electrolytes Flashcards
1
Q
processes electrolytes involved in
A
Volume and osmotic regulation
Acid base balance Cofactors for enzyme activation
Blood coagulation
Neuromuscular activity
Hydration
2
Q
movement of ions happens either
A
active transport
passive transport
3
Q
if sample is intracellular what is will affect the it
A
hemolysis
4
Q
sodium is
A
-extracellular
-abundant cation in extracellular fluid 90%
5
Q
main ion that determines osmolality
A
sodium
6
Q
sodium reference range
A
135-145
7
Q
sodium renal threshold
A
110-130
8
Q
sodium potassium pump
A
3 sodium out and 2 potassium in
9
Q
main regulator of sodium
A
kidneys
-absorbed proximal tubules
10
Q
ADH- antidiuretic hormones released by
A
pituitary gland
aka vasopressin
11
Q
ADH directly related to
A
thirst
when sodium values increased, plasma osmolality increased = ADH turned on to dilute sodium
12
Q
renin produced by
A
kidneys
13
Q
RAAS system
A
renin aldosterone angiotensin system
14
Q
how does RAAS start
A
BP decreased, when sodium decreased— renin released into bloodstream
renin converts angiotensin to angiotensin 1
angiotensin 1 to angiotensin 2 by ACE
-causes blood vessels to narrow
15
Q
aldosterone produced by
A
adernal glands
main goal: keep sodium at expense of potassium
16
Q
sodium follows
A
aldosterone
17
Q
BTNP- brain type natriuretic peptide released in response
A
to increased fluid and blood pressure
main job: help body get rid of sodium so we can reduce fluid volume and decrease BP
18
Q
marker of congestive heart failure
A
BTNP
19
Q
hypernatremia causes
A
hyperaldosteronism
vomiting/ diarrhea
sweating
too much NaCl
diabetes insipidus
dehydration
20
Q
hyperaldosteronism also called
A
Conn’s syndrome
21
Q
hyponatremia causes
A
Vomiting and diarrhea
Hypo aldosterone
Severe burns -deletional
Kidney loss of sodium
Water excess
Syndrome of SIADH
diabetes
22
Q
hyponatremia osmolality
A
hypo osmolality
23
Q
increase or decrease of sodium depends on
A
how much sodium you lose compared to water
24
Q
SIADH
A
syndrome inappropriate anti-diuretic hormone
-too much ADH
25
loss of sodium in kidney specimen
urine
26
if Na >20
sodium being loss via the kidneys
-kidney disfunction
27
if Na < 20
something else is going on
28
specimen collection for sodium levels
serum or plasma (heparin)
no sodium heparin
29
sodium values detected via
glass ISE
direct ISE: no dilution required
indirect ISE: need dilution
-affected by increased lipids (centrifuge specimen first to clear them)
30
what is it called when sodium values affected by lipids
electrolyte exclusion effect
31
potassium found
intracellular -affect on specimen collection
quantity is 20x greater in RBC than ex.
32
where is potassium important
skeletal and cardiac muscle
33
range of potassium
3.5-5.3
>7 panic value
34
how is potassium regulated
kidneys
35
hyperkalemia causes
kidney issues
hypoaldosteronism - opposite
metabolic acidosis
bleed injury
drawing EDTA tube
K IV
36
hyperkalemia metabolic acidosis b/c
too much hydrogen and trys to pull hydrogen in and potassium also comes out
+ for +
water comes out and potassium also comes out when diluting glucose
37
hypokalemia causes
too much insulin- driving too much insulin into cell
hyperaldosteronism
increased GI or urinary loss
metabolic alkalosis
38
specimen integrity for potassium
NO hemolysis -false increase
no potassium draw after exercise- will leak out of cell
39
serum for potassium
serum has higher potassium
platlets give off small amount of potassium when they clot
increase in platelets-- slightly increase level of K
to correct draw plasma with heparin
40
can potassium specimen sit around for 5-6 hours
no
cells and serum have not been separated
RBC's will start to lyse
41
how is potassium measured
ISE with valamycin coated membrane
42
chloride found where
extracellular anion
hemolysis will not affect
43
chloride range
99-109
-helps maintain electroneutrality
44
chloride shift exchanges
bicarb in RBCs
passice
45
hypochloremia causes
same as sodium
but
metabolic alkalosis
-excess bicarb, so get rid of chloride
46
hyperchloremia causes
same as sodium
except
metabolic acidosis
-using bicarb to get back into balance, so keep chloride
increased in bromide concentration in blood- psycharatic meds
47
specimen collection for chloride
serum or plasma
ISE -silver chloride silver electrode
48
chlordie sweat test
no longer done
used to be done to test for cystic fibrosis (don't reabsorb chloride back into the skin)
only done on children
49
2nd most abundant cation in extracellular fluid
bicarb
-total CO2 made up mainly of bicarb
50
bicarb is a major
buffering system
-helps in acidosis by taking in hydrogen and making it into carbonic acid and eventually CO2 to get rid of it
51
bicarb normal value
22-26
52
how is bicarb regulated
kidneys
-either excreted or reabsorbed depending on body
increases or decreased related to metabolic acid base imbalance
53
calcium is needed for
bone development, muscle contractions, and coag cascade
98% found in bone
54
2 forms of calcium
bound
ionized- free form metabolically active
55
what is bound calcium too
albumin
dependent upon albumin levels
56
most responsible for control over calcium values
ionized
does not change day to day
-not dependent on albumin levels
57
parathyroid hormone -PTH
secreted by parathyroid
-behind thyroid
-regulated calcium via feedback loop- ionized calcium
58
when ionized Ca is low
PTH turned on
59
when ionized Ca is high
PTH turned off
60
3 effects on PTH regulated Ca
1. Activates bone resorption - osteoblast breaks down to released calcium
2. Helps kidneys keep calcium through reabsorption
3. Helps convert renal conversion of vitamin D to active form
61
where is vitamin D activated
kidney
62
what is the active form of vitamin D
1,25 dihydroxy vitamin D
63
PTH indirectly affects
phosphorus
Calcium and phosphorus inverse relationship
64
calcitonin
lowers calcium by inhibiting vitamin D with PTH???
65
magnesium is needed to release
PTH
-low magnesium = low PTH
66
hypercalcemia causes
hyperparathyroidism -remove gland
bone tumor -Ca in bones
paget's disease -abnormal breakdown
multiple myeloma
neonates -first 6 months increased Ca
67
if mom is hypercalcemia baby will
not have normal development of PTH
68
consequences of increased Ca
irregular heartbeat
mental confusion
formation of kidney stones
tetany
69
what enzyme is affect in increased Ca
ALP increased; bones
70
hypocalcemia causes
hypoalbuminemia
Low PTH
low vitamin D
low magnesium
menopause
71
hypoalbuinemia why in low Ca
much Ca is bound to albumin so total Ca are dependent on bound albumin
seen in decreased albumin
cause pseudo low values
-this is why to ionized Ca just bound
72
correction for low calcium
Corrected Ca= measured Ca + 0.8(4-serum albumin)
73
best measurement of calcium
ionized Ca
-collect anaerobically
sensitive to pH and temp
serum or heparin (can't use most anticoag)
74
normal calcium
8.5-10
75
where is Mg found
bone, some in cells, and small amount in the blood
ionized and bound form
76
cofactor for over 300 enzymatic reactions in body
magnesium
-helps in metabolism of CHO, lipids, and proteins
77
how is magnesium regulated
aldosterone and PTH
PTH helps in reabsorption
aldosterone acts the same way as it does on potassium
(aldosterone high, mg low)
78
normal mag levels
1.5-2.5
79
causes of hypo magnesium
long term diuretics
-cancer patients, alc. cirr
increased aldosterone
80
how to correlate Mg and Ca
if person has tetany and Ca look normal go to Mg
81
what is Mg associated with
vasospasms and sudden cardiac death
82
hyper magnesium causes
intake of laxatives and antacids
end stage liver disease- lead to cardiac arrest
83
specimen collection Mg
NO anticoag; block Mg
no hemolysis
84
in preg decreased levels of mg can lead to
pre-elcampsia
high bp, protein in urine , swelling in legs
giving mg can prevent the from going to eclampsia (seizures)
85
main buffering system for acid base balance in urine
phosphate
under control of PTH
86
if phosphate is too low
Hgb increased affinity to oxygen, won't want to give it up
-can affect hemoglobin affinity to oxygen
87
does phosphorus vary in the body
no!
diurnal variation
-high in morning and low at night
under the control of the kidney
88
collection for phosphate
serum or heparin
no anticoag
if taking growth hormones can't measure levels
89
why do we look at lactate levels
O2 deprivation, septic, or acidosis
90
what is lactate
by product that produces small amount of ATP when oxygen is low
91
lactate in normal glucose metabolism
glucose first goes to pyruvate then goes to acetyl Coa (under aerobic conditions)
(anerobic) pyruvate to lactate and leads to increases in NADPH
92
when there is too much lactate for the liver to handle -- you get a build up which is an indicator of
oxygen deprivation or sepsis
(think of anything that can cause hypoxia, no breathing, massive bleeding)
93
why in bacterial sepsis is there increased lactate
bacteria uses oxygen
buildup in metabolic acidosis and alcohol poisoning
94
normal lactate value
0.5-2
95
specimen collection lactate
no tourniquet - not longer than 2 minutes
gray tube on ice - prevent breakdown of glucose for 72 hours
96
anion gap
cations should = anions
(Na + K) - (Cl+ Bicarb)
w/o K= 8-16
with K= 10-20
don't do potassium anymore-- highest correlation with preanalytical error
97
increases in anion gap
DKA
OH- alcohol (alcohol breaks down to acids)
Instrument QC
-anion gap is qc for instrument error
-if screwed anion gap for lost for patients - instrument error
98
decreases in anion gap
low albumin
kidney/ liver failure
multiple myeloma- decrease in albumin, increase gamma globulin
99
osmolality
number of dissolved particles in solution
main particles for hypothalamus on and off
can turn on or off ADH
regulated aldosterone
100
normal osmol value
275-295
101
main drivers of osmolality
sodium
glucose
102
how to measure osmolality
freezing point depression
-also vapor pressure
use serum or urine
103
osmolality formula
2Na + (glucose/20) + (BUN/3 )
104
what is osmol gap
difference between measured and calculated
want it to be less than 10
105
when in osmol gap increased
acidosis and alcohol
#1 reason is alcohol
leads to alcohol testing on patient
106
ISE stands for
ion selective electrode
membrane makes it selective
107
ISE measures
free electrolytes
108
ISE type of analysis
potenime
109
internal solution in ISE
KCl
changes in voltage in zero current
