Electrolyte Cases (Johns) - W1

Question 1

Patient presents with hyponatremia, high urine osmolarity, high urine sodium.

Answer 1

• check Bun:Cr for if hypo or hypervolemic - ratio would be increased.
  
  • patients normal
• measured osmo of 248 close to calculated of 241. less than 10 is acceptable - no osmolar gap. Indicates TURE HYPOOSMOLAR HYPONATREMIA.
• too much water - check urine
• urine osmo is HIGH (more than 2x body) = inappropraite ADH

Question 2

if the person is hyponatremic and has too much water, what would you expect of the urine omso and specific gravity

Answer 2

should have low urine osmo and specific gravity as kidney tries to get rid of exces water

Question 3

What could cause SIADH

Answer 3

pain

nausea

meds

lung tumor

Question 4

How does SIADH present?

Answer 4

• hyponatremia
• high urine osmolatirty
• high urine sodium

Question 5

What is seen with 1 week of watery diarrhea?

Answer 5

• Hyponatremia - low urine sodium suggests that kidney percieves volume status as depleted
• urine osmo > serum osmo. - suggests presence of ADH.
• non-anion gap metabolic acidosis - typical w/diarrhea
• diarrhea decreases bicarbonate and potassium

Question 6

What is seen with ingesting too much water?

Answer 6

• hyponatremia
  
  • but normal K, HCO2, BUN and Cr.
• low urine sodium
• very low urine osmo - ADH suppressed

Question 7

What is seen with chronic lithium therapy

Answer 7

• Hypernatremia
  
  • check volume status - normal bun:cr
  • may be increasing water state.
• polyuria (>3L output per day)
• normal daily solute (204 x 4) - 816 (600 to 900)
  
  • indicates water diuresis - abnormal ADH
  • nephrogenic = kidney
  • neurogenic = hypoathalmus

Question 8

What is seen with no WATER OR ORAL INTAKE for 2 days?

Answer 8

• Hypernatremia
• low urine sodium though. Suggests volume depletion.
• High urine osmo - suggests ADH present.
• hypovolemic hypernatremia

Question 9

Patient with ethylene glycol ingestion - what is seen

Answer 9

• anion gap metabolic acidosis
• elevated osmo gap - lab is 315, calucated is 295
  
  • suggests presence of low molecular weight alcohol
• crystal stones

Question 10

What is seen with PCP and vomitting

Answer 10

• anion gap metabolic acidosis - had preexisting metabolic alkalosis
  
  • chloride response = urine cl <10 - his is.
  • suggests vomitting