electrolyte disorders Flashcards
(128 cards)
1
Q
causes of hyperkalemia
A
cellular redistribution from the intracellular to the extracellular compartment
K++ retention
impaired K++ excretion
tissue breakdown
2
Q
Hyperkalemia commonly associated with what
A
renal failure
ACE inh
hyporeninemic hypoaldosteronism
cell death
metabolic acidosis
3
Q
severe hyperkalemia can result in what
A
dysrhythmias and cardiac arrest
4
Q
what can cause spurious hyperkalemia
A
thrombocytosis and hemolysis
5
Q
hypoaldosteroism and metabolic acidosis commonly assoc with what
A
hyperkalemia
6
Q
earliest ECG manisfestation of hyperkalemia is what
(over 6.5)
A
peaking of T waves
7
Q
ECG changes in severe hyperkalemia(over 7)
A
P wave flattening, PR interval prolongation, QRS widening
8
Q
what to give in severe hyperkalemia with heart effects
A
calcium gluconate IV to antagonize effects of heart.
9
Q
what can you give to drive K++ back into the intracellular compartment;
good/bad
A
sodium bicarb, glucose, insulin;
rapid onset but duration short
10
Q
what to give to remove K++ from the body
A
kayexalate
last resort: hemodialysis
11
Q
neurologic symptoms of hyperkalemia
A
numbness, tingling, weakness, flaccid paralysis
12
Q
labs for hyperkalemia
A
serum K++ over 5
urine K++, Cr, osmolality reveal decreased fractional excretion of K++
13
Q
EKG when K++ is 8-10
A
sine wave pattern with cardiac arrest
14
Q
cellular redistribution from the intracellular to the extracellular compartment
K++ retention
impaired K++ excretion
tissue breakdown
A
causes of hyperkalemia
15
Q
renal failure
ACE inh
hyporeninemic hypoaldosteronism
cell death
metabolic acidosis
A
Hyperkalemia commonly associated with what
16
Q
P wave flattening, PR interval prolongation, QRS widening
A
ECG changes in severe hyperkalemia(over 7)
17
Q
numbness, tingling, weakness, flaccid paralysis
A
neurologic symptoms of hyperkalemia
18
Q
serum K++ over 5
urine K++, Cr, osmolality reveal decreased fractional excretion of K++
A
labs for hyperkalemia
19
Q
pnemonic for hyperkalemia tx
A
C BIG BK
calcium gluconate
bicarb and/or insulin and glucose to temporarily shift K++ back into cells
B agonists to promote celluar reuptake of K++
Kayexalte to remove K++ from body
20
Q
causes of hypokalemia
A
shift of K++ into intracellular compartment or from K++ losses of extrarenal or renal origin
most commonly occurs with diuretics, renal tubular acidosis, GI losses, hypomagnesemia, polyuria
21
Q
vent arrhythmias, MI, ileus, constipation, rhabdomyolysis
A
think hypokalemia
22
Q
ECG in hypokalemia
A
flattened or inverted T waves, prominent U waves, ST depression, ventricular ectopy
23
Q
most helpful tests for causal workup of hypokalemia
A
blood acid-base parameters, urinary K++ and Cl levels
24
Q
how does hypokalemia affect the heart
A
it potentiates the effects of cardiac glycosides on myocardial conduction and may lead to dig intoxication
25
cardiovascular manisfestations of hypokalemia
ventricular arrhythmias, hypoTN, cardiac arrest
26
neuromuscular manisfestations of hypokalemia
malaise, skeletal mm weakness, cramps, smooth mm involvement leading to ileus and constipation
27
polyuria, nocturia, hyperglycemia, rhabdomyolysis, ileus, cramps or weakness, hyporeflexia, ascending paralysis
hypokalemia
28
how to distinguish renal from GI losses on hypokalemia
24 hr or spot urine K++ test
29
If hypokalemia is not responding to K++ repletion, then what
check magnesium levels
30
shift of K++ into intracellular compartment or from K++ losses of extrarenal or renal origin
most commonly occurs with diuretics, renal tubular acidosis, GI losses, hypomagnesemia, polyuria
causes of hypokalemia
31
flattened or inverted T waves, prominent U waves, ST depression, ventricular ectopy
ECG in hypokalemia
32
it potentiates the effects of cardiac glycosides on myocardial conduction and may lead to dig intoxication
how does hypokalemia affect the heart
33
ventricular arrhythmias, hypoTN, cardiac arrest
cardiovascular manisfestations of hypokalemia
34
malaise, skeletal mm weakness, cramps, smooth mm involvement leading to ileus and constipation
neuromuscular manisfestations of hypokalemia
35
relationship between PTH, Ca, Phosphorus
PTH and Ca same, phosphorus different
36
hospitalized pt with malignancy
think hypercalcemia
37
anorexia, nausea, constipation, polyuria, polydipsia, consciousness level, inravascular volume depletion
hypercalcemia
38
24 hr urine calcium levels mean what
elevated: cancer or hyperparathyroidism. decreased: hyperparathyroidism
39
worst thing hypocalcemia can do
complete cardio collapse
40
psoriasis, dry skin, perioral numbness
CV signs: wheezing, bradycardia, crackles, S3
hypocalcemia signs
41
common causes of disorders of calcium and phosphorus
PTH d/o, chronic renal failure, malignancy
42
vitamin D intoxication, hyperparathyroidism, sarcoidosis
other causes of hypercalcemia
43
which calcium disorder is more common?
found in who?
hypocalcemia
critically ill pts
44
hypercalcemia
s/s
anorexia, nausea, constipation, polyuria, polydipsia, consciousness level, inravascular volume depletion
45
common causes of hypocalcemia
chr disease(like CKD) or hypoparathyroidism
46
what is trosseau's sign
carpel tunnel spasm after BP cuff applied for 3 min. hypocalcemia
47
what is chvostek's sign
spasm of facial muscle after tapping facial nn. hypocalcemia
48
severe hypocalcemia results in what
complete cardiovascular collapse
severe manisfestations: syncope and angina
49
brittle nails, pruritis, mm cramps, SOB, n/t in extremities
sx of hypocalcemia
50
hypocalcemia signs
psoriasis, dry skin, perioral numbness
CV signs: wheezing, bradycardia, crackles, S3
51
neuro findings in hypocalcemia
trousseau, chvostek, confusion, dementia, seizure, irritability
52
cramps and tetany after a thyroidectomy
hypocalcemia
53
labs for hypocalcemia
ionized Ca and PTH
54
corrected calcium formula
measured total calcium + [0.8 x (4-albumin)]
55
normal calcium levels
8.5 to 10.2
56
tests to order for hypercalcemia
corrected Ca
CXR to look for pulm mass
UA for hematuria- RCC
ESR
24 hr urine
57
hypercalcemia tx
isotonic saline for volume repletion
loop if hypervolemic after this
bisphosphonates for severe cases
58
vitamin D def, respiratory alkalosis, burns, hyperPTH
common causes of hypophosphatemia
59
hyperphosphatemia commonly secondary to what
CKD
60
hypophosphatemia commonly secondary to what
diminished supply or absorption, increased urinary losses or redistribution
61
severe hypophosphatemia may lead to what
rhabdo, paresthesia, encephalopathy
62
phosphate binders
calcium carbonate tablets
63
normal phosphate levels
2.5 to 4.5
64
normal magnesium levels
1.5 to 2.5
65
sx of hypermagnesemia
usually asymptomatic except in CKD given Mg products such as laxatives or antacids
decreased DTR, mm weakness, N/V, resp depression, then cardiac arrest follows
66
ECG findings in hypermagnesemia
widened QRS complex, prolonged PR interval, prolonged Q-T interval
67
bleeding and clotting times increased
think hypermagnesemia
68
tx of hypermagenesemia
calcium gluconate, lasix, dialysis
69
hypokalemia, hypocalcemia, hypocalciuria assoc with what
hypomag
70
most magnesium is stored where
bones and muscles
71
tx of hypomagnesemia
oral magnesium oxide for chronic cases
severe symptomatic: mag sulfate sol'n IV 7 days(1 gm then 6 days over 1 L in 24 hrs); or IM 4 doses
72
when does hypomag appear
when total body stores are severely depleted; usually from diminished intake and impaired absorption
73
what is hypomag commonly associated with
chronic alcoholism
chronic diarrhea
hypoPTH
hyperaldosteronism
diuretic therapy
osmotic diuresis
nutritional deficiencies
long term use of PPI
74
S/S of hypomag
tetany, N/V, lethargy, anorexia, weakness, seizures, weakness
75
labs and EKG for hypomag
hypokalemia, hypocalcemia, hypocalciuria
EKG: prolonged PR and QT interval or widening of QRS
76
hypokalemia and hyperkalemia levels
under 3.5 mEq/L
over 5.0 mEq/L
77
flaccid paralysis and ascending paralysis
hyperkalemia
hypokalemia
78
sodium bicarb, glucose, and insulin can do what
drive K++ cells intracellularly
79
hyporeflexia can be what
hyperreflexia
hyporeflexia: hypokalemia
hyperreflexia: hypernatremia
80
hypoaldosteronism can be what
hyperaldosteronism
hyperkalemia
hypomagnesium
81
hyperPTH
hypoPTH
Hyper: hypophosphatemia and hypercalcemia
hypo: hypocalcemia and hypomagnesium
82
calcium gluconate for what
severe hyperkalemia
hypermagnesium
83
rhabdomysis can appear in what
hypokalemia
hypophosphatemia
84
when to get a corrected calcium and an ionized calcium
corrected in hypercalcemia
and ionized in hypocalcemia
85
hypernatremia level if what
over 145 mEq/L
86
low urine Na and polyuria
DI
87
what to worry about in hypernatremia
brain cell shrinkage and DI
88
Na greater than 200
do dialysis
89
what is the most common electrolyte disorder seen in general hospital population secondary to use of hypotonic fluid administration
hyponatremia
90
hypovolemia and cheyne stokes respirations
hyponatremia
91
hypernatremia occurs in who
elderly and may occur in infants with diarrhea
92
neurologic manifestations of hypernatremia
thirst(from hypertonicity), restlessness, irritability, disorientation, lethargy, delirium, convulsions, coma
93
thirst(from hypertonicity), restlessness, irritability, disorientation, lethargy, delirium, convulsions, coma
neurologic manifestations of hypernatremia
94
non neurological symptoms of hypernatremia
dry mouth, dry mucous membranes, lack of tears, decreased salivation, flushed skin, tachycardia, hypoTN, fever, oliguria, anuria, hyperventilation, lethargy, HYPERREFLEXIA
95
6 hypernatremia causes pnemonic
Diuresis
dehydration
DI
docs(iatrogenic)
diarrhea
disease(kidney, sickle cell)
96
dry mouth, dry mucous membranes, lack of tears, decreased salivation, flushed skin, tachycardia, hypoTN, fever, oliguria, anuria, hyperventilation, lethargy, hyperreflexia
non neurological symptoms of hypernatremia
97
urine sodium decreased/elevated vs concentrated/diluted
decreased if hypernatremia is due to extrarenal losses and elevated if due to renal losses or sodium excess.
Concentrated with extrarenal losses and diluted with DI
98
antidiuretic stimulation and DI
it does not increase urine osmolality in nephrogenic DI
99
how to indicate a hyperosmolar coma
elevated serum glucose
decreased UO
increased urine osmomality
100
urine osmolality under 100
and 100-300
central DI
nephrogenic DI
101
hypernatremia treatment
\* preferred route
\*unstable vital signs
\* hypovolemia present
\*dialysis
\*caution in what
free water orally is preferred, can also do IV or SQ 5% dextrose solution
unstable: do isotonic 0.9% NaCl
treat hypovolemia first(isotonic saline or LR) then the hypernatremia
dialysis if sodium greater than 200 mEg/L
caution because rapid correction can cause pulmonary or cerebral edema, especially in pts with DM
102
hyponatremia levels
sodium less than 130-135
103
hyponatremia usually due to what
increased ADH
104
hyponatremia with hypervolemia occurs when
in the setting of CHF, nephrotic syndrome, renal failure, hepatic cirrhosis
105
hyponatremia with euvolemia occurs when
with hypothyroidism, glucocorticoid excess, SIADH
106
SIADH
The syndrome of inappropriate antidiuretic hormone hypersecretion (SIADH) is characterized by excessive release of antidiuretic hormone (ADH or vasopressin) from the posterior pituitary gland or another source. The result is HYPOTONIC hyponatremia and sometimes fluid overload.
107
if you suspect SIADH...
CT to rule out CNS d/o and CXR to rule out lung pathology
108
demeclocycline for what?
risks?
- for chr hyponatremia unresponsive to fluid restriction; to induce nephrogenic DI.
- may cause neprotoxicity in pts with cirrhosis
109
ADH from what
pituitary hormone
110
tx for neurogenic(central) DI
what to do for mild disease
nephrogenic DM
diet
- parenteral or intranasal desmopressin
- diuretics, chlorpropamide, carbamazepine
- HCTZ, amiloride diuretics, indomethacin
- limited salt and protein
111
SIADH found in what diseases
It is usually found in patients diagnosed with small-cell carcinoma of the lung, pneumonia, brain tumors, head trauma, strokes, meningitis, and encephalitis.
112
SIADH
urine osmolality
urine sodium
osmolality greater than 100
sodium greater than 40
113
hyponatremia clinical symptoms
lethargy, disorientation, muscle cramps, anorexia, hiccups, N/V, seizures
114
signs of hyponatremia
HYPOreflexia, orthostatic hypoTN, cheyne stokes respirations, coma, stupor, delirium, agitation
115
lethargy, disorientation, muscle cramps, anorexia, hiccups, N/V, seizures
hyponatremia clinical symptoms
116
HYPOreflexia, orthostatic hypoTN, cheyne stokes respirations, coma, stupor, delirium, agitation
signs of hyponatremia
117
what can progress to seizures, coma, or brainstem herniation
hyponatremia
118
formula for serum osmolality
(2 x serum Na) + (BUN/2.8) + (glucose/18)
119
dangers of correcting hyponatremia too rapidly
central pontine myelinolysis or osmotic demyeination
120
order what tests if SIADH suspected
CT and CXR
121
hyponatremia treatment in
1) hypervolemic & euvolemic
2) hypovolemic
1) water restriction +/- diuretics
2) Normal saline
122
chronic hyponatremia tx
1) rate
2) unresponsive to fluid restriction
3) euvolemic or hypervolemic hyponatremia
1) over 72 hr duration with \<8 mEq/L/day
2) demeclocycline
3) vasopressin antagonists(conivaptan)
123
causes of DI
1) neurogenic
2) nephrogenic
3) acquired
Neurogenic: deficient secretion of ADH from pituitary
nephrogenic: kidneys unresponsive to normal vasopressin levels, inherited X linked trait,
acquired from lithium therapy, HYPOkalemia, HYPERcalcemia, or renal disease
124
main symptoms of DI
polyuria(50-60 mL/kg/day), nocturia, polydipsia,
maybe seizures
125
how to differentiate neurogenic and nephrogenic DI
Water deprivation and desmopresin testing(DDAVP):
NEUROGENIC(central) DI: dec urine output and increased urine osmolality
if little or no change in urine osmolality, it is most likely NEPHROGENIC DI
126
urine osmolality less than 250 mOsm/kg
despite hyperkalemia
it is NEPHROgenic DI
127
tx for central DI and nephrogenic DI
central: DDAVP
nephrogenic: salt restriction and water intake, thiazide diuretics
128
labs in volume depletion
hemocrit and serum albumin increased
urinary sodium decreases
urea increases (secondary to urine stasis in nephron) but little change in serum Cr
