Electrolytes (1) (M) Flashcards
(335 cards)
1
Q
What are electrolytes?
A
These are ions (minerals) w/c are capable of carrying an electric charge
2
Q
Where are electrolytes found?
A
1) Blood
2) Urine
3) Tissues
4) Other body fluids
3
Q
What is electroneutrality?
A
It is the balance of charges
4
Q
What is the principle of electroneutrality?
A
Fluid always contains equal # of cations and anions
5
Q
The dissociation of solutes into charged particles depends on what?
A
1) Chemical composition of the compound
2) Concentration of other charged particles in the medium
6
Q
What are charged particles?
A
Ions
7
Q
What is the main source of electrolytes?
A
Food sources
8
Q
*What is the concentration of potassium (K^+)?
A
20 mEq
9
Q
*What is the concentration of sodium (Na^+)?
A
45 mEq
10
Q
*What is the concentration of chloride (Cl^-)?
A
35 mEq
11
Q
What are the food sources where Na can be obtained?
A
1) Processed and canned foods
2) Cheese
3) Breads
4) Cereals
5) Sauces
6) Pickled foods
7) Commercial rice or pasta mixes
8) Condiments
12
Q
What are the food sources where K can be obtained?
A
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
13
Q
What are the food sources where Cl can be obtained?
A
1) Seafood
2) Seaweeds
3) Rye
4) Tomatoes
5) Lettuce
6) Celery
7) Olives
14
Q
What are the food sources where calcium (Ca) can be obtained?
A
1) Milk
2) Milk alternatives
3) Soya
4) Nuts
5) Green leafy vegetables (such as broccoli, cabbage, and okra)
15
Q
What are the food sources where magnesium (Mg) can be obtained?
A
1) Legumes
2) Nuts
3) Seeds
4) Fish
5) Whole grains
16
Q
What are the food sources where phosphorus (P) can be obtained?
A
1) Milk
2) Milk products
3) Meat alternatives (such as beans, lentils, and nuts)
4) Grains
17
Q
What are the electrolytes that fxns for volume and osmotic regulation?
A
1) Na
2) Cl
3) K
18
Q
What are the electrolytes that fxns for myocardial rhythm and contractility?
A
1) K
2) Ca
3) Mg
19
Q
What are the electrolytes w/c are impt cofactors in enzyme activation?
A
1) Ca
2) Mg
3) Zn
4) K
5) Cl
20
Q
What is the electrolyte that fxns for the regulation of ATPase ion pumps?
A
Mg
21
Q
What are the electrolytes that fxns for neuromuscular excitability?
A
1) K
2) Ca
3) Mg
22
Q
What are the electrolytes that fxns for the production and use of ATP from glucose?
A
1) Mg
2) PO4
23
Q
What are the electrolytes that fxns for the maintenance of acid-base balance?
A
1) HCO3
2) K
3) Cl
4) PO4
24
Q
What is the electrolyte that fxns for the replication of DNA and the translation of mRNA?
A
Mg
25
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)
26
The concentration of solutes in osmolality is expressed as what?
Millimoles
27
Why is osmolality in plasma impt?
Because it is the parameter to w/c the hypothalamus responds
28
The regulation of osmolality also affects what?
Na^+ concentration in plasma
29
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
30
What is the normal plasma osmolality?
275 - 295 mOsm/kg of plasma H2O
31
How to maintain a normal plasma osmolality?
The osmoreceptors present in the hypothalamus respond quickly to small changes in osmolality
32
A 1% - 2% increase in osmolality causes what?
Causes a fourfold increase in the circulating concentration of AVP (arginine vasopressin)
33
What is the result of 1% - 2% decrease in osmolality?
The AVP production is shut off
34
What is the normal reference range for osmolality in the serum?
275 - 295 mOsm/kg
35
What is the normal reference range for osmolality in the urine (24 hr urine sx)?
300 - 900 mOsm/kg
36
What is the normal reference range for osmolality in the urine/serum ratio?
1.0 - 3.0
37
What is the normal reference range for osmolality in the random urine?
50 - 1,200 mOsm/kg
38
What is the normal reference range for osmolality in the osmolal gap?
5 - 10 mOsm/kg
39
What is the other term for sodium?
Natrium
40
Where can sodium (Na) be found?
It is present in all body fluids
41
Where can the highest concentration of Na be found?
1) In the blood
| 2) In the extracellular fluid (ECF)
42
What is the major extracellular cation?
Na
43
Since Na is the major extracellular cation, hence, it is considered as what?
Major contributor of osmolality
44
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
45
What is the normal reference range of Na in serum and/or plasma?
135 - 145 mmol/L
46
What is the normal reference range of Na in 24 hr urine?
40 - 220 mmol/d (varies w/ diet)
47
What is the normal reference range of Na in the cerebrospinal fluid (CSF)?
135 - 150 mmol/L
48
What are the sxs that can be used for determination of Na lvls?
1) Serum
2) Plasma
3) 24 hr urine
4) CSF
49
The plasma concentration of Na depends on greatly on what?
Intake and excretion of H2O
50
Where can Na be obtained?
1) Food
| 2) Drink
51
Where is Na primarily lost?
1) Sweat
| 2) Urine
52
What is responsible for the regulation of Na lvl in the body?
Kidneys
53
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
54
How can healthy kidneys maintain a consistent lvl of Na in the body?
By adjusting the amt excreted in the urine
55
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
56
What is the hormone responsible for increasing the amt of Na eliminated in the urine?
Natriuretic peptides
57
What is the hormone responsible for decreasing the amt of Na eliminated in the urine?
Aldosterone
58
What are the hormones that are responsible for preventing H2O losses?
1) ADH or
| 2) Vasopressin (AVP)
59
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
60
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
61
What is the condition where there is too little fluid?
Dehydration
62
What is the condition where there is too much fluid?
Edema
63
What is hyponatremia?
There is a low lvl of Na in the blood (< 135 mmol/L)
64
What decreased Na lvl is considered as clinically significant?
< 130 mmol/L
65
What is the most common electrolyte disorder?
Hyponatremia
66
What are the causes of hyponatremia?
1) Increased Na^+ loss
2) Increased H2O retention
3) H2O imbalance
67
Na can also be classified accdg to what?
Accdg to serum / plasma osmolality
68
What are the classifications of Na according to serum / plasma osmolality?
1) Low osmolality
2) Normal osmolality
3) High osmolality
69
The symptoms of a pt w/ hyponatremia depends on what?
Serum lvl
70
What are the symptoms that a pt w/ Na lvl of 125 - 130 mmol/L possess?
Primary GI symptoms
71
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
72
What are the symptoms if a pt has severe hyponatremia?
1) Muscle twitching
2) Seizures
3) Coma
4) Death
73
What is it called if a pt has Na lvl of < 120 mmol/L for 48 hrs or less?
Acute hyponatremia
74
A pt having Na lvl of < 120 mmol/L is considered as what?
Medical emergency
75
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
76
What are the causes of hyponatremia?
1) Increased Na loss
2) Increased H2O retention
3) H2O imbalance
77
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
78
What are the causes of increased H2O retention?
1) Renal failure
2) Nephrotic syndrome
3) Hepatic cirrhosis
4) Congestive heart failure (CHF)
79
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
80
What are the classifications of hyponatremia by osmolality?
1) W/ low osmolality
2) W/ normal osmolality
3) W/ high osmolality
81
What are the causes of w/ low osmolality (as a classification of hyponatremia by osmolality)?
1) Increased Na loss
| 2) Increased H2O retention
82
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)
83
What are the causes of w/ high osmolality (as a classification of hyponatremia by osmolality)?
1) Hyperglycemia
| 2) Mannitol infusion
84
What is pseudohyponatremia?
It is the reduction of serum Na concentration caused by a systematic error in measurement
85
Pseudohyponatremia is usually caused by what?
By the presence of excess lipids in serum
86
Are there Na ions dissolved in lipids?
None
87
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
88
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
89
What is hypernatremia?
High lvl of Na in the blood (145 mmol/L >)
90
Hypernatremia is from what?
Excess loss of H2O
91
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
92
True or False
In terms of occurrence, hypernatremia is less commonly seen in hospital pt compared to hyponatremia
True
93
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)
94
Chronic hypernatremia in an alert pt is indicative of what?
Hypothalamic disease
95
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^+
96
What is necessary and should be done to evaluate the cause of hypernatremia?
Measurement of urine osmolality
97
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
98
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 >)
99
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)
100
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
101
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
102
What is the meaning of AVP?
Arginine vasopressin hormone
103
What is the other term for AVP?
Antidiuretic hormone (ADH)
104
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
105
Serum Na^+ of 160 mmol/L > is associated w/ a mortality of what percentage?
60 - 75%
106
What is the treatment for hypernatremia?
Treatment is directed at correction of the underlying condition that caused the H2O depletion of Na^+ retention
107
What must be the way of correcting hypernatremia?
It must be corrected gradually
108
Why must hypernatremia be corrected gradually?
Because if correction of hypernatremia is done too rapidly, it can induce cerebral edema and death
109
What are the sxs that can be used for determination of Na lvls?
1) Serum
2) Plasma
3) 24 hr urine
4) Sweat
110
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
111
What are the methods for determination of Na lvls?
1) Ion-Selective Electrode (ISE)
2) Atomic Absorption Spectrophotometry (AAS)
3) Flame Emission Spectrophotometry (FES)
112
What is the most routinely used method in terms of determination of Na lvls?
ISE
113
What is the major intracellular cation?
K
114
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
115
Plasma K^+ affects what?
Affects the resting membrane potential (RMP) of the cell (RM is closer to zero)
116
Since plasma K affects the RMP of the cell, thereby it affects what?
Cell excitability
117
Where can K be obtained?
1) Food
| 2) Drink
118
K is lost primarily in what?
Urine
119
Some of the K are lost in what?
1) Digestive tract
| 2) Sweat
120
What is the primary cause of hypokalemia / hyperkalemia?
Dietary deficiency or excess (in rare conditions)
121
What is the result if a pt has preexisting condition?
It only enhances the degree of hypokalemia / hyperkalemia
122
What is the normal reference range of K in the serum?
3.5 - 5.1 mmol/L
123
What is the normal reference range of K in the plasma for males?
3.5 - 4.5 mmol/L
124
What is the normal reference range of K in the plasma for females?
3.4 - 4.4 mmol/L
125
What is the normal reference range of K in the 24 hr urine?
25 - 125 mmol/d
126
K is impt to what?
1) Heart
2) Digestive fxns
3) Muscle fxns
127
K lvls are mainly controlled by what?
Aldosterone
128
What is aldosterone?
It is a hormone produced by the adrenal glands in the kidneys
129
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^+
130
What is the fxn of epinephrine?
It is a β2- stimulator
131
What is the fxn of propanolol?
It is a β- blocker
132
In connection to K, exercise causes what?
It causes K^+ release from the muscle cells
133
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
134
Forearm exercise during venipuncture can cause what?
Erroneous high plasma K^+ concentration
135
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
136
What is the effect / result of cellular breakdown (in connection to K)?
It releases K^+ into the ECF
137
What are the conditions that can cause cellular breakdown?
1) Severe trauma
2) Tumor lysis syndrome
3) Massive blood transfusions
138
What is hypokalemia?
It is a condition where there is low lvl of K in the blood?
139
What is the most common cause of hypokalemia?
Therapy w/ diureticts (/ diuretics)
140
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
141
What is the K lvl that is considered as mild hypokalemia?
3 - 3.4 mmol/L
142
True or False
Mild hypokalemia usually causes no symptoms
True
143
A larger decrease in K lvls (< 3 mmol/L) can cause what symptoms?
1) Muscle weakness
2) Cramping
3) Twitches
4) Paralysis
144
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
145
What may be the result / effect if hypokalemia lasts for an extended time?
Kidney problems may develop
146
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
147
What is the treatment for hypokalemia?
Oral KCl replacement of K^+ over several days
148
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
149
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
150
What is hyperkalemia?
It is the condition whereas there is high lvl of K in the blood
151
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
152
Pts w/ hyperkalemia often have what underlying disorders?
1) Renal insufficiency
2) DM
3) Metabolic acidosis
* w/c contributes to hyperkalemia
153
Hyperkalemia causes what?
Cell damage
154
What are the different mechanisms of cell damage that is caused by hyperkalemia?
1) Rhabdomyolysis
2) Hemolysis
3) Kidney failure
155
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
156
What is the clinical manifestation of a pt w/ severe hyperkalemia?
Abnormal heart rhythms
157
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
158
When should treatment be initiated?
When serum K^+ is 6.0 - 6.5 mmol/L
159
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
160
What treatment can be done / used if other measures / treatments fail?
Hemodialysis
161
What must be done to the sx for determination of K lvls?
The sx must be properly collected
162
Why should the sx must be properly collected in terms of determination of K lvls?
To avoid artifactual hyperkalemia
163
*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)
164
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
165
What are the methods that can be used for determination of K lvls?
1) ISE
2) AAS
3) FES
166
What is the most routinely used method for determination of K lvls?
ISE
167
In ISE (as a method for determination of K lvls), what is the membrane used?
Valincomycin membrane
168
What is the major extracellular anion?
Cl
169
Cl concentrations mirror what electrolyte concentration?
Na concentration
170
True or False
The increase or decrease in Cl concentrations has same reasons w/ the increase or decrease of Na concentrations
True
171
*What is the relationship between Cl and Na?
Cl has a indirect relationship w/ Na
172
What happens to blood Cl lvls when there is acid-base imbalance?
Blood Cl lvls can change independently of Na
173
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)
174
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
175
What almost completely absorbs Cl^- from diet?
By intestinal tract
176
Excess Cl^- is excreted in what?
1) Urine
| 2) Sweat
177
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
178
What is hyperchloremia?
It is a condition whereas there is high lvl of Cl in the blood
179
What is hypochloremia?
It is a condition whereas there is low lvl of Cl in the blood
180
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)
181
What are the symptoms of a pt w/ hyperchloremia?
Symptoms often resembles that of hypernatremia
182
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
183
What are the symptoms of a pt w/ hypochloremia?
Symptoms often resembles that of hyponatremia
184
What are the sxs that can be used for determination of Cl determination?
1) Serum
| 2) Plasma
185
What anticoagulant should be used when plasma will be used as a sx for determination of Cl lvls?
Lithium heparin
186
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)
187
What is the most routinely used method for determination of Cl lvls?
ISE
188
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
189
What is the wavelength used for colorimetric method?
480 nm
190
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
191
What is the principle of rxn of amperometric-coulometric titration?
Ag^2+ + 2Cl^- -> AgCl2
192
What is the normal reference range for Cl in plasma and/or serum?
98 - 107 mmol/L
193
What is the normal reference range for Cl in 24 hr urine?
110 - 250 mmol/d (varies w/ diet)
194
What is the 2nd most abundant anion in the body?
Bicarbonate (HCO3^-)
195
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
196
What is the characteristic of HCO3?
It also works w/ other electrolytes (Na, K, and Cl) to maintain electrical neutrality at the cellular lvl
197
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^-
198
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
199
What are the major organs involved in regulating blood pH?
1) Lungs
| 2) Kidneys
200
How does the lungs and kidneys regulate blood pH?
Through the removal of excess HCO3
201
*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
202
What are the drugs that may increase HCO3 lvls?
1) Fludrocortisone
2) Barbiturates
3) Bicarbonates
4) Hydrocortisone
5) Diuretics
6) Steroids
203
What are the drugs that may decrease HCO3 lvls?
1) Methicillin
2) Nitrofurantoin
3) Tetracycline
4) Thiazine diuretics
5) Triamterene
204
What is the normal reference range of HCO3 in plasma and serum (both from venous blood)?
23 - 29 mmol/L
205
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)
206
What are the main electrolytes in the body w/c are measured via electrolyte panel?
1) Na
2) K
3) Cl
4) HCO3
207
In electrolyte panel, HCO3 is sometimes reported as what?
Total CO2
208
What are the 2 types / conditions of pH imbalance?
1) Acidosis
| 2) Alkalosis
209
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)
210
What are the methods that can be used for electrolyte panel?
1) ISE
| 2) Enzymatic
211
What are the sxs that can be used for electrolyte panel?
1) Serum
| 2) Plasma
212
What is the preferred sx to be used for electrolyte panel?
Serum
213
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)
214
What is the preferred container or evacuated tube to be used for electrolyte panel?
Gel-barrier tube
215
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
216
What is the sx consideration that should be observed for electrolyte panel?
Hemolysis should be avoided
217
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
218
In connection to electrolyte panel, what should be done if there is acid-base imbalance?
Additional test for blood gases may be ordered
219
*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
220
What is the normal pH range of arterial blood?
7.35 - 7.45
221
What is the survival pH range of arterial blood?
6.8 - 8.0
222
What is the pH value of arterial blood w/c is considered as acidosis?
6.8 - 7.35
223
What is the pH value of arterial blood w/c is considered as alkalosis?
7.45 - 8.0
224
What is the other term for basic metabolite panel?
Chem 7
225
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)
226
Where is basic metabolite panel often ordered?
In the emergency room (ER) setting
227
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)
228
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)
229
What are the sxs that can be used for basic metabolite panel?
1) Serum
| 2) Plasma
230
What is the preferred sx that should be used for basic metabolite panel?
Serum
231
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)
232
What is the evacuated tube that is preferred to be used for basic metabolic panel?
Gel-barrier tube
233
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
234
True or False
Blood can be collected on a random basis (in emergency situations) for basic metabolite panel
True
235
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
236
What is anion gap?
It is the measurement of the difference (gap) between the negatively charged and positively charged electrolytes
237
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
238
What is acidosis?
It is a condition where there is too much acid in the blood
239
What is alkalosis?
It is where the pt's blood does not have enough acid
240
What is the formula for anion gap (AG)?
AG = Na - (Cl + HCO3)
241
What is the most abundant mineral in the body?
Ca
242
What is the percentage of distribution of Ca and where are these percentages found?
1) Bones (99%)
| 2) Circulates in the blood (1%)
243
What are the 3 types of Ca?
1) Free or ionized
2) Bound to plasma proteins
3) Complexed to anions
244
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%)
245
What is the characteristic of free Ca?
It is metabolically active
246
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
247
What are the hormones that regulate Ca?
1) Calcitonin
2) Vitamin D
3) Parathyroid hormone (PTH)
248
True or False
Ca lvls are not tightly controlled
False, because Ca lvls are tightly controlled
249
What happens if the pt's Ca lvls are too low?
Ca is taken from the bone to the circulation to maintain blood concentrations
250
When does PTH respond?
When there is a decrease in Ca^2+ in the blood
251
Where does PTH act?
1) Kidney
| 2) Bones
252
What is vit D3?
It is a cholecalciferol
253
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
254
Where does the absorption of vit D happen?
In the intestine
255
What is the result of absorption of vit D in the intestine?
It enhances the effect of PTH or bone resorption
256
What is the action of calcitonin?
It lowers Ca^2+
257
How does calcitonin lower Ca^2+?
By inhibiting the actions of both PTH and vit D
258
What is hypocalcemia?
It is a condition where there is low lvl of Ca in the blood
259
What are the causes of hypocalcemia?
1) Hypoparathyroidism
2) Hypomagnesemia
3) Vit D deficiency
4) Kidney dysfunction
5) Low consumption of Ca
6) Pancreatitis
260
What are the symptoms present if a pt has hypocalcemia?
There are usually no symptoms
261
What are the clinical manifestations that may be developed due to long-term hypocalcemia?
1) Dry scaly skin
2) Brittle nails
3) Coarse hair
262
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
263
What is hypercalcemia?
It is a condition whereas there is a high lvl of Ca in the blood
264
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)
265
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
266
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
267
What may be the result of long-term hypercalcemia?
Kidney stones containing Ca
268
What are the sxs that can be used for total Ca^2+ determination?
1) Serum
| 2) Lithium heparin plasma
269
What should be observed if lithium heparin plasma will be used as a sx for total Ca determination?
It should be anaerobic
270
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)
271
What are used in spectrophotometric analysis for total Ca determination?
Metallochromic indicators
272
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
273
What is the reference method for total Ca determination?
AAS
274
What is the method that can be done / used for determination of ionized Ca (type of Ca)?
ISE
275
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)
276
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)
277
What is the normal reference range for ionized Ca lvls in the plasma?
1.03 mmol/L (4.1 - 4.9)
278
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+)
279
What is the wavelength used for spectrophotometric method for determination of total Ca lvls?
570 nm
280
What is the 2nd most abundant intracellular cation?
Mg
281
What is the 4th most abundant cation?
Mg
282
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
283
What are the sites where Mg is stored?
1) Bones
| 2) Soft tissue
284
What are the 3 types of Mg?
1) Free or ionized form
2) Associated w/ protein (albumin)
3) Complexed w/ other anions
285
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%)
286
What organ is largely controls and is responsible for the regulation of Mg lvls?
Kidney
287
What mechanism is done by the kidney to regulate Mg lvls?
It reabsorbs / excretes Mg^2+ as needed
288
True or False
The regulation of Mg lvls done by the kidney appears to be related to that of Ca^2+ and Na^+
True
289
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
290
What increases renal excretion (in connection to regulation of Mg lvls)?
1) Aldosterone
| 2) Thyroxine
291
What is hypomagnesemia?
It is condition whereas there is low lvl of Mg in the blood
292
What is the condition that is frequently observed in hospitalized pts in ICUs?
Hypomagnesemia
293
What are the causes of hypomagnesemia?
1) Starvation
2) Malabsorption of nutrients
3) Kidneys or intestines excrete too much Mg
294
A pt w/ hypomagnesemia is asymptomatic until serum lvl falls below what lvl?
Below 0.5 mmol/L
295
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
296
Severe hypomagnesemia can cause what especially in children?
Seizures
297
What is hypermagnesemia?
It is a condition whereas there is high lvl of Mg in the blood
298
What is the characteristic of hypermagnesemia?
It is an uncommon condition
299
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
300
What are some drugs that contain Mg?
1) Antacids
| 2) Laxatives
301
What are the symptoms of a pt w/ hypermagnesemia?
1) Muscle weakness
2) Low BP
3) Impaired breathing
302
What may be the clinical manifestation brought about by severe hypermagnesemia to a pt?
It may cause the heart to stop beating
303
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
304
What are the methods that can be used for the determination of total serum Mg lvls?
1) AAS
| 2) Photometric methods (on automated analyzers)
305
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
306
What are used in photometric methods in terms of determination of total serum Mg lvls?
Metallochromic indicators
307
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
308
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)
309
How is phosphate (PO4^-3) formed?
Almost all phosphorus in the body is combined w/ O2, forming phosphate
310
What is the charge of majority of PO4 in the body?
Majority are uncharged
311
What is the action of 85% of the body's PO4?
These combine w/ Ca
312
Why does 85% of the body's PO4 combine w/ Ca?
To help form bones and teeth
313
*What are the sites where smaller amts of phosphorus (/ PO4?) found?
1) Muscle
| 2) Nerve tissue
314
*What is the site where the rest of the phosphorus (/ PO4) found?
Found within cells throughout the body
315
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])
316
What are responsible for the regulation of phosphorus?
1) Vit D
| 2) PTH
317
What is the action of vit D in terms of regulation of phosphorus lvls?
It increases the PO4 in the blood
318
What is the action of PTH in terms of regulation of phosphorus lvls?
It lowers blood concentration
319
What is hypophosphatemia?
It is a condition whereas there is low lvl of phosphorus in the blood
320
What are the types of hypophosphatemia?
1) Acute hypophosphatemia
| 2) Chronic hypophosphatemia
321
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)
322
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
323
What is the action of theophylline?
It is used to treat asthma
324
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
325
What is hyperphosphatemia?
It is a condition whereas there is high lvl of phosphorus in the blood
326
What is the characteristic of hyperphosphatemia?
It is rare except in pts w/ severe kidney dysfunction
327
What are the causes of hyperphosphatemia?
1) Hypoparathyroidism
2) Diabetic ketoacidosis
3) Crush injuries
4) Rhabdomyolysis
5) Sepsis
328
What are the symptoms of a pt w/ hyperphosphatemia?
Most do not have symptoms
329
What are the symptoms of a pt w/ severe kidney dysfunction if the pt has hyperphosphatemia?
Ca combines w/ phosphorus resulting to hypocalcemia
330
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])
331
What are the sxs that can be used for determination of phosphorus lvls?
1) Serum
2) Lithium heparin
3) 24 hr urine
332
What is the sx consideration that should be observed to the sx for determination of phosphorus lvls?
Hemolysis should be avoided
333
Why should hemolysis be avoided?
Because phosphorus is present in high concentration inside the RBCs
334
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
335
What is the normal reference range of phosphorus lvls?
0.78 - 1.42 mmol/L (2.4 - 4.4 mg/dL)
