Na and K Flashcards
most of NA is intracellular or extracellular
Extracellular
NA is regulated by what 3 hormones
what does each do to NA
aldosterone - conserves or reabsorbs NA
natriuretic peptide - excretes NA
ADH - balances water
what lab value is considered hypernatremia
above 140 mEq/L
what is hypernatremia caused by
rarely NOT caused by excess sodium intake - drinking seawater or salty liquids like soy sauce
but RATHER caused by decrease in free water in the body aka DEHYDRATION
if the amount of water ingested consistently is below the amount of water lost, the serum sodium levels will __
increase leading hypernatremia
even a small rise in serum sodium concentration above normal ranges results in what
strong sensation of thirst,
increase in free water intake,
results in correction of abnormality
hypernatremia most often occurs in what people
infants
impaired mental status individuals
elderly
(inability to get water when needed)
what are the symptoms of hypernatremia
thirst dry mucous membranes agitation restlessness weakness irritability neuromuscular excitability edema
hypernatremia is seen in increased intake or decreased loss due to what diseases or conditions
steroids laxatives cough medicine cushings syndrome hyperaldosteronism excessive sweating diarrhea dehydration
what is the lab value that is considered hyponatremia
below 125 mEq/L
hyponatremia is due to what
excess body water or intake (OVERHYDRATION) which dilutes the serum sodium
hyponatremia is often a complication of medial illness such as __
congestive heart failure
syndrome of inappropriate antidiuretic
hormone (SIADH)
polydipsia
exercise associated hyponatremia
exercise associated hyponatremia is seen in what people
marathon runners
endurance events
hyponatremia below 125 has what symptoms
hyponatermia below 115 has what symptoms
below 125 - weakness
below 115 - confusion and lethargy
hyponatremia is seen in decreased intake or increased loss of Na which is seen in what conditions
diuretics carbamazepine ACEI NSAIDs vomiting/diarrhea chronic renal insufficiency addisons disease excessive water intake hyperglycemia CHF peripheral edema SIADH
most of K is intracellular or extracellular
intracellular
Na+ and K+ are both considered what
cations
what are the normal K serum levels
4 mEq/L
what ion is important in maintaining membrane potentials in neuromuscular tissue
K
which ion is said to have minor changes that cause major effects
K
what affect does aldosterone have on K
decreases levels of K by causing excretion
extreme hyperkalemia is a medical emergency due to the risk of what
fatal abnormal arrhythmias
what are the symptoms of hyperkalemia
nausea/vomiting diarrhea malaise palpitations muscle weakness
during the medical history intake for a patient with hyperkalemia, what should one focus on
kidney disease and medication use
hyperkalemia can be due to what
increased dietary intake addisons hypoaldosteronism aldosterone inhibiting diuretics - spironolactone crush syndromes hemolysis infection
what is hypokalemia
condition in which the concentration of K in the blood is low
mild hypokalemia often presents as what
without symptoms or small elevation of blood pressure
rarely arrhythmias
moderate hypokalemia often presents as what
muscular weakness
myalgia
muscle cramps
constipation
disturbs skeletal and smooth muscle
moderate hypokalemia is indicated by what lab level
2.5-3 mEq/L
what are the symptoms of hypokalemia
weakness
paralysis
hyporeflexia
ileus
what causes hypokalemia
hyperaldosteronism
dietary deficiency
licorice
cushings
Cl is the major intracellular/extracellular anion/cation
extracellular anion
Cl follows __ to support electrical neutrality
what follows Cl
Cl follows Na
water follows Cl
affects water balance
what is primarily associated with acid base balance
what also aids in acid base balance
how
CO2
Cl
if CO2 and H elevate, then biocarbonate moves out of cells and Cl moves into cells
hypo or hyperchloremia does not occur alone, but only with shifts of __ and __
Na and bicarbonate
what do you measure to evaluate CO2
h2c03
dissolved CO2
bicarbonate
what is the difference between cations and anions in the extracellular space
anion gap
how is anion gap calculated
(sodium + potassium) - (chloride + bicarbonate)
or
sodium - (chloride - bicarbonate)
what is anion gap used for
increased indicates what
decreased indicates what
used to determine metabolic acidosis
increases with acidosis, diarrhea, and kidney disease
decreases from alkalosis, vomiting, and hyperaldosteronism
what does osmolality measure
measures the dissolved particles in blood
as free water in the blood increases, particles __, and osmolality __
decrease
decrease
as free water in the blood decreases, particles ___, and osmolality __
increase
increase
low osmolality causes what
decrease secretion of ADH, which increases urine output, which raises osmolality
high osmolality causes what
increase secretion of ADH, which decreases urine output, which decreases osmolality
what are the most important solutes in blood
Na, glucose, BUN
how do you calculate osmolality
2Na + glucose/18 + BUN/2.8
