Fluids and Electrolyte Therapy Flashcards
as we age do you gain or lose water content?
Lose
What has a bigger fluid distribution, intracellular or extracellular?
intracellular
What are the primary intra cellular ions?
K and Mg and proteins and phosphates
What are the primary extracellular ions?
Na, Cl, HCO3
Why are serum levels misleading to the whole body store of electrolytes?
because the serum only contains 5% of the total body weight and only 10% of the total body water
what are the three types of extracellular fluid?
intravascular/plasma, interstitial/extavascular/extracellular, nonfunctional extracellular fluid from 3rd spacing
how can edema be one sided and what is pitting edema?
from a thrombosis; when you press down on the skin and it stays pressed in
What is the normal fluid intake?
2000-2500ml/d
What are the two types of sensible losses of fluids?
urine and GI (800-1500 and 250)
What are some volume deficit symptoms?
thirst, hypotension, tachycardia, sunken in skull, tenting
What are some reasons for volume excess
dec water excretion, ADH, excess water or isotonic salt solutions
tx for volume excess?
water restriction, hypertonic saline, loop diuretics (inc solute excretion, inc free water excretion, once neg Na balance achieved)
Fluid therapy goals
adequate fluid, provide electrolytes
How do you calculate the normal water intake per day for someone?
1500ml + 20ml/kg over 20kg (or about 30-35 ml/kg)
How do you calculate infusion rate over 24 hours?
ml/24 hours = rate (ml/hr)
What is the difference between crystalloids and colloids and their distribution patterns?
Colloids are big proteins or polymers like Dextan that STAY in the intravascular space and shift fluid from the intersitial space to the intravascular spaces. Crystalloids are solutions where the solutes can go into the extravasular space and intersitial space
What is the normal value of Na?
135-145 mEq/L
What is the function of Na?
control of water distribution and serum osmolality
Is Na intracellular or extracellular?
extracellular
Can renal excretion of Na drop to zero? How?
Yes, Aldosterone
What is more common excess Na or excess fluid loss with no loss of Na to give excess Na?
FLuid deficit in excess of Na losses
What is the tx for hi Na with low water?
give fluid therapy
what is the tx for hi Na with normal water?
give fluid and then furosemide to inc renal Na excretion
What range is mild to moderate hyponatremia?
125-135
What range is severe hyponatremia?
<125
What are some durgs that can cause hyponatremia?
diuretics, SSRI, antiepileptic agents
CHF, SIADH (syndrome of inappropriate antidiuretic hormone)
What can you cause if you infuse too fast into a hyponatremia pt?
osmotic demyelination syndrome
to minimize risk of osmotic demyelination syndrom how fast should you infuse?
not more than 1-2mEq/L per hours or not more than 12mEq/L per 24 hrs or 18mEq/L over first 48 hours
What should you do for hyponatremia?
tx underlying condition
restrict fluid intake
supplement Na
Can you give someone who is hyponatremic vasopressin receptor antagonists
yes, it flushes out water but hold onto Na, K
Should you use vassopressin in pts who are volume depleted?
no, instead use saline replacement therapy as primary therapy
Can Low mg cause low K?
Yes
Can high Mg cause high K?
No
Can cardiac problembs be caused by high or low K?
Yes
Does K contract smooth muscle?
yes
Does K help with protein and glycogen synthesis?
yes
Is K intra or extra cellular?
intracellular
what organ gets ride of K?
kidneys
Can the kidney reduce K excretion to zero if you are low on K?
No, but it can for Na thanks to aldosertone
What is factitious hyuperkalemia?
red blood cells that lyse and inc the serum conc of K giving a false hyperkalemia
Can salt subsititutes inc K?
yes
Can high doses of Penicillin G K cause inc K?
Yes
What are some meds that inc K through decreased excretion?
ACE, ARBs, spironolactone, NSAIDs, cyclosporine, tacrolimus
Can inc release of K from cells happen? How?
lysis, acidosis, medications
How do you tx hyperkalemia?
tx underlying condition, dec/eliminate K intake; then giving drugs depends on severity of hyperkalemia and if there are symptoms of EKG changes
What is severe hyperkalemia numbers?
> 7mEq/L
One treatment for hyperkalemia that doesnt effect plasma K levels or total body stores of K is ________. How does it work
Calcium Gluconate; it antagonizes cardiac and neuromuscleul toxicity of inc K; thus inc threshold protential; and stabilizes excitable cell membranes
What is the place in therapy of Calcium Gluconate?
Its 1st line for severe hyperkalemia with EKG changes, it helps give you time to prevent cardiac events while you figure out the underlying cause of the hyperkalemia
What is the dose and frequency of Ca gluconate for EKG abnormalities from K
10-20ml of 10% Ca gluconate IV over 2-5 mins
What drug must you be care with when giving Ca gluconate therapy?
Digoxin
What is a drug to move K back into the cells (intracellular shift?)
Insulin and dextrose
Insulin stimulate the _____ pump
Na-K-ATPase
is dextrose always needed when giving insulin to correct K levels?
no, not if they are hyperglycemic
What should you monitor when giving insulin to correct hyperkalemia? How many units insulin
K and glu; 10 U
What other drug moves K into the cells besides insulin?
Sodiuim bicarbonate
Is Ca compatible with sodium bicarbonate?
no monitor Ca, potential for hypocalcemic tetany
What electrolyte can you overflow when using Na bicar for hyperkalemia?
Na
How does albuterol lower K levels in the blood?
binds to beta 2 receptor –> cyclic AMP –> protein kinase A –> activates Na K ATPase –> influx of K into the cells with no reduction of TOTal body K
side effects and caution with who when using albuterol?
HR and BP inc (10-20mg) and caution in elderly with CV
What is Kayexalate used for? Where does it work?
Its Sodium polystyrene sulfonate and it exchanges Na for K in the colon and excretes K in feces
What do you monitor for in SPS?
intestinal necrosis and perforation
Can hemodialysis be used for hyperkalemia? When?
Yes, in renal failure, most effective
Can insulin cause hypokalemia?
yes
What is refeeding syndrome?
when you get food too fast after being starved, the body doesnt know how to react properly and you can die from cardiac problems
Can Na bicar cause hypokalemia?albutero?
yes, yes from ANKATPase pump activity
What are some symptoms of refeeding syndrome?
edema, respiratory, cardiac dysfunction, arrhythmias, death
can renal losses cause hypokalemia?
yes
Can you get hypokalemia from gi losses?
yes
Can low Mg contribute to low K?
yes
What is tx for hypokalemia?
Potassium supplementation (Cl, acetate, citrate, bicarb, gluconate, phosphate)
For every 0.3mEq/L dec the body is deficit about 100mEq
True
What is the preferred route of Potassium supplementation?
Oral; prevention 20mEq/day
tx 40-100 mEq/day or more, PRN
What are the indications for parenteral potassium supplementation? What are the three types of parenteral potassium supplememntation? Why is it avoided?
WHY WOULD YOU NEVER GIVE IV PUSH OR IM of potassium?
oral not feasible, severe deficiencies, symptomatic, life-threatening
KCl, Kphos,KAcetate
painful!
IT CAN STOP THE HEART!
Why is it important to supplement Mg before doing K if the Mg stores are super low?
because if you have low mg you will have low K and it potentially wont repsond to K supplements until you restore the Mg
What is the normal fucntion of Ca?
nerve impluses, contraction of muscle, blood coagulation
What is the normal Ca levels in the serum?
8.5-10.3 mg/dL
Where is most of the Ca found in your body?
In the bone
About 50% of ECF Ca is ____ and thus active, the remainder is bound to ________.
active; proteins and anions (phosphate and citrate)
How is Ca excreted?
Kidney
What is the corrected Ca level equation?
Corrected Ca = measured serum Ca + 0.8(4-alb)
Where is Ca; Absorped Adsorption Resorption reabsorption
GI tract
to bone
from bone
from renal tublules after glomerular filtration
What enzyme increases when Ca is low?
ParaThyroid Hormone
What is the function of Parathyroid hormone?
it causes release of Ca and phosphate from the bones, it also causes Ca reabsorption by distal renal tubule
What is the function of calcitonin and when is it high?
it is high when Ca is high;
it inhibits tubular reabsorption of Ca so its pee’d out
it inhibits osteoclastic bone resorption
What is the function of calcitriol (Vit D)
inc intestinal absorption of Ca and phosphate
inc net bone resorption (inc osteoclasts)
inc bone formation
inc renal tubular reabsorption of Ca
What are some reasons for hypercalcemia?
vit d toxicity, vit a toxicity, thiazide diuretics, litium (inc PTH), hyperparapthyroidism, hyperthyroidism
tx for hypercalcemia?
tx underlying cause, dec Ca supplements
If you have hypercalcemia can you give Saline infusion? why?
Yes! it not only reestablishes fluid balance in the person but it also helps by having the Na inhibit tubular reabsorption of Ca, thus allowing you to pee out the excess Ca.
Can furosemide be used in hypercacemia?
Yes, it block Ca reabsorption also like Na
Should you use furosemide before or after you correct dysvolemia?
only use after, you could make dysvolemia worse
What is the dose of furosemide?
20-40mg Q2h IV after rehydration has been achieved to dec Ca
What should you monitor when giving Furosemide to dec hypercalcemia?
monitor K dec and Mg dec and supplement as needed
What type of diuretics should you AVOID in hypercalcemia? why?
thiazide diuretics; dec amount of Ca you excrete in your urine
What is Pamidronate, brand name, and why is it indicated for?
A bisphosphonate that dec osteoclastic bone resorption.
Aredia
hypercalcemia of malignancy
What is a severe high Ca level?
> 13.5mg/dL
How do you reduce the renal toxicity of Pamidronate (Aredia)
inc infusion time (>2hr)
How long should you wait to start a new dose after giving Pamidronate?
7 days
What is Zometa? indication? What population is it aboided in?
bisphosphonate that dec osteoclastic bone resportion
generic name is Zoledronic acid
indication is hypercalcemia of malignancy (max dose of 4mg)
pts at risk of renal impairment
When pts are taking bisphosphonates they should be monitored for what electrolytes
hypo-kalemia,ma,phos,ca
What caution should be taken when using bisphosphonates and the kidnyes
use caution when taking with other nephrotoxic drugs, can progress to renal failure
are the other disphosphonates indicated for hypercalcemia?
No
what is the significat SE of the bisphosphonates?
osteonecrosis of the jaw, subtrochanteric and siaphyseal femoral fractures
What does salmon calcitonin do?
inhibits the osteoclastic bone resorption so that Ca stops getting released into the serum. it also inhibits renal tubular Ca reabsorption so that ca is excreted thus tx hypercalcemia
What are some side effects of salmon calcitonin?
N/V, tachyphylaxis, allergic rxn (test dose first), hypersensitivity
What is gallium nitrate used for?
hypercalcemia; blocks PTH effect on bone; inhibits bone resorption
What is the brand name of gallium nitrate?
Ganite
Can corticosteroids be used to tx hypercalcemia?
yes if its from cancer stuff i think
What is cinacalcet and how does it work?
It is a calcimimetic agent (Brand name: Sensipar) that increases sensitivity of Ca sensing receptor (Ca-R) to activation by extracellular Ca; when Ca of binds to the Ca-R it inhibits the release of PTH
In what pts is Sensipar indicated for?
pts with parathyroid problems
Should you take cincalcet with food?
yes
can you divide the cincalcet tablets?
no
What is the cutoff for initiating Sensipar therapy?
Should not initiate if serum Ca is less that 8.4mg/dL
What are some reasons for hypocalcemia?
dec PTH function (Furosemide or Cinacalcet); altered vit D metabolism (Phynytoin and phenobarbital; binding w/ Ca (phosphate Foscarnet, which chelates divalent cations)
Can Mg dec have an effect of Ca? what effect?
Yes, could cause low Ca by affecting secretion and skeletal response to PTH
Could hyperphosphatemia and massive blood transfusion cause hypocalcemia?
yes and yea from binding
What are the different salt forms of Ca supplementation?
Calcium Carbonate, glubionate, citrate, gluconate, lactate
Which Ca supplements are parenteral?
Calcium gluconate and calcium chloride
Why can’t you mix calcium gluconate with bicarbonate or phosphate?
crystalization i think
What happens if you infuse Ca too fast?
vasodidlation, hypotension, bradycardia, cardiac arrest
What should you monitor when giving Ca and why should you not give CaCl2 IM or SQ?
EKG, BP, pts recieveing digoxin; Because of necrosis
Can you give vit D to help tx hypocalcemia?
yes
can you give Mag if its low to help with hypocalcemia?
yes
If you tx hyperphosphatemia why might that help with hypocalcemia?
because they bind together and could precipitate out
Where is Mg normally found?
intracellular
how is Mg excreted?
kidneys
What is the normal serum levels of Mg?
1.7-2.3
What are some causes of hypermagnesemia?
dec renal excretion, inc gi absorption, supplementation (drugs)
What are some tx for excess Mg?
stop supplementation, saline solution diuresis, loop diuretics, intravenous Ca (enhances renal secretion of Mg), hemodialysis
What are some causes of hypomagnesemia?
inadequeate intake, intracellular redistribution (refeeding syndrome), Gi losses (diarrhea, laxatives, enema, malabsorption)
What are some drugs that contribute to the renal loss of Mg?
Amphotericin B, Cisplatin, Carboplatin, aminoglycosides, loop and thiazide diuretics, osmotic diuresis
How does Foscarnet lower Mg levels?
its chelates divalent cations
What is a side effect from enteric supplementation of Mg?
Diarrhea
What is a painful form of parenteral Mg?
IM
What is the normal level of phosphate?
2.5-4.5
What ion plays a major role in renal exretion of H ions?
phosphate
Where is phosphate usually found?
intracellular
80% of phosphate is located in
bone
What are some causes of hyperphosphatemia?
dec renal excretion, tumor lysis syndrome from chemotherapy, phosphate supplements, Foscarnet
What is the level of CaxP supposed to be?
<55
What does a phosphate binder do?
reduces Gi absorption of Phosphate by binding to phosphate
Al hydroxide and Al carbonate are used as what? What level are they saved for?
phosphate binders; >7 mg/dL (only for 4 wks)
Can Ca salts be used to dec P absorption? How?
yes, form insoluble Ca-P excreted in feces
What is PhosLo?
Ca acetate
What is PhosLo indicated for?
control of hyperphos in ESRD
What is Phoslyra? What is it indicated for?
Calcium acetate; reduction of serum phos in pts w/ ESRD
Can PhosLo cause hyperCa?
Yes
Could PhosLo dec %F of TCNs?
Yes
Should Calcium acetate be given to pts on digitalis?
no, may precipitate cardiac arrhythmias
What is Sevelamer used for?
control of serum phos inp ts w/ CKD on dialysis
What is the brand name of Sevelamer?
Renagel hydrochloride
What is the starting dose of Renagel?
1 or 2 800mg or two to four 400mg tabs TID with meals
What is Revela?
Sevelamer carbonate
Can you just switch gram for gram among sevelamer formulations?
yes
What is sevelamer contraindicated with?
bowel obstruction
What are some side effects of Sevelamer?
dyspepsia, N,V,D, constipations, fecal impaction, ileus, bowel obstruction, bowel perforation
What does Sevelamer do to Cirop %F?
Dec by 50%
administer Cipro _ hours before or _ hours after sevelamer.
1, 3
What is Lanthanum carbonate brand name and what is it used to tx?
Fosrenol, used to tx hyperphophatemia
What is Fosrenol contraindicated in?
bowel obstruction, ileus, fecal impaction
What are some side effects of Fosrenol?
N/D abdominal pain, vominiting, constipation, dyspepsia, allergic skin rxns, hypophosphatemia, tooth injury
Compounds that bind to _______ antacids such as ____ ____ ____ should not be taken withing 2 hours of Fosrenol
cationic; Ca, Mg, Al
Dec _______ %F so you should administer at least 1 hr before or 4 hours after Fosrenol
Cipro (quinolones)
What must you do with levothyroxine when taking Fosrenol?
take 2 hrs before or 2 hrs after fosrenol and monitor the TSH levels
What can cause hypophosphatemia?
inadequate intake, refeeding syndrom, reduced absorption from phosphate binders (Al containing products, Sucralfate, Ca salts, Sevelamer, Lanthanum), Renal wasting, High Ca, Foscarnet, respiratory alkalosis and hypercentilation
What is the tx for hypophosphatemia?
tx underlying condiction, give phosphate supplementation.
what should you first assess before starting phosphate supplementation?
renal fucntion and monitor Ca levels because you could dec Ca or you could exceed the CaxP <55
What dosage form should phosphate never be given as?
Never IV push or IM like potassium
Can you give oral, gastric, enteric? what should you monitor for?
Yes, monitor for hyperkalemia from the K containing products (also causes diarrhea)
How do you determine which to use: NaPhos or KPhos?
you tx with which ever other lab value is low
What are the IVPB phos forms indicated for?
sever hypophosphatemai (<1mg/dL), symptomatic hypophosphatemia or cannot take oral
What are some symptoms of hypophosphatemia?
muscle weakness, acute respiratory failure
What should you monitor when giving IVPb phosphate?
inc phos, inc K, rapid infuction can cause dec Ca, tetany, hypotension, metastatic calcifications