Electrolytes & Fluid HY Flashcards
Hyposthenuria is the inability of the kidneys to concentrate urine and can occur in patients with ____. Patients have polyuria, low urine specific gravity, and normal serum sodium.
sickle cell disease and sickle cell trait
Treatment of Hypercalcemia in acute setting?
(weakness, GI distress, AMS)
Initial treatment: Normal Saline then calcitonin
Chronic tx: Bisphosphonates
The kidneys compensate for primary metabolic acidosis via increased HCO3− (bicarb) reabsorption and H+ (acid) excretion.
↑ bicarb reabsorption via → ↑ urinary _____
↑ acid excretion via → ↑ urinary ____
↑ chloride (Cl−) excretion
↑ ammonium (NH4+) excretion
(or dihydrogen phosphate (titratable acid))
_____ is necessary for HCO3− (bicarb) reabsorption in the renal proximal tubule; thus it is increased in response to metabolic acidosis.
Carbonic anhydrase
(Converts CO2 + H2O to/ from
H+ & HCO3-)
Bulimia (excessive vomiting) leads to volume depletion and metabolic ___.
Labs show: ↑ bicarb ↓K+ ↓Cl-
Treatment of electrolyte derangement is with what?
Alkalosis
Tx: normal saline
(restores intravascular volume & replenishes chloride, thus allowing renal elimination of bicarbonate)
Acetazolamide is a ____ that decreases proximal tubular reabsorption of sodium (Na+) and HCO3−, thereby promoting mild metabolic acidosis.
carbonic anhydrase inhibitor
Loss of HCO3− increases serum Cl− to maintain an electronegative balance. Due to this relationship, NAGMA is also referred to as ___.
hyperchloremic acidosis
high drain output of pancreatic fluid the patient is likely to develop primary metabolic acidosis (low pH, low bicarbonate) with a normal anion gap and compensatory ____.
respiratory alkalosis (low PaCO2)
Nonanion gap metabolic acidosis (NAGMA) results from the loss of ____.
bicarbonate (HCO3−)
Because exocrine pancreatic secretions are high in HCO3−, NAGMA is expected with large-volume fluid losses from the pancreas (pancreatic duct leak/fistula or high drain output) or ____.
small intestine:
high ileostomy output
enterocutaneous fistula
Excessive _____ causes hyperchloremic metabolic acidosis (formerly called dilutional acidosis).
Because an increase in chloride ions drives bicarbonate intracellularly to maintain electronegativity, which causes NAGMA (low pH & low bicarbonate).
infusion of normal saline
(NaCl)
a potassium-sparing diuretic that blocks the epithelial sodium channel (ENaC) in the renal collecting system.
amiloride
(Spironolactone is an MR antagonist)
Patients with asymptomatic mild or moderate hyperkalemia (<6.5) can usually be managed with medication or dietary changes.
Those with severe manifestations of hyperkalemia require urgent therapy (Calcium gluconate, insulin + dextrose).
Medications that cause Hyperkalemia (8)
ACE inhibitor
ARB
Cyclosporine
Digoxin
Nonselective β blockers
Potassium-sparing diuretic (amiloride, spironolactone)
Succinylcholine
Trimethoprim
The goal of hypertonic saline infusion is to correct hyponatremia levels by 4-6 mEq/L over a period of hours to reduce the risk of ____.
brain herniation (cerebral edema)
The maximum rate of correction for hyponatremia is __ mEq/L in 24 hours to prevent osmotic demyelination syndrome (ODS) aka Central Pontine Myelinolysis (CPM).
8
used for the treatment of patients with chronic hyponatremia due to SIADH
Vasopressin receptor antagonists
Tolvaptan
Occurs due to a combination of excessive hypotonic fluid intake and nonosmotically mediated release of inappropriately high levels of antidiuretic hormone causing hyponatremia.
In severe cases, patients may experience seizures, profound confusion, and even death.
Exercise-associated hyponatremia
Hypernatremia should then be corrected gradually ( __ mEq/L/hr) to prevent neurologic complications (cerebral edema) from excessive movement of water into brain cells.
<0.5
Acute treatment of Hyperkalemia with calcium gluconate to stabilize the cardiac membrane and insulin + glucose to shift serum potassium into cells.
Definitive removal of potassium via the stool (____), kidneys (___), and/or blood (____) should then be initiated.
patiromer
furosemide
hemodialysis
Sodium nitroprusside infusion can result in _____, particularly in patients with renal insufficiency. Clinical findings include:
metabolic acidosis and neurologic changes (headache, confusion, hyper-reflexia).
cyanide toxicity
(other sxs: flushed skin, respiratory distress, GI distress, arrhythmia)
Acute ____ intoxication should be suspected in patients with the triad of tinnitus, fever, and tachypnea.
It usually causes a mixed primary respiratory alkalosis and primary metabolic acidosis with arterial ____ pH
salicylate (Aspirin)
normal pH (no osmolal gap)
_____ should be considered in infants with a nonanion gap metabolic acidosis, particularly in the setting of children with growth failure and absence of gastrointestinal loss (diarrhea).
Renal tubular acidosis
A defect in either hydrogen excretion (type 1) or bicarbonate resorption (type 2) in the kidney.
_____ of HCO3− occurs with infusion of excess normal saline (NaCl) and leads to NAGMA.
Intracellular shift
The normal anion gap of 10-14 mEq/L is consistent with nonanion gap metabolic acidosis (NAGMA), which results from ____.
loss of HCO3− (bicarb)
Cause of NAGMA from net bicarb loss is likely due to _____.
A common complication of Sjögren syndrome.
type 1 renal tubular acidosis (RTA)
⎯
impaired H+ excretion
Hypokalemia
urine pH >5.5 (not acidic)
Cause of NAGMA from net bicarb loss.
Type 4 RTA results from reduced ___ activity, leading to impaired __ & __ excretion in the collecting duct. HYPERkalemia is typical.
The urine pH is usually <5.5 (normal).
aldosterone
impaired H+ and K+ excretion
Cause of NAGMA from net bicarb loss.
Type 2 (proximal) RTA results from impaired ___ in the proximal tubule.
Hypokalemia is typical.
Urine pH is variable & often <5.5 (normal).
HCO3− reabsorption
Cause of NAGMA from net bicarb loss.
Type 1 (distal) RTA results from impaired ____ by alpha-intercalated cells in the distal tubule.
Hypokalemia is typical (s/t reduced K+ reabsorption)
Urine pH ___ (s/t markedly impaired capacity to acidify the urine)
H+ excretion
>5.5 (basic)
Electrolyte abnormalities that can be induced by thiazide (chlorthalidone, hydrochlorothiazide) diuretics include (4)
hyponatremia
hypokalemia
hypomagnesemia
hyper calcemia
Adverse metabolic effects of thiazide diuretics are dose-dependent include (4)
hyperglycemia (glucose intolerance)
increased LDL cholesterol
increased triglycerides
Hyperuricemia (gout risk)
Patients with CKD taking ACE-I often develop chronic mild or moderate hyperkalemia.
Typically managed with a low-potassium diet and what medication?
an oral cation exchange agent
(patiromer, zirconium cyclosilicate)
binds to K+ in the colon to be pooped out
Kayexalate (Sodium Polystyrene) Potassium Binders
Hypokalemia or Hyperkalemia with
↑ Chloride
↓ Bicarb
= Hyperchloremic Metabolic Acidosis
List one cause that could cause either of this presentation
Renal Tubular Acidosis (RTA)
⎯
⬩Hypokalemia → RTA (1 or 2)
⬩Hyperkalemia → RTA (4)
Type 4 RTA (hyperkalemic RTA) is commonly seen in elderly patients who have poorly controlled ____ with damage to the juxtaglomerular apparatus,
which causes ↓ Renin & ↓ Aldosterone
diabetes
Although diarrhea most commonly causes metabolic ____,
diarrhea from laxative abuse often causes metabolic ___ & ___.
Acidosis
ALkaLosis (Laxative abuse) & hypokalemia
Loop diuretic use causes hypocalcemia, _____ and metabolic ____.
hypokalemia
aLkaLosis