Hyper/Hypo BS Flashcards
(45 cards)
What is the main extracellular cation?
Sodium
The “-volemias” refer to what is being perceived on _________ ______
physical exam
In order for this to happen, there must be an increase in both water AND sodium
Hypervolemic Hypernatremia
What is the most common form of hypervolemia hypernatremia?
Iatrogenic – from the administration of sodium bicarbonate
What is another cause of hypervolemia hypernatremia?
Primary aldosteronism
What does primary aldosteronism cause hypervolemia hypernatremia?
Increased aldosterone causes increased sodium reabsorption
sodium reabsorption causes water to passively follow it, which is why hyperaldosteronism can cause hypervolemia
To be hypovolemic and hypernatremic, there must be more _________ loss than _______ loss if one is losing both
more WATER loss, than sodium loss
Losses of water and/or sodium can be classified as renal loses or extrarenal losses – what are examples of both?
renal losses: renal disease or diuretics
extrarenal losses: sweat, stool
If the clinical history and physical exam cannot distinguish between renal and extrarenal losses, what are you going to do!?
Look at their urine – urine electrolytes will tell you the difference!
If the water/sodium loss is occurring extrarenally, will sodium concentration in the urine increase or decrease? why?
Decrease! the kidneys are still working here! so they will hold on to that sodium making the sodium concentration less in the urine!
What if the cause of hypovolemic hypernatremia is renal? what will the sodium urine concentration look like?
HIGH! kidneys suck – can’t hold on to sodium, out it goes.
If the sodium concentration is greater than ____ meq/L the sodium losses are renal. If they are less than ______ meq/L the sodium losses are extrarenal.
20!
Although patients may appear euvolemic, they are technically losing or gaining some water?
Losing
What are the two causes of euvolemic hypernatremia?
Diabetes insipidus and hypodipsia
Whats the difference between central diabetes insipidus and nephrogenic diabetes insipidus?
Central is a problem in the posterior pituitary – you aren’t making ADH
Nephrogenic is when there is no response to ADH
What are two cases when the body inappropriately increases the intravascular volume resulting in hypervolemia, hyponatremia?
Heart failure and cirrhosis
Heart failure and cirrhosis cause hyper or hypovolemia? and hyper or hyponatremia?
Hypervolemia, hyponatremia
To be hypovolemic and hyponatremic, there must be both water and sodium loss, but relatively more ______ loss than ______ loss.
sodium, water
If we can’t tell on physical exam if someone is hypovolemic and hyponatremic, what are we going to do?
Look at the urine
If the urine sodium concentration is greater than 20meq/L, the kidneys must be losing the sodium.
If the urine sodium is less than 20meq/L, the the sodium must be lost in some other way such as sweat, stool, or edema
Adrenal insufficiency, hypoparathyroidism, primary polydipsia, and SIADH can all cause?
Euvolemic hyponatremia
If patients with euvolemic hyponatremia have kidneys that are functioning normally, they will be urinating large or small amounts?
Large! trying to maintain clinical euvolemia
Osmolality refers to the amount of _____ dissolved per kilogram ______
solute, solvent
An increase in glucose, lipids, proteins, or urea will raise or lower serum osmolality? why?
Raise! because they will pull water into the intravascular space to re-equilibrate things.
This would lead to an increased water to sodium ratio and thus hyponatremia.
In uncontrolled diabetes mellitus, the glucose concentration can raise/lower the serum glucose levels?
Raise the serum glucose levels!
Water can be drawn into the intravascular space in an attempt to maintain fluid balance. This can result in hyponatremia and even hyperosmolar coma.
