Chapter 108 - Sodium and water balance

Question 1

True or false - urea is an effective osmole

Answer 1

false

Question 2

When plasma osmolality increases, the hypothalamus increases water intake via thirst and decreases water excretion via what?

Answer 2

secretion of ADH from the posterior pit

Question 3

non-osmotic stimulation of ADH in the face of hypovolemia results in what (tonicity and natremia)?

Answer 3

hypotonic hyponatremia

Question 4

Hypotonic hyponatremia with normovlemia is most commonly due to what?

Answer 4

innapropriate ADH secretion, psychogenic polydipsia or iatrogenic mechanisms

Question 5

What disease state could lead to hypervolemic hyponatremia?

Answer 5

kidney failure, nephrotic syndrome, congestive heart failure

Question 6

In patients with severe/neurological acute hyponatremia, hypertonic saline can be given to raise the sodium concentration by what amount? (mEq/L)

Answer 6

4-6mEq/L

Question 7

Elevation of sodium should not exceed what value in the first 24 hours or resuscitation?

Answer 7

10mEq/L

Question 8

At what rate do you aim to correct acute hypernatremia? (mEq/L/hr)

Answer 8

1-2

Question 9

At what rate do you aim to correct chronic hypernatremia? (mEq/L/hr)

Answer 9

<0.5mEq/L/h