Electrolytes (exam 3) Flashcards
(135 cards)
1
Q
serum sodium usually reflects
A
water balance, not sodium itself
2
Q
sodium primarily determines
A
serum osmolality
3
Q
ways sodium stays balanced
A
vasopressin
thirst
natriuretic peptides
RAAS
4
Q
hyponatremia is dependent on
A
rapidity and degree of Na drop
5
Q
acute hyponatremia occurs in _____________ and chronic occurs in ____________
A
hours
days
6
Q
mild hyponatremia
A
125-134 mEq/L
nausea and malaise
7
Q
moderate hyponatremia
A
115-124 mEq/L
headache, lethargy, confusion
8
Q
severe hyponatremia
A
less than 114 mEq/L
delirium, seizure, coma and death
9
Q
isotonic hyponatremia causes
A
hypertriglyceridemia
hyperproteinemia
10
Q
isotonic hyponatremia treatment
A
none
use different assay
NOT REAL
11
Q
hypertonic hyponatremia
A
increased presence of effective osmoles other than sodium in the ECF
measured serum osmolality is high (over 280)
12
Q
causes of hypertonic hyponatremia
A
severe hyperglycemia
mannitol
dilution of existing sodium
13
Q
treatment of hypertonic hyponatremia
A
treat underlying cause
remove substances contributing to osmolar gap
14
Q
hypertonic hyponatremia caused by hyperglycemia causes a
A
decrease in sodium
15
Q
corrected na =
A
measured Na + (glucose level-100)0.016
16
Q
hypovolemic hypotonic hyponatremia
A
secondary to a decrease or depleted volume status
UOsm > 450
17
Q
hypovolemic hypotonic hyponatremia from extra renal losses have a UNa of _________________. examples include ______________
A
less than 20 mEq/L
vomiting/diarrhea
excessive sweating
burns
18
Q
hypovolemic hypotonic hyponatremia from renal losses have a UNa of _____________. examples include _____________
A
over 20 mEq/L
diuretics and adrenal insufficiency
19
Q
treatment for hypovolemic hypotonic hyponatremia
A
does not require rapid correction
replace volume with isotonic saline or balanced crystalloid
discontinue diuretic
20
Q
hypervolemic hypotonic hyponatremia
A
decreased effective arterial blood volume
UOsm > 100 and UNa < 20 mEq/L
21
Q
hypervolemic hypotonic hyponatremia treatment
A
fluid and sodium restriction
loop diuretics
correction of underlying disease
22
Q
what can be used to treat hypervolemic hypotonic hyponatremia that are controversial?
A
tolvaptan and conivaptan (vasopressin receptor antagonists)
23
Q
-vaptans have a black box warning for __________ so limit therapy to ________
A
hepatotoxicity
30 days
24
Q
euvolemic hypotonic hyponatremia
A
total sodium content is consistent but total body water increases
25
euvolemic hypotonic hyponatremia is most commonly secondary to
persistent ADH secretion and it can be drug induced
26
euvolemic hypotonic hyponatremia when UOsm > 100 and UNa > 20
hypothyroidism
hypocortisolism
kidney failure
SIADH
27
euvolemic hypotonic hyponatremia when UOsm < 100 and UNa < 20
primary polydipsia
low solute intake
28
SIADH leads to increased secretion and activity of ___________ which results in increased ________________. This means there is an increase in _______________ and decrease in ______________.
ADH
water retention
blood volume
serum osmolarity
29
SIADH causes that increase ADH release
nicotine
barbiturates
tricyclines
vinca alkaloids
carboplatin and cisplatin
haloperidol
thioridazine
opioids
MAOIs
bromocriptine
30
SIADH causes that increase ADH sensitivity
APAP
NSAIDs
carbamazepine
lamotrigine
31
SIADH causes that are from malignancy
lung
pancreatic
duodenal
32
SIADH causes from respiratory disorders
pneumonia
TB
ARDS
33
SIADH causes from CNS disorders
hemorrhage
trauma/stroke
meningitis
34
SIADH causes with unknown mechanisms
omeprazole
moxifloxacin
ACEIs
SSRIs
35
first line treatment for euvolemic hypotonic hyponatremia
fluid restriction
correct underlying disease
36
second line treatment for euvolemic hypotonic hyponatremia
urea (salt tabs)
democlocycline
vaptans
37
what is second line for euvolemic hypotonic hyponatremia but controversial?
lithium
38
what to use for sodium repletion
hypertonic saline (2% or 3% NaCl)
39
when there are moderate symptoms, during sodium repletion you can omit the
bolus
40
sodium repletion goals for asymptomatic acute hyponatremia
increase serum sodium by 6-8 mEq/L in 24 hours
41
sodium repletion goals for chronic hyponatremia
increase serum sodium by 6-8 mEq/L in 24 hours
42
sodium repletion goals for acute hyponatremia
increase serum sodium by 4-6 mEq/L in 6 hours then slow correction to steady rate over 24 hours
43
most cases of ODS occur when Na is raised by more than __________________ within 24 hours or ______________ in 48 hours so limit correction to no more than __________________
10-12 mEq/L
18 mEq/L
8 mEq/L in 24 hrs
44
osmotic demyelination syndrome (ODS)
when sodium is corrected to fast, ECF osmolality increases
water shifts out of brain cells
brain shrinks and loses volume
irreversible damage to central pons and extrapontine structures
45
ODS can result in
hyperreflexia
para/quadparesis
parkinsonism
locked-in syndrome
death
46
early symptoms of hypernatremia
lethargy
weakness
irritability
47
late symptoms of hypernatremia
twitching
seizures
coma
intracerebral hemorrhage
death
48
hypernatremia is common in those with
impaired thirst response and those without access to water
49
causes of hypovolemic hypernatremia
impaired thirst
diarrhea
osmotic diuresis
50
causes of euvolemic hypernatremia
diabetes insipidus
fever
extensive burns
mechanical ventilation
51
causes of hypervolemic hypernatremia
excessive Na administration including:
hypertonic sodium bicarb
hypertonic dialysis
cushings
salt tabs
hyperaldosteronism
52
hypovolemic hypernatremia treatment
1. restore intravascular volume with 0.9% NS
2. correct the water deficit with 0.45% NaCl or D5W
53
goal for correction of hypovolemic hypernatremia
initially reduce Na by 0.5-1 mEq/L/hr
DO NOT REDUCE BY MORE THAN 10-12 mEq/day
54
nephrogenic diabetes insipidus (euvolemic)
decreased kidney response to vasopressin
55
central diabetes insipidus (euvolemic)
decreased AVP secretion
56
nephrogenic diabetes insipidus (euvolemic) treatment
thiazide diuretic and sodium restriction, indomethacin, amiloride
57
central diabetes insipidus (euvolemic) treatment
vasopressin replacement (desmopressin)
titrate to 1.5-2L daily urine volume
58
hypervolemic hypernatremia treatment
diuretics
free water replacemet
59
hypokalemia causes
poor dietary intake
excessive loss (diuretics, GI)
intracellular shifts (inc pH, insulin, B2 agonists)
medications
rapid refeeding syndrome
hypomagnesemia
60
what causes transcellular shifts that can lead to hypokalemia?
B2 agonists
theophylline/caffeine
levothyroxine
insulin
verapamil
decongestants
61
what causes enhanced renal excretion that can lead to hypokalemia?
diuretics
penicillins
mineralcorticoids
aminoglycosides
amphotericin B
62
what causes enhanced fecal elimination that can lead to hypokalemia?
laxatives
sodium polysterene/sulfonate
sorbitol
chemotherapy
patiromer
63
what replacement is preferred in hypokalemia treatment?
oral
64
what is the most effective treatment for hypokalemia and why
chloride salts
treats the most common causes of hypokalemia
65
_______________ is necessary if there is severe hypokalemia (<2.5), symptomatic, or unable to tolerate oral
IV replacement
66
considerations when using IV replacement for hypokalemia
EKG monitoring is necessary if infusing > 10 mEq/hr
67
mild hyperkalemia
5.1-5.9 mEq/L
68
moderate hyperkalemia
6-7 mEq/L
69
severe hyperkalemia
over 7 mEq/L
70
causes of hyperkalemia
overcorrection of hypokalemia
renal failure
extracellular shifts
decreased aldosterone
71
medications that can cause hyperkalemia
ACEIs
ARBs
K sparing diuretics
NSAIDs
heparins
Bactrim
72
symptoms of hyperkalemia
muscle weakness/paralysis
abnormal cardiac conduction (peaked T waves, widened QRS, V-fib, asystole)
73
__________________ is a life threatening emergency and requires immediate treatment
EKG changes
74
what to do when there are EKG changes
1. stabilize the cardiac tissue and antagonize cardiac effects
2. redistribute K from ECF to ICF
3. eliminate excess K from the body if needed
75
what is used to stabilize the cardiac tissue and antagonize cardiac effects?
calcium (chloride or gluconate)
76
what form of calcium is preferred in emergency situations?
why?
calcium chloride
faster dissociation, provides 3x more calcium
77
drawback from calcium chloride
can cause tissue necrosis if administered in small vein or too fast
78
what can be used to redistribute K from ECF to ICF
insulin +/- dextrose
albuterol
sodium bicarbonate
79
undesirable effects of albuterol
tachycardia
80
albuterol and insulin both sitimulate
the Na/K/ATPase pump
81
sodium bicarbonate is most effective if the patient has
metabolic acidosis
82
sodium bicarbonate can lead to
alkalemia
Na overload
83
sodium bicarbonate is not as effective in
CKD patients
84
what can be used to eliminate excess K from the body if needed
sodium zirconium cyclosilicate (Lokelma)
sodium polystyrene sulfonate (Kayexalate)
Patiromer (Veltassa)
increase renal elimination
85
sodium zirconium cyclosilicate (Lokelma)
average decrease of 1 mEq/L for a 10 g dose
can cause edema
administer other meds 2 hours before or after
86
sodium polystyrene sulfonate (Kayexalate) fell out of favor due to
bowel necrosis and ischemia
87
Patiromer (Veltassa)
exchanges Ca for K in intestine and inc fecal elimination
can cause constipation, hypomagnesemia and diarrhea
88
how to increase renal elimination
loop diuretics
hemodialysis
89
what causes hypomagnesemia in the GI tract?
PPIs (reduced absorption)
excessive laxative use (increased loss)
90
91
what causes hypomagnesemia in the renal system?
amphotericin B
aminoglycosides
cyclosporine/tacrolimus
loop diuretics
digoxin
cisplatin
foscarnet
92
hypomagnesemia signs and symptoms
tetany, twitching, convulsions, ckvostek's sign, trousseau's
arrhythmias
sudden cardiac death
93
torsades de pointes can be seen with
hypokalemia
hypomagnesemia
prolonged QT interval
94
how to treat asymptomatic hypomagnesemia?
how long does it take to replete?
oral supplements
3-4 days
95
how to treat severe or symptomatic hypomagnesemia?
slow IV magnesium sulfate
96
if magnesium is less than 1 mEq/L and the patient is asymptomatic, treat with
4-6 grams magnesium sulfate IV divided over 12-24hrs (max infusion rate 1g/hr)
97
if magnesium is less than 1 mEq/L and the patient is experiencing life threatening seizures or torsades, treat with
2 g magnesium sulfate IV push over 1-2 minutes if pulseless
98
hypermagnesemia criteria
hypo?
over 4 mEq/L
under 1.4 mEq/L
99
causes of hypermagnesemia
renal failure
excessive repletion
100
symptoms of hypermagnesemia
sedation
hyporeflexia
muscle paralysis
bradycardia
hypotension
heart block
101
treatment of hypermagnesemia if asymptomatic
administer normal saline and loop diuretics to promote elimination
reduce intake
102
treatment of hypermagnesemia if symptomatic
dialysis***
IV calcium to correct neuromuscular/cardiac abnormalities
loop diuretics
103
corrected ca =
0.8(4- albumin) + measured calcium
104
most common cause of hypocalcemia
hypoparathyroidism
vitamin D deficiency
105
other causes of hypocalcemia
excessive blood product administration
continuous renal replacement therapy
hypomagnesemia
tumor lysis syndrome
106
acute symptoms of hypocalcemia
muscle cramps
tetany
QT prolongation
arrhythmias
107
chronic symptoms of hypocalcemia
depression
confusion
hallucinations
seizures
108
step 1 management of hypocalcemia
check corrected calcium or get ionized calcium level
determine if its real!
109
step 2 management of hypocalcemia
due to hypoalbuminemia
110
if corrected/ionized calcium is higher than 8.5 mg/dl
do nothing!
111
if corrected/ionized calcium is lower than 8.5 mg/dl
proceed to step 3
112
step 3 management of hypocalcemia
determine if symptomatic and treat accordingly
113
how to treat when mild-moderate asymptomatic hypocalcemia (ionized 4-4.49 mg/dl)
oral supplementation
may administer 1-2 grams IV calcium gluconate
114
how to treat when acute severe, symptomatic treatment (ionized <4 mg/dl)
bolus 100-300mg elemental Ca IV over 10 mins
continuous infusion of calcium gluconate 5-20 mg/kg/hr
115
which form of calcium is preferred peripheral?
central?
calcium gluconate
calcium chloride
116
do not mix calcium with ___________________ because it can cause possible precipitation
bicarbonate or phosphate containing solutions
117
what to monitor when treating hypocalcemia
serum calcium every 4-6 hours during infusion
118
most common causes of hypercalcemia
cancer
primary hyperparathyroidism
119
medications that cause hypercalcemia
thiazides
lithium
excessive vitamin D or calcium
theophylline
120
symptoms of hypercalcemia range from
GI
Renal
CNS
cardiac
121
first line for hypercalcemic crisis/severe hypercalcemia (>12mg/dl)
increase urinary excretion with volume expansion and loop diuretics
122
alternatives for hypercalcemic crisis/severe hypercalcemia (>12mg/dl)
calcitonin
hemodialysis
corticosteroids
123
last line for hypercalcemic crisis/severe hypercalcemia (>12mg/dl)
gallium nitrate
124
treatment for mild to moderate hypercalcemia
correction of underlying disorders
bisphosphonates
125
causes of hypophosphatemia
decreased GI absorption
increased renal elimination
alcoholism, malnutrition, rapid refeeding
126
symptoms of hypophosphatemia
metabolic encephalopathy
neuropsychiatric disturbances
respiratory failure
difficulty weaning from mechanical ventilation
muscular weakness
cardiac arrhythmias
127
treatment for mild-moderate hypophosphatemia
oral phosphate salts
goal to correct over 7-10 days
128
ADR of oral phosphate salts
osmotic diarrhea
129
treatment for severe hypophosphatemia (<1.5 mg/dl)
IV therapy
15-30 mmol phos in 250ml of D5W or 0.9% NaCl over 3-6 hours
can use weight based dose of 0.32-0.64 mmol/kg
130
(severe hypophosphatemia) if K < 3.5 mEq/L then use
K-phos
131
(severe hypophosphatemia) if K > 3.5 mEq/L then use
Na-phos
132
if infusion of K-phos or Na-phos is given faster there is a higher risk of
calcium phosphate product deposition
133
treatment for non-emergent hyperphosphatemia
decrease dietary intake
decrease dietary absorption using phosphate binders
134
examples of phosphate binders
antacids containing divalent or trivalent cations
sevelemer
calcium acetate
135
treatment for severe symptomatic hyperphosphatemia presenting with hypocalcemia and tetany
stop all exogenous phosphorus
Bolus 100-300 mg elemental Ca IV 5-10 min
consider hemodialysis
