The flashcards below were created by user
on FreezingBlue Flashcards.
normal potassium levels
3.5 -5.0 mEq/L
clinical manifestation of moderate to severe hypokalemia (include AP)
- weakness, myalgias, bradycardia
- flattening of T wave and prominet U wave
AP: lowers baseline, repoolarization faster, hyperpolarization?
treatment for asymptomatic hypokalemia
- oral potassium
- increase potassium intake
- maybe: K sparing diuretic (mild hypokalemai, but need diuretic)
treatment for symptomatic hypokalemia
IV 10-20 mEq/L K diluted in 100 mL NSS given over 1 hr
monitoring for hypokalemia (severe and mild)
- severe - monitor q4-6h with IV
- mild - with oral every 2 weeks
if no inc in K in 72 hrs, check Mg
electrolyte disorder assoicated with Addison's disease
electrolyte disorder associated with adrenal insufficiency
drugs associated with hyperkalemia (7)
- K-sparing (spironolacton, triamteren/amiloride)
clinical manifestation of moderate to severe hyperkalemia (include AP)
- more effect on the heart
- peaked T waves
- wider QRS
- can lead to v. fib and asystole
what happens to repol and hyperpol in hypokalemia
- repol - quicker
- hyperpol - slower
what happens to repol and hyperpol in hyperkalemia
- repol - slower
- hyperpol - quicker
treatment of moderate to severe hyperkalemia
Ca slow push over 5 min, insulin/dextrose, furosemide 20-40 mg IV
1. antagonize cardiac effects: 1 g Ca gluconate or chloride slow push over 5 min
2. push K back into cell: insulin/dextrose (first line); albuterol (second line) [DON'T GIVE EPI]; sodium bicarbonate (3rd line)
3. excrete excess K: furosemide 20-40 mg IV
treatment for chronic hyperkalemia
- diuretics - oral furosemide
- fludrocortisone - takes several days to work
normal magnesium levels
1.7 - 2.3 mg/dL
alcoholism is associated with which electrolyte disorder?
What is a positive Chvostek's indicative of?
What is a positive Trousseau's indicative of?
treatment for asymptomatic hypomagnesemia?
- oral magnesium supplements
- Mg oxide = most Mg
- Mg gluconate = least Mg
lactate and chloride = least diarrhea
treatment for symptomatic hypomagnesemia
Mg sulfate 2-4 g IV over 2-4 hrs [NO PUSH]
clinical presentation of hypermagnesemia
- loss of deep-tendon reflexes
- CNS depression
- resp muscle paralysis and dysrhythmias
- heart block b/c vents can't contract
which electrolyte disorder is most common in renal failure?
treatment of symptomatic hypermagnesemia
- 1. Ca chloride or gluconate 1 g IV slow push over 5 min
- 2. forced diuresis with normal saline and IV furosemide
- can use shock and supportive care in life-threatening situations
normal osmolality levels
normal sodium levels
what does ANP do? and when is it released?
atrial natriuretic peptide - regulates Na excretion independent of water
released when it is stretch b/c of too much blood volume in the atria
Steps to approaching sodium disorders
- 1. Check serum Na concentration (-natremic)
- 2. Check serum osmolality (-tonic)
- 3. Check fluid status (-volemic)
- 4. Check urine sodium and urine osmolaltiy (to determine cause of Na disorder)
Lab abnormalities present in hypovolemia
- increased BUN:Scr ratio ( >20:1)
- increased hematocit
correcting hyponatremia too quickly will cause:
osmotic demyelination syndrome
hyponatremia is usually associated with:
impaired water excretion
excessive sodium loss is usually because of:
thiazide diuretics in elderly women
which electrolyte disorder is technically not possible?
what is hypertonic hyponatremia caused by?
increased number of solutes other than Na in the ECF
What are the risk factors for hypovolemic hypotonic hyponatremia
- low body mass (dec in TBW)
- concurrent meds that impair water excretion
SIADH can cause what electrolyte disorder?
isovolemic hypotonic hyponatremia
clinical presentation of hyponatremia
mental status changes
treatment of symptomatic hypovolemic hypotonic hyponatremia?
treatment of symptomatic hypervolemic hypotonic hyponatremia?
treament asymptomatic hypervolemic hypotonic hyponatremia?
- restrict fluid intake
- inc Na intake
rate of saline infusion in acute symptomatic hyponatremia
1.5 - 2 mEq/L/hr (12 mEq/L/day)
rate of saline infusion in chronic symptomatic hyponatremia?
1 mEq/L/hr (12 mEq/L/day)
rate of saline infusion in chronic asymptomatic hyponatremia?
treatment for symptomatic isovolemic hypotonic hyponatremia?
- 3% saline
- ADH antagonist - conivaptan or tolvaptan (LD: 20 mg IV infused over 30 min; MD: 20-40 mg IV infusion over 24 hrs for 1-3 days)
treatment for asymptomatic isovolemic hypotonic hyponatremia?
- demecocycline (chronic SIADH) - slow onset
- initially: 900-1200 mg, then dec: 600-900 mg qd
what is demecocycline used for?
isovolemic hypotonic hyponatremia (SIADH)
What is SIADH associated with?
isovolemic hypotonic hyponatremia
What condition is a counterpart of SIADH? What medications can cause this?
Nephrogenic diabetes insipidus
lithium, demeclocycline, cidofovir, foscarnet
Which diuretics can cause hypovolemic hypernatremia?
What can cause hyperolemic hypernatremia?
- sodium overload
- mineralcorticoid excess
what electrolyte disorder is diabetes insipidus associated with? And what are the two types?
- central diabetes insipidus
- nephrogenic diabetes insipidus
What is central DI associated with?
a lack of ADH secretion due to head trauma, surgy, or cancer
what is nephrogenic DI associated with?
lack of sensitivity of ADH (opposite of SIADH) caused by drugs such as demeclocycline which is used to treat SIADH
what electrolyte disorders can cause SIADH?
when do you see the onset of polyuria in DI?
- central - sudden onset
- nephrogenic - gradual onset
how do you decide what kind of DI it is?
- water deprivation test:
- 1. restrict water for 8-12 hours
- 2. give desmopressin
- 3. measure the osm before and after dDAVP given
- if central will see a dec in urine outpus
- if nephrogenic will not see a change
How do yo treat hypovolemic hypernatremia?
- replace 50% of water deficit in 24 hrs
- replace rest of 50% deficit over next 1-2 days
how do you treat central DI?
- dDAVP (desmopressin) 10 mcg intranasally QD - BID
- chlorpropamide 125 - 250 mg PO QD
- carbamazepin 100 mg - 300 mg PO QD
- clofibrate 500 po QID
how do you treat nephrogenic DI?
- sodium restriction
- HCTZ 25 mg po q12-24h
- amiloride 5-10 mg po qd (for Li induced)
- --indomethacin 50 mg q8-12h
- --tometin 150 mg q6-8h
how do you treat hypervolemic hypernatremia?
- IV furosemide 20-40 mg