Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key


Play button


Play button




Click to flip

76 Cards in this Set

  • Front
  • Back
What percentage of total body weight in humans is water?
What percentage of total body water is intracellular?
What percentage of extra-cellular water is in the interstitial space?
What percentage of extracellular water is in the plasma?
What are the major cations of the intracellular space?
• potassium
• magnesium
What is the major cation of the extra-cellular space?
What are the major anions of the intra-cellular space?
• phosphate
• protein
What are the major anions of the extra-cellular space?
• chloride
• bicarbonate
What is the normal solute content of body water?
285-295 mOsm/kg of water
What symptoms are associated with mild volume depletion?
• orthostatic dizziness
• tachycardia
What are symptoms of worsening intracellular compartment depletion?
• recumbant tachycardia
• urine output diminishes
What are signs & symptoms of severe volume depletion?
• cool extremities
• vasoconstriction occurs
• hypotension
• mental obtundation
• none to negligible urine output
What are upper GI causes of volume depletion?
• nasogastric suction
• upper GI bleeding
• vomiting
What are lower GI causes of volume depletion?
• colon disease
• diarrhea
• lower GI bleed
What are renal causes of volume depletion?
• acute tubular necrosis
• adrenal insufficiency
• renal tubular acidosis
• use of diuretics
How much volume is loss in order to have tenting, on average?
10% volume loss
Volume excess occurs when salt and water intake exceeds renal and extra-renal losses. What are the 2 general categories of causes of volume excess?
• primary renal sodium retention
• secondary renal sodium retention
List examples of causes of primary renal sodium retention
• acute renal failure
• acute glomerulonephritis
• chronic renal failure
• Cushing's Syndrome
• liver disease
• nephrotic syndrome
• primary hyperaldosteronism
List examples of causes for secondary renal sodium retention
• heart failure
• liver disease
• nephrotic syndrome
• pregnancy
What is the main stay treatment for volume excess?
diet (Na+ restriction)
What are examples of diuretics that can be used to treat volume excess?
• Acetazolamide (carbonic anhyrdase inhibitor)
• Furosemide (loop diuretic)
• Thiazide diuretics
• Potassium-sparing diuretics (ex. Spironolactone)
What is the MOA of acetazolamide?
• blocks proximal tuble reabsorption of Na+/H+
• loss of K+ and HCO3
What is the MOA of loop diuretics?
• decreases Na+/K+/2Cl- transport at the ascending loop of Henle
• other effects are K+ loss, increase H+ secretion, & increased Ca++ excretion
What is the MOA of thiazide diuretics?
• works at distal convoluted tubule
• decreases Na-Cl transport
• K+ loss, increased H+ secretion, decreased Ca++ secretion
What is a common electrolyte imbalance caused by thiazide diuretics?
• K+ loss (hypokalemia)
What is the MOA of Spironolactone?
• Works on distal and proximal tubules,cortical collecting duct
• Decreases NaCl reabsorption
• Decrease Na+ reabsorption
• Decrease K+ loss (potassium-sparing)
• Decrease H+ secretion (causes increase in H+ concentration)
What is the MOA of Triametrene?
• Primary Sodium Channel Blocker
• Works on cortical collecting duct
• Decrease Na+ absorption
• Decrease K+ loss (can cause hyperkalemia)
• Decrease H+ secretion (can cause acidosis)
What is the definition of hyponatremia?
• serum sodium < 130

* most people become symptomatic at sodium levels below 130
What is the most common electrolyte abnormality seen in gernal hospitalized patients?
What are extra-renal (non-renal) causes of hyponatremia?
• Burns
• Diarrhea
• Pancreatitis
• Sweating
• Third spacing
• Vomiting
Describe the sodium and water characteristics of hypovolemic hypotonic hyponatremia
• total Na+ is decreased
• ADH is secreted to compensate for hypovolemia » causes water retention w/o Na+ retention
• occurs in renal & extra-renal volume loss
Describe the sodium and water levels in euvolemic hypotonic hyponatremia
• normal Na+ concentration
• increased total body water
• causes a dilution of sodium leading to hyponatremia

* increase in water is enough to cause dilution, but not enough to increase volume, hence EUVOLEMIC)
Describe sodium and water characteristics in hypervolemic hyponatremia
• increase in total body water
• increase in sodium
• greater increase in total body water
• causes edema formation
What are characteristics of redistributive hyponatremia?
• shift of water from the intracellular to extracellular compartment
• causes subseqent dilution of sodium
• total body sodium is unchanged
Explain how hyperglycemia causes redistributive hyponatremia
increase in sugar will pull water from intracellular to extracellular compartment
What are characteristics of pseudohyponatremia?
• occurs as a result of lipids and/or proteins occypying a disproportionate large portion of the plasma volume
• osmolarlity of the plasma is OK
• decreased volume of water & Na+ concentration
What are renal causes of hypovolemic hyponatremia?
• diurectics (Santana says "most common")
• anion gap acidosis
• mineralocoritcoid deficiency
• partial urinary tract obstruction
• renal tubular acidosis
What are causes of euvolemic hyponatremia?
• hypothyroidism
• post-operative hyponatremia
What are some causes of hypervolemic hyponatremia?
• cirrhosis
• nephrotic syndrome
• renal failure
What are some causes of redistributive hyponatremia?
• hyperglycemia
• Mannitol infusion
What are some causes of pseudohyponatremia?
• hypertriglyceridemia
• Multiple myeloma
What is the clinical presentation for a patient with hyponatremia?
• anorexia
• coma
• disorientation
• generalized weakness
• lethargy
• muscle cramping
• nausea and/or vomiting
• orthostatic hypotension
• seizures
• stupor
What are some labs and diagnostic studies that should be ordered for a patient with suspected hyponatremia?
• urine sodium
• serum sodium (Chem-7)
• BUN & creatinine
• urine & plasma osmolality
• triglycerides
• TSH (if elevated consider CT scan)
• CXR (to R/O tumor causing SIADH)
A patient with hyponatremia has a urine sodium > 20 mEq/L. What does this lab finding indicate?
• cause of the hyponatremia is in the kidney
• kidneys are excreting excess sodium in the urine » sodium leaves the body through the urine » causes hyponatremia
A patient with hyponatremia has a urine sodium less than 10 mEq/L. What does this lab finding imdicate?
• indicates Na+ retention by the kidney (which is a normal function)
• therefore, cause of hyponatremia is not the kidney
Which patients with hyponatremia should be treated?
• treat symptomatic patients
• asymptomatic patients w/ sodium < 125 mEq/L

* if patients are asymptomatic w/ sodium < 125 mEq/L, repeat the lab test (think human error)
What is the treatment for hypovolemic hypotonic hyponatremia?
volume replacement (use isotonic saline or Ringer's lactate)
What is the treatment for euvolemic hypotonic hyponatremia?
• fluid restriction to 1000 mL/day
• treat underlying condition
What is hypernatremia?
• water content of the body is deficient in relation to sodium
• sodium is > 150 mEq/L
What are causes of hypernatremia?
• GI loss
• hypotonic fluid loss
• sodium excess
• urinary loss
• water deficit
Hypernatremia is commonly seen in what patients?
• elderly
• may occur in infants w/ diarrhea
• associated with diabetes insipidus
What are clinical presentations of hypernatremia?
• decrease salivation
• dry mouth & mucosa
• fever
• flushed skin
• hyperreflexia (DTR > +4)
• hyperventilation
• lack of tears
• oliguria & anuria
What level of urine production is considered oliguria?
• < 50 ml/hr
• < 400 ml/24 hrs
What are neurological manifestations of hypernatremia?
• thirst (1st response)
• coma
• convulsion
• delirium
• disorientation
• irritability
• restlessness
A patient with a low urine sodium with polyuria should make you clinically suspicious for what?
diabetes insipidus
What are lab findings of patient in a hyperosmolar coma?
• elevated serum glucose
• decreased urine output
• increased urine osmolality
What is the treatment for hypernatremia?
• free water orally (preferred route)
• IV D5W (because it has less sodium)
• if sodium > 200, then dialysis

* treat hypovolemia first, then hypernatremia
What are complications of rapid correction of hypernatremia?
• central pontine demyelinosis
• pulmonary edema
What is hypokalemia?
• serum K+ < 3.5
• results from the shift of potassium into the intracellular compartment OR
• potassium losses of extra-renal or renal origin
What are common causes of hypokalemia?
• diuretic use
• GI loss
• renal tubular acidosis
What is the most common cause of GI loss of K+?
What is the most common cause of GI loss of H+?
What are clinical features of hypokalemia?
• Cardiovascular
- cardiac arrest
- hypotension
- ventricular arrhytmias

• Neurological
- cramps
- ileus & constipation
- malaise
- skeletal muscle weakness
What are EKG findings of hypokalemia?
• flattened or inverted T waves
• increased prominence of U waves
• depressed ST segment
• venticular ectopy
• Torsades de Pointes
Treatment for non-emergent hypokalemia is oral potassium. At what serum potassium level would you give IV potassium to treat hypokalemia?
K+ < 2.5
If a patient is on Digoxin and is hypokalemia, you should be suspicious of what?
dig toxicity
What is hyperkalemia?
• K > 5.5
• may result from:
- cellular redistribution from intercellular to extracellular compartment
- K+ retention
- hemolysis or thrombocytosis
What are common causes of hyperkalemia?
• ACE inhibitors
• acidosis
• cell death
• renal failure
What are clinical features of hyperkalemia?
• most severe:
- arrhythmia
- cardiac arrest

• neuro:
- flaccid paralysis (decreased tonicity)
- numbness
- tingling
- weakness
What are EKG findings of hyperkalemia?
• peak T waves (early)
• flattening of P waves
• prolongation of the PR interval
• widening of the QRS complex » V-fib
• cardiac arrest
What is the treatment for hyperkalemia?
• treat life-threatening level first
• discontinue potassium-sparing diuretics & potassium additives
• treatment options are:
- calcium gluconate (to antagonize effects of hyperkalemia on the heart)
- sodium bicarb
- glucose
- insulin
- kayexalate (not 1st line; good for non-severe symptoms)
What is hypercalemia?
• serum Ca++ > 10.5 mEq/L
• increased PTH levels results in increased serum Ca++ and decreased phosphorus
What are common disorders that can cause hypercalemia?
• hyperparathyroidism
• malignancy (lung CA, head & neck CA, lymphoma)
• Sarcoidosis
• Vitamin D intoxication
What are clinical features of hypercalcemia?
• anorexia
• change in mental status
• constipation
• dehydration
• nausea (w/o vomiting)
• polyuria
• polydipsea
What are factors that can change the severity of symptoms of hypercalcemia?
• Ca++ levels
• onset
• state of hydration
• underlying malignancy
What is the treatment for hypercalcemia?
• Lasix
• dialysis

• Este also says:
- Calcitonin: 4 units/kg Q12hrs
- Prednisone: 40 mg/day
- Bisphosphonates: Pamidronate 90 mg over 2 hrs
- Zolindronate: 4 mg