classified accdg to what?
Accdg to serum / plasma osmolality
What are the classifications of Na according to serum / plasma osmolality?
1) Low osmolality
2) Normal osmolality
3) High osmolality
The symptoms of a pt w/ hyponatremia depends on what?
Serum lvl
What are the symptoms that a pt w/ Na lvl of 125 - 130 mmol/L possess?
Primary GI symptoms
What are the symptoms that a pt w/ Na lvl of < 125 mmol/L possess?
1) Nausea
2) Vomiting
3) Muscular weakness
4) Headache
5) Lethargy
6) Ataxia
What are the symptoms if a pt has severe hyponatremia?
1) Muscle twitching
2) Seizures
3) Coma
4) Death
What is it called if a pt has Na lvl of < 120 mmol/L for 48 hrs or less?
Acute hyponatremia
A pt having Na lvl of < 120 mmol/L is considered as what?
Medical emergency
What is the treatment for hyponatremia?
Treatment is directed at the correction of the condition that caused either H2O loss or Na^+ loss in excess of H2O loss
What are the causes of hyponatremia?
1) Increased Na loss
2) Increased H2O retention
3) H2O imbalance
What are the causes of increased Na loss?
1) Hypoadrenalism
2) K deficiency
3) Diuretic use
4) Ketonuria
5) Salt-losing nephropathy
6) Prolong vomiting or diarrhea
7) Severe burns
What are the causes of increased H2O retention?
1) Renal failure
2) Nephrotic syndrome
3) Hepatic cirrhosis
4) Congestive heart failure (CHF)
What are the causes of H2O imbalance?
1) Excess H2O intake
2) Syndrome of inappropriate arginine vasopressin hormone secretion (/ syndrome of inappropriate antidiuretic hormone) (SIADH)
3) Pseudohyponatremia
What are the classifications of hyponatremia by osmolality?
1) W/ low osmolality
2) W/ normal osmolality
3) W/ high osmolality
What are the causes of w/ low osmolality (as a classification of hyponatremia by osmolality)?
1) Increased Na loss
2) Increased H2O retention
What are the causes of w/ normal osmolality (as a classification of hyponatremia by osmolality)?
1) Increased nonsodium cations
2) Lithium excess
3) Increased gamma globulins- cationic (present in cases of multiple myeloma)
4) Severe hyperkalemia
5) Severe hypermagnesemia
6) Severe hypercalcemia
7) Pseudohyponatremia
8) Hyperlipidemia
9) Hyperproteinemia
10) Pseudohyperkalemia (due to in-vitro hemolysis)
What are the causes of w/ high osmolality (as a classification of hyponatremia by osmolality)?
1) Hyperglycemia
2) Mannitol infusion
What is pseudohyponatremia?
It is the reduction of serum Na concentration caused by a systematic error in measurement
Pseudohyponatremia is usually caused by what?
By the presence of excess lipids in serum
Are there Na ions dissolved in lipids?
None
How to get the concentration of Na via the application of flame photometry?
If the absolute amt of Na in a given volume of serum is determined via flame photometry, this value is divided by the sx volume to get the concentration
What is the consideration that should be observed if flame photometry is done in connection to pseudohyponatremia?
A part of the sx volume is lipid that has no Na, hence, a falsely low volume of Na can be obtained
What is hypernatremia?
High lvl of Na in the blood (145 mmol/L >)
Hypernatremia is from what?
Excess loss of H2O
The origin of hypernatremia w/c is excess loss of H2O is relative to what?
1) Na^+ loss
2) Decreased H2O intake, or
3) Increased Na^+ intake or retention
True or False
In terms of occurrence, hypernatremia is less commonly seen in hospital pt compared to hyponatremia
True
Hypernatremia commonly occurs in pts who are what?
In pts who may be thirsty but who are unable to ask for or obtain H2O (ex. adults w/ altered mental status and infants)
Chronic hypernatremia in an alert pt is indicative of what?
Hypothalamic disease
What are the causes of hypernatremia?
1) Dehydration from not drinking enough fluids
2) Diarrhea
3) Kidney dysfunction
4) Diuretics
5) Excessive sweating
6) Hormonal imbalance (ADH and aldosterone)
7) Diabetes insipidus (DI) (copious production of dilute urine: 3 - 20 L/day)
8) Excess ingestion of Na
9) Administration of hypertonic solutions of Na^+
What is necessary and should be done to evaluate the cause of hypernatremia?
Measurement of urine osmolality
What is the Na lvl of the pt if the pt has hypernatremia (if urine is used as sx; in relation to urine osmolality)?
150 mmol/L
What are the classifications of hypernatremia (150 mmol/L) related to urine osmolality?
1) Urine osmolality (< 300 mOsm/kg)
2) Urine osmolality (300 - 700 mOsm/kg)
3) Urine osmolality (700 mOsm/kg >)
What is the cause of urine osmolality being < 300 mOsm/kg?
DI (whereas there is impaired secretion of AVP or kidneys cannot respond to AVP)
What are the causes of urine osmolality being 300 - 700 mOsm/kg?
1) Partial defect in AVP release or response to AVP
2) Osmotic diuresis
What are the causes of urine osmolality being 700 > mOsm/kg?
1) Loss of thirst
* 2) Insensible loss of H2O (breathing, skin)
3) GI loss of hypotonic fluid
4) Excess intake of Na
What is the meaning of AVP?
Arginine vasopressin hormone
What is the other term for AVP?
Antidiuretic hormone (ADH)
What are the symptoms if pt has hypernatremia?
Commonly involve the CNS:
1) Altered mental status
2) Lethargy
3) Irritability
4) Restlessness
5) Seizures
6) Muscle twitching
7) Hyperreflexes
8) Fever
9) Nausea
10) Vomiting
11) Difficult respirations
12) Increased thirst
Serum Na^+ of 160 mmol/L > is associated w/ a mortality of what percentage?
60 - 75%
What is the treatment for hypernatremia?
Treatment is directed at correction of the underlying condition that caused the H2O depletion of Na^+ retention
What must be the way of correcting hypernatremia?
It must be corrected gradually
Why must hypernatremia be corrected gradually?
Because if correction of hypernatremia is done too rapidly, it can induce cerebral edema and death
What are the sxs that can be used for determination of Na lvls?
1) Serum
2) Plasma
3) 24 hr urine
4) Sweat
What are the suitable anticoagulants that should be used if plasma is the sx that will be used for determination of Na lvls?
1) Lithium heparin
2) Ammonium heparin
3) Lithium oxalate
What are the methods for determination of Na lvls?
1) Ion-Selective Electrode (ISE)
2) Atomic Absorption Spectrophotometry (AAS)
3) Flame Emission Spectrophotometry (FES)
What is the most routinely used method in terms of determination of Na lvls?
ISE
What is the major intracellular cation?
K
What are the fxns of K?
1) For regulation of neuromuscular excitability
2) For the contraction of the heart
3) Intracellular fluid (ICF) volume
4) H^+ concentration
Plasma K^+ affects what?
Affects the resting membrane potential (RMP) of the cell (RM is closer to zero)
Since plasma K affects the RMP of the cell, thereby it affects what?
Cell excitability
Where can K be obtained?
1) Food
2) Drink
K is lost primarily in what?
Urine
Some of the K are lost in what?
1) Digestive tract
2) Sweat
What is the primary cause of hypokalemia / hyperkalemia?
Dietary deficiency or excess (in rare conditions)
What is the result if a pt has preexisting condition?
It only enhances the degree of hypokalemia / hyperkalemia
What is the normal reference range of K in the serum?
3.5 - 5.1 mmol/L
What is the normal reference range of K in the plasma for males?
3.5 - 4.5 mmol/L
What is the normal reference range of K in the plasma for females?
3.4 - 4.4 mmol/L
What is the normal reference range of K in the 24 hr urine?
25 - 125 mmol/d
K is impt to what?
1) Heart
2) Digestive fxns
3) Muscle fxns
K lvls are mainly controlled by what?
Aldosterone
What is aldosterone?
It is a hormone produced by the adrenal glands in the kidneys
What are the 3 factors that influence the distribution of K^+ between cells and ECF?
1) K^+ loss frequently occurs whenever the Na^+, K^+-ATPase pump is inhibited by conditions (such as hypoxia, hypomagnesemia, or digoxin overdose)
2) Insulin promotes acute entry of K^+ into skeletal muscle and liver by increasing Na^+, K^+-ATPase activity
3) Catecholamines (such as epinephrine) promote cellular entry of K^+, whereas propanolol impairs cellular entry of K^+
What is the fxn of epinephrine?
It is a β2- stimulator
What is the fxn of propanolol?
It is a β- blocker
In connection to K, exercise causes what?
It causes K^+ release from the muscle cells
Is the effect of exercise whereas it causes K^+ release from the muscle cells reversible or irreversible? When is the effect reversible / irreversible?
It is reversible after several mins of rest
Forearm exercise during venipuncture can cause what?
Erroneous high plasma K^+ concentration
Hyperosmolality, as w/ uncontrolled DM causes what and leads to what?
It causes H2O to diffuse from the cells carrying K^+ w/ it leading to the gradual depletion of K^+ if kidney fxn is normal
What is the effect / result of cellular breakdown (in connection to K)?
It releases K^+ into the ECF
What are the conditions that can cause cellular breakdown?
1) Severe trauma
2) Tumor lysis syndrome
3) Massive blood transfusions
What is hypokalemia?
It is a condition where there is low lvl of K in the blood?
What is the most common cause of hypokalemia?
Therapy w/ diureticts (/ diuretics)
What are the causes of hypokalemia?
1) Gastrointestinal loss
a. Vomiting
b. Diarrhea
c. Gastric suction
d. Intestinal tumor
e. Malabsorption
f. Cancer therapy (such as chemotherapy and radiation therapy)
g. Large doses of laxatives
2) Renal loss
a. Diuretics (such as thiazides and mineralocorticoids)
b. Nephritis
c. Renal tubular acidosis
d. Hyperaldosteronism
e. Cushing’s syndrome
f. Hypomagnesemia
g. Acute leukemia
3) Cellular shift
a. Alkalosis
b. Insulin overdose
4) Decreased intake
What is the K lvl that is considered as mild hypokalemia?
3 - 3.4 mmol/L
True or False
Mild hypokalemia usually causes no symptoms
True
A larger decrease in K lvls (< 3 mmol/L) can cause what symptoms?
1) Muscle weakness
2) Cramping
3) Twitches
4) Paralysis
Abnormal heart rhythms can develop w/ whom?
It can develop to pts who have a heart disorder or are taking digoxin even when there is only mild hypokalemia
What may be the result / effect if hypokalemia lasts for an extended time?
Kidney problems may develop
What is the cause if pt has developed kidney problems (due to hypokalemia w/c lasted for an extended time)?
It causes the pt to urinate frequently and drink large amts of H2O
What is the treatment for hypokalemia?
Oral KCl replacement of K^+ over several days
What is the treatment (/ method of correction) for chronic mild hypokalemia?
It can be corrected simply by including food w/ high K^+ content in the diet
What are the foods that have high K^+ content w/c can correct chronic mild hypokalemia if these foods ate eaten?
1) Dried fruits
2) Nuts
3) Bran cereals
4) Bananas
5) Orange juice
What is hyperkalemia?
It is the condition whereas there is high lvl of K in the blood
What are the causes of hyperkalemia?
1) Decreased renal excretion
a. Acute or chronic renal failure (GFR < 20 mL/min)
b. Hypoaldosteronism
c. Addison’s disease
d. Diuretics
2) Cellular shift
a. Acidosis
b. Muscle / cellular injury
c. Chemotherapy
d. Leukemia
e. Hemolysis
3) Increased intake
a. Oral or intravenous K replacement therapy
4) Artifactual
a. Sx hemolysis
b. Thrombocytosis
c. Prolonged tourniquet use or excessive fist clenching
Pts w/ hyperkalemia often have what underlying disorders?
1) Renal insufficiency
2) DM
3) Metabolic acidosis
* w/c contributes to hyperkalemia
Hyperkalemia causes what?
Cell damage
What are the different mechanisms of cell damage that is caused by hyperkalemia?
1) Rhabdomyolysis
2) Hemolysis
3) Kidney failure
What are the symptoms if pt has hyperkalemia (8 mmol/L > or equal to)?
1) Muscle weakness
2) Tingling
3) Numbness
4) Mental confusion by altering neuromuscular condition
What is the clinical manifestation of a pt w/ severe hyperkalemia?
Abnormal heart rhythms
If the pt’s K lvls is very high, what can be its clinical manifestation to the pt?
The pt’s heart can stop beating
When should treatment be initiated?
When serum K^+ is 6.0 - 6.5 mmol/L
What is the action of Ca^2+ as a treatment for hyperkalemia?
It provides immediate but short-lived protection to the myocardium against the effects of hyperkalemia
What treatment can be done / used if other measures / treatments fail?
Hemodialysis
What must be done to the sx for determination of K lvls?
The sx must be properly collected
Why should the sx must be properly collected in terms of determination of K lvls?
To avoid artifactual hyperkalemia
*What are the errors that can occur in terms of sx collection (for the determination of K lvls)?
1) Coagulation (whereas K^+ releases from PLTs)
2) Thrombocytosis
3) Tourniquet left on the arm too long (excessive exercising of forearm or fist)
What are the sxs that can be used for determination of K lvls?
1) Serum
2) Plasma (collected via the use of heparin)
3) Urine
What are the methods that can be used for determination of K lvls?
1) ISE
2) AAS
3) FES
What is the most routinely used method for determination of K lvls?
ISE
In ISE (as a method for determination of K lvls), what is the membrane used?
Valincomycin membrane
What is the major extracellular anion?
Cl
Cl concentrations mirror what electrolyte concentration?
Na concentration
True or False
The increase or decrease in Cl concentrations has same reasons w/ the increase or decrease of Na concentrations
True
*What is the relationship between Cl and Na?
Cl has a indirect relationship w/ Na
What happens to blood Cl lvls when there is acid-base imbalance?
Blood Cl lvls can change independently of Na
What are the fxns of Cl?
1) It acts as a buffer
2) It helps maintain electrical neutrality at the cellular lvl (by moving into or out of the cells as needed)
What is the effect brought to Cl lvl after every meal (explain its principle / mechanism)?
After eating, the stomach produces acid (HCl) using the Cl in blood and so there is usually slight drop of CL^- lvl after every meal
What almost completely absorbs Cl^- from diet?
By intestinal tract
Excess Cl^- is excreted in what?
1) Urine
2) Sweat
What are the 2 ways (/ mechanisms) that Cl^- maintains electrical neutrality?
1) Na^+ is reabsorbed along w/ Cl^- in the proximal tubules. Available Cl^- limits Na^+ reabsorption
2) Cl shift - CO2 generated by cellular metabolism within the tissue diffuses out into both the plasma and the RC. In the RC, CO2 forms carbonic acid (H2CO3), w/c splits into H^+ and HCO3^-. Deoxyhgb buffers H^+, whereas the HCO3^- diffuses out into the plasma and Cl^- diffuses into the RC to maintain the electric balance of the cell
What is hyperchloremia?
It is a condition whereas there is high lvl of Cl in the blood
What is hypochloremia?
It is a condition whereas there is low lvl of Cl in the blood
What are the causes of hyperchloremia?
1) Dehydration
2) Conditions w/ high blood Na
a. Cushing syndrome
b. Kidney disease
3) Too much base is lost from the body (producing metabolic acidosis)
4) When a pt hyperventilates (causing respiratory alkalosis)
What are the symptoms of a pt w/ hyperchloremia?
Symptoms often resembles that of hypernatremia
What are the causes of hypochloremia?
1) It occurs w/ any disorder that causes low blood Na
2) CHF
3) Prolonged vomiting
4) Gastric suction
5) Addison disease
6) Emphysema
7) Other chronic lung diseases
What are the symptoms of a pt w/ hypochloremia?
Symptoms often resembles that of hyponatremia
What are the sxs that can be used for determination of Cl determination?
1) Serum
2) Plasma
What anticoagulant should be used when plasma will be used as a sx for determination of Cl lvls?
Lithium heparin
What are the methods that can be used for determination of Cl lvls?
1) ISE
2) Mercurimetric Titration (Schales-Schales)
3) Colorimetric method
4) Amperometric-Coulometric Titration (Cotlove Chloridometer)
What is the most routinely used method for determination of Cl lvls?
ISE
What are used in colorimetric method (as a method for determination of Cl lvls)? Explain its principle
It uses mercuric thiocyanate and ferric nitrate to form a red-colored complex
What is the wavelength used for colorimetric method?
480 nm
What is the principle and mechanism of amperometric-coulometric titration?
Coulometric generation of Ag^+ w/c combine w/ Cl^- to quantitate the Cl^- concentration
When all Cl^- in a pt is bound to Ag^+, excess or free Ag^+ is used to indicate the endpoint. As Ag^+ accumulates, the coulometric generator and timer are turned off. The elapsed time is used to calculate the concentration of Cl^- in the sx
What is the principle of rxn of amperometric-coulometric titration?
Ag^2+ + 2Cl^- -> AgCl2
What is the normal reference range for Cl in plasma and/or serum?
98 - 107 mmol/L
What is the normal reference range for Cl in 24 hr urine?
110 - 250 mmol/d (varies w/ diet)
What is the 2nd most abundant anion in the body?
Bicarbonate (HCO3^-)
The production of HCO3 in the body results from what?
From the dissociation of H2CO3 w/c is produced from the formation of CO2 during metabolism
What is the characteristic of HCO3?
It also works w/ other electrolytes (Na, K, and Cl) to maintain electrical neutrality at the cellular lvl
What is the aim of bicarbonate test?
It measures the total amt of carbon dioxide (CO) in the blood, w/c occurs mostly in the form of HCO3^-
What is the result of measuring HCO3 as part of an electrolyte or metabolic panel?
It may help diagnose an electrolyte imbalance or acidosis / alkalosis
What are the major organs involved in regulating blood pH?
1) Lungs
2) Kidneys
How does the lungs and kidneys regulate blood pH?
Through the removal of excess HCO3
*What are the mechanisms for regulation of HCO3?
1) The lungs flush acid out of the body by exhaling CO2
2) The kidneys eliminate acids in the urine and regulate the concentration of HCO3 in blood
What are the drugs that may increase HCO3 lvls?
1) Fludrocortisone
2) Barbiturates
3) Bicarbonates
4) Hydrocortisone
5) Diuretics
6) Steroids
What are the drugs that may decrease HCO3 lvls?
1) Methicillin
2) Nitrofurantoin
3) Tetracycline
4) Thiazine diuretics
5) Triamterene
What is the normal reference range of HCO3 in plasma and serum (both from venous blood)?
23 - 29 mmol/L
What are the fxns of electrolyte panel?
It measures the blood lvls of the main electrolytes in the body
2) It is used to identify an electrolyte, fluid, or pH imbalance
3) It is used to investigate conditions (such as dehydration, kidney disease, lung disease, or heart conditions)
What are the main electrolytes in the body w/c are measured via electrolyte panel?
1) Na
2) K
3) Cl
4) HCO3
In electrolyte panel, HCO3 is sometimes reported as what?
Total CO2
What are the 2 types / conditions of pH imbalance?
1) Acidosis
2) Alkalosis
What are the symptoms (w/c the pt exhibits) w/c serves as indication that electrolyte panel should be ordered?
1) Fluid accumulation (edema)
2) Nausea
3) Vomiting
4) Weakness
5) Confusion
6) Irregular heartbeat (cardiac arrhythmias)
What are the methods that can be used for electrolyte panel?
1) ISE
2) Enzymatic
What are the sxs that can be used for electrolyte panel?
1) Serum
2) Plasma
What is the preferred sx to be used for electrolyte panel?
Serum
What are the containers / evacuated tubes that can / should be used for electrolyte panel?
1) Gel-barrier tube
2) Red-top tube
3) Green-top tube (heparin)
What is the preferred container or evacuated tube to be used for electrolyte panel?
Gel-barrier tube
When is the use of red-top and green-top tubes acceptable in electrolyte panel?
When it is centrifuged within 45 mins and the serum of plasma is removed and placed in a tightly-stoppered 2ndary tube
What is the sx consideration that should be observed for electrolyte panel?
Hemolysis should be avoided
In connection to electrolyte panel, what should be done if there is a single electrolyte imbalance?
Repeat tests may be done to that particular electrolyte for monitoring until it resolves
In connection to electrolyte panel, what should be done if there is acid-base imbalance?
Additional test for blood gases may be ordered
*What are the actions that should be done if acid-base imbalance is present (in connection to electrolyte panel)?
1) Measure the pH, O2, and CO2 lvls in an arterial blood sx
2) Evaluate the severity of the imbalance and useful in monitoring response to treatment
What is the normal pH range of arterial blood?
7.35 - 7.45
What is the survival pH range of arterial blood?
6.8 - 8.0
What is the pH value of arterial blood w/c is considered as acidosis?
6.8 - 7.35
What is the pH value of arterial blood w/c is considered as alkalosis?
7.45 - 8.0
What is the other term for basic metabolite panel?
Chem 7
What is basic metabolite panel?
It is a set of tests that provides info about the current status of a person’s metabolism (including health of the kidneys, blood glucose lvl, electrolyte and acid/base balance)
Where is basic metabolite panel often ordered?
In the emergency room (ER) setting
Why is basic metabolite panel often ordered in the ER?
Because results can indicate acute problems (such as kidney failure, insulin shock or diabetic coma, respiratory distress, or heart rhythm changes)
What are the tests that are included in basic metabolic panel?
1) Kidney tests (BUN, and creatinine [CR])
2) Electrolytes (Na, Cl, K, and HCO3)
3) Glucose test (GLU)
4) Test for Ca (sometimes included)
What are the sxs that can be used for basic metabolite panel?
1) Serum
2) Plasma
What is the preferred sx that should be used for basic metabolite panel?
Serum
What are the evacuated tubes that can be used for basic metabolite panel?
1) Gel-barrier tube
2) Red-top tube
3) Green-top tube (heparin)
What is the evacuated tube that is preferred to be used for basic metabolic panel?
Gel-barrier tube
What is the pt preparation that should be done prior to sx collection for basic metabolite panel?
Blood may be drawn after 10 - 12 hrs of fasting
True or False
Blood can be collected on a random basis (in emergency situations) for basic metabolite panel
True
What is done to the results of basic metabolite panel?
Results of the tests are evaluated together to look for patterns of a disease condition
What is anion gap?
It is the measurement of the difference (gap) between the negatively charged and positively charged electrolytes
What may be the sign if a pt’s anion gap is either too high or too low?
It may be a sign of a disorder in the pt’s:
1) Lungs
2) Kidneys
3) Other organ systems
What is acidosis?
It is a condition where there is too much acid in the blood
What is alkalosis?
It is where the pt’s blood does not have enough acid
What is the formula for anion gap (AG)?
AG = Na - (Cl + HCO3)
What is the most abundant mineral in the body?
Ca
What is the percentage of distribution of Ca and where are these percentages found?
1) Bones (99%)
2) Circulates in the blood (1%)
What are the 3 types of Ca?
1) Free or ionized
2) Bound to plasma proteins
3) Complexed to anions
What are the corresponding percentages of the different types of Ca?
1) Free or ionized (50%)
2) Bound to plasma proteins (40%)
3) Complexed to anions (10%)
What is the characteristic of free Ca?
It is metabolically active
What are the fxns of Ca?
1) It helps build and maintain strong bones and teeth
2) It is essential for cell signaling and fxning of muscles, nerves, and heart
3) It is also needed for proper blood clotting
What are the hormones that regulate Ca?
1) Calcitonin
2) Vitamin D
3) Parathyroid hormone (PTH)
True or False
Ca lvls are not tightly controlled
False, because Ca lvls are tightly controlled
What happens if the pt’s Ca lvls are too low?
Ca is taken from the bone to the circulation to maintain blood concentrations
When does PTH respond?
When there is a decrease in Ca^2+ in the blood
Where does PTH act?
1) Kidney
2) Bones
What is vit D3?
It is a cholecalciferol
What is the mechanism for vit D w/c is a way to regulate Ca?
Vit D3 is converted to 25-hydroxycholecalciferol (25-[OH]-D3) in the kidney w/c is then converted to dihydroxycholecalciferol (1,25-[OH]-D3)
Vit D3 -> 25-[OH]-D3 -> 1,25-[OH]-D3
Where does the absorption of vit D happen?
In the intestine
What is the result of absorption of vit D in the intestine?
It enhances the effect of PTH or bone resorption
What is the action of calcitonin?
It lowers Ca^2+
How does calcitonin lower Ca^2+?
By inhibiting the actions of both PTH and vit D
What is hypocalcemia?
It is a condition where there is low lvl of Ca in the blood
What are the causes of hypocalcemia?
1) Hypoparathyroidism
2) Hypomagnesemia
3) Vit D deficiency
4) Kidney dysfunction
5) Low consumption of Ca
6) Pancreatitis
What are the symptoms present if a pt has hypocalcemia?
There are usually no symptoms
What are the clinical manifestations that may be developed due to long-term hypocalcemia?
1) Dry scaly skin
2) Brittle nails
3) Coarse hair
What may be the clinical manifestations if a pt has extremely low lvls of Ca?
1) Tingling
2) Muscle aches
3) Spasms in the throat muscles
4) Stiffening and spasms of muscles
5) Seizures
6) Abnormal heart rhythms
What is hypercalcemia?
It is a condition whereas there is a high lvl of Ca in the blood
What are the causes of hypercalcemia?
1) Primary hyperparathyroidism
2) Too much Ca intake
3) Too much vit D intake
4) Cancers
5) Bone disorder
6) Inactivity (immobilized or paralyzed)
What are the symptoms of a pt w/ hypercalcemia?
1) Constipation
2) Nausea
3) Vomiting
4) Abdominal pain
5) Loss of appetite
6) Dehydration
7) Increased thirst
What can be the clinical manifestations if a pt has severe hypercalcemia?
1) Brain dysfunction w/ confusion
2) Emotional disturbances
3) Delirium
4) Hallucinations
5) Coma
What may be the result of long-term hypercalcemia?
Kidney stones containing Ca
What are the sxs that can be used for total Ca^2+ determination?
1) Serum
2) Lithium heparin plasma
What should be observed if lithium heparin plasma will be used as a sx for total Ca determination?
It should be anaerobic
What are the methods that can be used for total Ca determination?
1) Spectrophotometric analysis
2) Titration of fluorescent Ca complex w/ EDTA
3) AAS
4) Clark and Collip method (Redox titration)
What are used in spectrophotometric analysis for total Ca determination?
Metallochromic indicators
What are the most widely used metallochromic indicators that can be used for spectrophotometric analysis for total Ca determination?
1) Orthocresolphthalein complexone
2) Arsenazo III
What is the reference method for total Ca determination?
AAS
What is the method that can be done / used for determination of ionized Ca (type of Ca)?
ISE
What is the normal reference range for total Ca lvls in serum / plasma?
2.5 - 2.50 mmol/L (8.6 - 10.0 mg/dL)
What is the normal reference range for ionized Ca lvls in the serum?
2.15 - 2.50 mmol/L (4.6 - 5.3 mg/dL)
What is the normal reference range for ionized Ca lvls in the plasma?
1.03 mmol/L (4.1 - 4.9)
What is the principle of rxn if spectrophotometric method is used for determination of total Ca lvls?
Ca + o-Cresolphthalein complexone -> o-Cresolphthalein complexone (bounded w/ Ca^2+)
What is the wavelength used for spectrophotometric method for determination of total Ca lvls?
570 nm
What is the 2nd most abundant intracellular cation?
Mg
What is the 4th most abundant cation?
Mg
What are the fxns of Mg?
1) It is vital for energy production
2) It is vital for muscle contraction
3) It is vital for nerve fxn
4) It is vital / acts for the maintenance of strong bones
What are the sites where Mg is stored?
1) Bones
2) Soft tissue
What are the 3 types of Mg?
1) Free or ionized form
2) Associated w/ protein (albumin)
3) Complexed w/ other anions
What are the corresponding percentages of the different types of Mg?
1) Free or ionized form (50%)
2) Associated w/ protein (30%)
3) Complexed w/ other anions (20%)
What organ is largely controls and is responsible for the regulation of Mg lvls?
Kidney
What mechanism is done by the kidney to regulate Mg lvls?
It reabsorbs / excretes Mg^2+ as needed
True or False
The regulation of Mg lvls done by the kidney appears to be related to that of Ca^2+ and Na^+
True
What are the fxns of PTH in relation to regulation of Mg lvls?
1) It increases renal absorption
2) It enhances absorption in the intestine
What increases renal excretion (in connection to regulation of Mg lvls)?
1) Aldosterone
2) Thyroxine
What is hypomagnesemia?
It is condition whereas there is low lvl of Mg in the blood
What is the condition that is frequently observed in hospitalized pts in ICUs?
Hypomagnesemia
What are the causes of hypomagnesemia?
1) Starvation
2) Malabsorption of nutrients
3) Kidneys or intestines excrete too much Mg
A pt w/ hypomagnesemia is asymptomatic until serum lvl falls below what lvl?
Below 0.5 mmol/L
What are the symptoms of a pts w/ hypomagnesemia?
1) Nausea
2) Vomiting
3) Sleepiness
4) Weakness
5) Personality changes
6) Muscle spasms
7) Tremors
8) Loss of appetite
Severe hypomagnesemia can cause what especially in children?
Seizures
What is hypermagnesemia?
It is a condition whereas there is high lvl of Mg in the blood
What is the characteristic of hypermagnesemia?
It is an uncommon condition
Who are the pts whom hypermagnesemia usually develop?
It usually develops only when pts w/ kidney failure are given w/ Mg salts or if they take drugs that contain Mg
What are some drugs that contain Mg?
1) Antacids
2) Laxatives
What are the symptoms of a pt w/ hypermagnesemia?
1) Muscle weakness
2) Low BP
3) Impaired breathing
What may be the clinical manifestation brought about by severe hypermagnesemia to a pt?
It may cause the heart to stop beating
What are the sxs that can be used for determination of total serum Mg lvls?
1) Non-hemolyzed serum
2) Lithium heparinized plasma
3) 24 hr urine
What are the methods that can be used for the determination of total serum Mg lvls?
1) AAS
2) Photometric methods (on automated analyzers)
What is the characteristic of AAS as a method for determination of total serum Mg lvls?
It is the reference method but it is not routinely done in the clinical lab
What are used in photometric methods in terms of determination of total serum Mg lvls?
Metallochromic indicators
What are the metallochromic indicators that can be used for photometric methods for the determination of total serum Mg lvls?
1) Calmagite
2) Formazan dye
3) Magon
4) Titan yellow dye
What is the normal reference range for Mg lvls in the serum (via colorimetric method)?
0.63 - 1.0 mmol/L (1.26 - 2.10 mg/dL)
How is phosphate (PO4^-3) formed?
Almost all phosphorus in the body is combined w/ O2, forming phosphate
What is the charge of majority of PO4 in the body?
Majority are uncharged
What is the action of 85% of the body’s PO4?
These combine w/ Ca
Why does 85% of the body’s PO4 combine w/ Ca?
To help form bones and teeth
*What are the sites where smaller amts of phosphorus (/ PO4?) found?
1) Muscle
2) Nerve tissue
*What is the site where the rest of the phosphorus (/ PO4) found?
Found within cells throughout the body
What is the fxn of phosphorus?
It is used as a building block for several impt substances (including those used by the cell for energy [w/c are cell membranes and DNA])
What are responsible for the regulation of phosphorus?
1) Vit D
2) PTH
What is the action of vit D in terms of regulation of phosphorus lvls?
It increases the PO4 in the blood
What is the action of PTH in terms of regulation of phosphorus lvls?
It lowers blood concentration
What is hypophosphatemia?
It is a condition whereas there is low lvl of phosphorus in the blood
What are the types of hypophosphatemia?
1) Acute hypophosphatemia
2) Chronic hypophosphatemia
What are the causes of acute hypophosphatemia?
1) Severe undernutrition
2) Diabetic ketoacidosis
3) Severe alcoholism
4) Severe burns
5) Sudden drop (w/c may lead to abnormal heart rhythm or death)
What are the causes of chronic hypophosphatemia?
1) Hyperparathyroidism
2) Chronic diarrhea
3) Prolonged use of diuretics
4) Prolonged use of large amts of aluminum-containing antacids for a long time
5) Use of large amts of theophylline
What is the action of theophylline?
It is used to treat asthma
What are the symptoms of a pt w/ hypophosphatemia?
1) Muscle weakness
2) Stupor
3) Weakened bones (resulting to bone pain and fractures)
4) Loss of appetite
What is hyperphosphatemia?
It is a condition whereas there is high lvl of phosphorus in the blood
What is the characteristic of hyperphosphatemia?
It is rare except in pts w/ severe kidney dysfunction
What are the causes of hyperphosphatemia?
1) Hypoparathyroidism
2) Diabetic ketoacidosis
3) Crush injuries
4) Rhabdomyolysis
5) Sepsis
What are the symptoms of a pt w/ hyperphosphatemia?
Most do not have symptoms
What are the symptoms of a pt w/ severe kidney dysfunction if the pt has hyperphosphatemia?
Ca combines w/ phosphorus resulting to hypocalcemia
Ca and PO4 can form what in the body tissue?
Crystals (w/c calcify in the body tissue) (including within the walls of the blood vessels [arteriosclerosis])
What are the sxs that can be used for determination of phosphorus lvls?
1) Serum
2) Lithium heparin
3) 24 hr urine
What is the sx consideration that should be observed to the sx for determination of phosphorus lvls?
Hemolysis should be avoided
Why should hemolysis be avoided?
Because phosphorus is present in high concentration inside the RBCs
What are the methods that can be used for determination of phosphorus lvls?
1) Rxn of phosphate w/ ammonium molybdate (Fiske-Subbarow)
2) Reduction of phosphomolybdate to molybdenum blue w/c can be measured at 600 - 700 nm spectrophotometrically
3) Enzymatic method
What is the normal reference range of phosphorus lvls?
0.78 - 1.42 mmol/L (2.4 - 4.4 mg/dL)
