Diuretics & Electrolytes Flashcards
diuretic due to blockade of carbonic anhydrase, principal uses include urinary alkalinization, treatment of metabolic alkalosis, acute mountain sickness and glaucoma
acetazolamide
causes hyperkalemia until that excess plasma K+ is excreted, and then hypokalemia is a possibility
acidosis
when Fanconi syndrome is caused by multiple myeloma or nephrotic syndrome, for example, the condition is characterized as being ______
acquired
aka vasopressin, released by posterior pituitary, plasma levels of this are not normally affected by blood volume, but go up dramatically (e.g., higher than seen with osmolality changes) when effective plasma volume is more than 10% below its set point
ADH
5% solution could be infused to try to expand the plasma volume; low levels of this in plasma decrease total Ca2+ without decreasing ionized Ca2+ (so need to calculate this value)
albumin
adrenal hormone that promotes K+ excretion with Na+ retention; low levels during hypokalemia act to keep K+ from entering cells while high levels during hyperkalemia facilitate the exit of excess K+ from cells for renal elimination
aldosterone
administration corrects plasma K+ levels in type 1 RTA, can worsen them in type 2 RTA if it ends up in urine
alkali
a diuretic that blocks epithelial sodium channels (EnaC) in the principal cells of the collecting ducts
amiloride
potent vasoconstrictor and sodium retaining hormone due to direct effects in kidney, its selective efferent constriction helps maintain GFR as renal perfusion pressure falls, also stimulates aldosterone secretion
angiotensin II
electroneutrality principle states that there must be one of these for every cation in a compartment; the charge separated when combination of concentration difference and permeabilities means that one of the particles would prefer to be in another compartment is what gives rise to membrane and transepithelial potential differences (voltages)
anion
abbr., released from the heart by overfilling, acts in the kidney to increase GFR and decrease Na reabsorption (= increase Na excretion) to cause a decrease in effective plasma volume
ANP
substance that promotes free water clearance
aquaretic
occurs in liver disease due to impaired synthesis of plasma proteins and increased portal venous pressure
ascites
occurs in kidney at least in part by tubuloglomerular feedback and myogenic mechanism, means that GFR and RBF are approximately constant over a mean arterial pressure range of ~90 to 150 mm Hg
autoregulation
syndrome with effects similar to a loop diuretic… urinary loss of Na+, K+, Ca2+, Mg2+, hypochloremic metabolic alkalosis, inability to concentrate or dilute urine
Bartter
contains most of the Ca2+ and phosphate in the body and ~half of the Mg2+
bone
surprising consequence of hyperkalemia, occurs because hyperkalemia increases K+ conductance in SA nodal tissue enough to cause membrane hyperpolarization; other regions of heart do become hyperexcitable so arrhythmias likely
bradycardia
swelling of this organ by rapid onset hyponatremia or too-rapid correction of chronic hypernatremia can have catastrophic consequences
brain
a loop diuretic with similar adverse effects as furosemide but a more predictable oral absorption, doesn’t end in “semide”
bumetanide
expression is increased in DCT by calcitriol, needed for transcellular movement of large amounts of Ca2+ without causing apoptosis
calbindin
calcium regulatory hormone often ignored, it promotes excretion of both Ca2+ and PO4—
calcitonin
1,25 OH vitamin D3, the biologically active form that promotes intestinal absorption of Ca2+ and PO4— and the breakdown of bone to release Ca2+ and PO4—
calcitriol
administered IV to quickly antagonize cardiac effects of hyperkalemia (raises the action potential threshold)
calcium
a cause of real hyperkalemia and pseudohyperkalemia (2 words)
cell lysis
refers to form of diabetes insipidus when damage to the hypothalamus or posterior pituitary gland disrupts ADH release
central
similar to hydrochlorothiazide but longer half-life, favored by some hypertension specialists in part because it is the only thiazide with proven cardiovascular benefits; doesn’t end in “thiazide”
chlorthalidone
characterizes 1:40,000 incidence of Gitelman syndrome relative to that of Bartter and especially Liddle syndrome
common
ability impaired in the kidney by loop diuretics, Bartter syndrome and hypokalemia (here presumably due to need for K+ by Na+-K+-2Cl- cotransporter) resulting in polyuria and nocturia (2 words)
concentrating
prototype for the non-peptide V2 receptor antagonists that can be used judiciously to treat euvolemic and hypervolemic hyponatremia unresponsive to fluid restriction; causes water excretion without solute excretion
conivaptan
common abbr., infused when the ultimate objective is to add water to the body without solute
d5w
osmotic _____ syndrome (formerly called central pontine myelinolysis) is ~irreversible consequence of correcting hyponatremia too rapidly (among its manifestations is the “locked-in” syndrome where patients are awake but unable to move or communicate, except perhaps by blinking)
demyelination
cause of hypokalemia; inability of glucose to enter cells keeps K+ in plasma and loss of glucose in urine then creates polyuria/volume contraction which stimulates aldo release and that plasma K+ is therefore also excreted in the urine (2 words)
diabetes mellitus
an extrarenal cause of hypovolemia and often hypokalemia (and hypomagnesemia) with metabolic acidosis; it can be induced by magnesium ingestion
diarrhea
substance that promotes excretion of urine
diuretic
whether extracellular or intracellular, means that too much sodium is in this compartment (water followed); common indication for a loop diuretic
edema
having tone fall in this arteriole decreases glomerular hydrostatic pressure; GFR falls but remaining kidney function is better preserved (e.g., in diabetes)
efferent
its effects on cells with beta2 receptors on skeletal muscle causes K+ uptake while binding to alpha receptors on hepatocytes promotes K+ efflux
epinephrine
aldosterone antagonist with greater selectivity than spironolactone
eplerenone
loop diuretic that can be used by patients with sulfa allergy
ethacrynic acid
causes a rise in extracellular K+; happens because Na+ influx with K+ efflux occurred during cell activation +/- depletion of ATP reserves needed for its restoration to baseline
exercise
hypovolemic hyponatremia with low sodium in the urine suggests Na+ was lost due to vomiting, diarrhea, third spacing of fluids, etc., collectively referred to as this type of Na loss
extrarenal
syndrome typically considered a general defect in the function of proximal tubule where solutes that are normal reabsorbed such as glucose, amino acids, phosphate, uric acid and bicarbonate are passed into the urine
Fanconi
released by bone, it acts in kidney to promote PO4— excretion; a major regulator of PO4— excretion with familial abnormalities and instances of ectopic secretion
FGF-23
type of paralysis associated with hyperkalemia; somatic nerves fired/released Ach once but cannot repolarize to fire again (i.e., resting membrane potential is above threshold potential)
flaccid
with a sodium load, an increase in this in the distal tubule increases K+ secretion while the associated decrease in aldosterone decreases K+ secretion, together allowing for elimination of excess sodium without K+ loss or retention (2 words)
flowrate
this clearance is zero when urine is isotonic, positive when urine is dilute and negative when urine is hypertonic; negative means that the water in which urinary solute was diluted has been returned to the body to dilute to lower plasma osmolality
free-water
can be administered along with saline to treat hypercalcemia
furosemide
when low, Na+, K+, H+, Mg2 +, PO4— and urea are among the solutes kidneys struggle to eliminate
GFR
syndrome with effects similar to a thiazide diuretic typically manifesting in late childhood/early adolescence characterized by urinary loss of Na+ and K+ with hypochloremic metabolic alkalosis, < normal urinary loss of Ca2+ but much loss of Mg2+ leading to severe hypomagnesemia (a reflection of reabsorption differences for Mg2+ and Ca2+ in the proximal tubule)
Gitelman
balance that represents a combination of physical forces intrinsic to the kidney that helps keep proximal tubular reabsorption proportional to GFR
glomerulotubular
potential adverse effect of spironolactone use by males
gynecomastia
chemical abbr, examples where it can be lost in excess of Na+ to cause hypernatremia include exhaled air, sweat and when paired with glucose in urine
H2O
abbr, plasma levels of this can be < 10 mEq/L in type 1 RTA, range from 12 -20 mEq/L in type 2 RTA depending upon degree of distal compensation, and are typically > 17 in type 4 RTA
HCO3
___ metals, refers to elemts such as cadmium, lead and mercury that damage the proximal tubule to cause Fanconi syndrome
heavy
chicory, dandelion leaves, fennel, goldenseal and many others are diuretics of this type of alternative medicine with generally uncharacterized mechanisms of action and uncertain efficacy
herbal
potential adverse effect of spironolactone use by females
hirsutism
ion that exchanges with cellular K+ during acid-base maintenance and/or compensation; reason acidosis can cause hyperkalemia
hydrogen
pressure that exists across the capillaries that is not present across cell membranes, drives filtration in glomerulus, increased in capillaries by plasma volume overload, heart failure, venous obstruction/valve dysfunction and arteriolar vasodilatation
hydrostatic
a good guess if patient is hypertensive, hypervolemic, hypernatremic and hypokalemic with metabolic alkalosis; converse suggests hypo___
hyperaldosteronism