Electrolyte imbalance

Question 1

Mild/chonic hyponatremia

Answer 1

Asymptomatic, impaired attention, altered gait, fall risk (slow firing neuron’s)

Question 2

Serum osmolality calc

Answer 2

2*[Na] + [glucose] + BUN

Question 3

Moderate to severe hyponatremia

Answer 3

GI upset, headache, lethargy, altered mental status, seizures, respiratory assest
Severity depends on rate of Na loss

Question 4

SrNa <135 mmol/L
Sr Osm <280 mOsm/L (low)
postural hypotension
Urine Osm >450mOsm/kg (high)
Una <20 mEq/L

Answer 4

Sodium loss from extra renal sources or Urine Na would be higher. Urine is still very concentrated to try and retain water. Look for sweating, vomiting

Question 5

SrNa <135 mmol/L
Sr Osm <280 mOsm/L (low)
postural hypotension
Urine Osm >450mOsm/kg (high)
Una >20 mEq/L

Answer 5

Sodium loss in kidneys, check for diuretics or adrenal insufficiency and loss of aldosterone secretion

Question 6

SrNa <135 mmol/L (low)
Sr Osm <280 mOsm/L (low)
Urine Osm <100 mOsm/kg (low)
Una <20 mEq/L

Answer 6

Euvolemic hyponatremia
primary polydipsia is likely, from diabetes

Question 7

SrNa <135 mmol/L (low)
Sr Osm <280 mOsm/L (low)
Urine Osm >100 mOsm/kg
Una >20 mEq/L

Answer 7

Euvolemic hyponatremia
hypothyroidism, hypocortisolism, kidney failure, SIADH

Question 8

SrNa <135 mmol/L (low)
Sr Osm <280 mOsm/L (low)
Edema
Urine Osm >100 mOsm/kg (low)
Una <20 mEq/L

Answer 8

Fluid over load is leading to hypervolemic edema and diluted electrolytes in the blood. Organ failure of heart, liver or kidney is likely

Question 9

SIADH

Answer 9

inappropriate antidiuretic hormone
Can be from tumors, CNS disorder. Basically throws away Na but keeps fluids

Question 10

SIADH drugs

Answer 10

Tricyclic Antidepressants, opioids, nicotine, bromocriptine, NSAIDS, acetaminophen

Question 11

Pseudohyponatremia

Answer 11

If the patient has elevated proteins or cholesterol in the blood this can reduce the fraction of Na in the sample causing it to look like hyponatremia

Question 12

Lab tests for Na imbalance

Answer 12

Serum sodium concentration
plasma osmolarity
urine analysis (osmoses and [Na])
glucose, lipid, SrCr, thyroid, ALT + AST and troponin to check for organ failure if hypervolemic

Question 13

Na increase

Answer 13

No faster than 6-12 mmil/L in 24 hours to prevent demyelination

Question 14

hyponatremia treatment

Answer 14

Hypertonic 3% saline for very serious
0.9% Saline to correct vascular volume and prevent ADH release to prevent Na loss
Oral replacement
Sx should go away after 5% increase or reaching 120mmol/L

Question 15

Hypervolemic treatment

Answer 15

Underlaying causes
Fluid restriction to pull water out of extracellular space (1-1.2L/day)
Sodium restriction (1-2g/day) prevent water retention
Vasopressin antagonists (tolvaptan) if very bad V2 receptor antagonist (prevents water reabsorption)

Question 16

Euvolemic treatment

Answer 16

Underlaying cause
SIADH, hormone imbalance or polydipsia
tolvaptan if really bad
Fluid restriction 1-1.2ml/day

Question 17

hypernatremia picture

Answer 17

Serum Na >145 or >160 if severe
weakness, lethargy, restlessness, irritable, twitching (neruon’s are excited)
severe can lead to seizures and coma

Question 18

SrNa >145
BP is low

Answer 18

Hypovolemic
water loss is fast than Na loss via sweating, diarrhea or vomiting
Christ response can usually solve this

Question 19

hypovolemic hypernatremia treatment

Answer 19

If stable use oral fluids with salt
If unstable use normal saline
200-300ml/h for adults
10-20ml/kg/h for kids
change to 1/2 saline once stable

Question 20

SrNa >145
BP is normal

Answer 20

water loss is crazy >3L per day
diabetes insipidus is most common cause

Question 21

central euvolemic hypernatremia

Answer 21

Caused by inability to produce vasopressin from tumour, head trauma

Question 22

Nephrogenic euvolemic hypernatremia

Answer 22

Renal tubules don’t respond to vasopressin (Lithium, hypokalemia, hypercalcemia or kidney disease) can cause this slowly

Question 23

Nephrogenic euvolemic hypernatremia treatment

Answer 23

Stop drug and correct other ion imbalances
limit Na intake and start thiazide diuretic to reduce Na

Question 24

SrNa >145
BP is high

Answer 24

sodium overload from 3% saline overcorrection or excessive oral intake
Give D5W (little vascular fluid retention) and loop diuretic to lower Na

Question 25

hypochloremia

Answer 25

Usually follows Na and will be lost during vomiting or diarrhea, can lead to metabolic alkalosis

Question 26

Hyperchloremia

Answer 26

associated with metabolic acidosis and hypernatremia