Electrolytes

Question 0

How do you calculate pts serum osmoles?

Answer 0

2Na + (glu/ 18) + (Bun/ 2.8) = serum osmoles

Question 1

What is the basic work up of hyponatremia?

Answer 1

1. Serum osmoles
2. Urine Na
3. Urine osmoles

Question 2

Causes of Hypertonic Hyponatremia

Answer 2

False elevation

Ingestion: alcohols
Glucose: for every 100 above 100 add 1.6 to your measured Na

Fix alcohol problem or glucose correction

Question 3

Causes of isotonic Hyponatremia

Answer 3

Fats and proteins in sample

No tx of Na needed

Question 4

Hyponatremic patient with Hypotonic Hyponatremia. What’s the first thing you check?

Answer 4

H&P

i.e volume status

Question 5

Patient with hypotonic hypernatremia with hypervolemia (i.e volume overload)

What’s the treatment?

Answer 5

Diuresis

Question 6

Patient with hypotonic hyponatremia and hypovolemia. What’s the treatment?

Answer 6

IVF trial

If they get better continue IV fluids if they get worse it’s probably euvolemic. And you need to water restrict and rule out RATS.

Question 7

In the patient with hypotonic hypernatremia and euvolemia you must rule out RATS.

What is RATS?

Answer 7

Rta IV
Addison’s
Thyroid
Siadh

Question 8

What is the treatment for hypotonic hyponatremia with euvolemia?

Answer 8

Water restriction.

Question 9

In a hyponatremic patient with hypotonic Hyponatremia with a history of fever tachycardia heat exposure or water restriction what is this patients volume status?

Answer 9

Hypovolemic

Tx: IVF

Question 10

In a patient with hyponatremia:

1. Hypotonic serum
2. UNa low (300)

What is this patients volume status and tx?

Answer 10

Volume down

Tx: IVF

Question 11

In a patient with hyponatremia:

1. Hypotonic serum
2. UNa high
3. Uosm low

What is the volume status and tx?

Answer 11

Volume up

Tx: Diuresis

Question 12

And a patient with hyponatremia:

1. Hypotonic serum
2. UNa high
3. Uosm high

What is the diagnosis and treatment?

Answer 12

Euvolemia
SIADH

Tx: vasopressin

Question 13

What is hyponatremia?

Answer 13

Na < 135

Question 14

What is severe hyponatremia?

Answer 14

Technically Na < 125

But for use of 3% saline usually we look at listing 110, coma, or seizures

Question 15

How do you treat symptomatic (Neuro changes) severe hyponatremia? (<110, coma, or seizures)

Answer 15

3% saline

Question 16

How do you calculate how much 3% saline to giveA patient with severe hyponatremia?

Answer 16

1. Na+ deficit
2. Volume of 3% saline needed
3. Time needed for correction
4. Rate of infusion

Question 17

How do you calculate sodium deficit?

Answer 17

Na+ Deficit (mEq) = (Desired Na+ - Measured Na+) x 0.6 L/kg x Weight (kg)

Question 18

How do you calculate volume of 3% saline needed to correct severe hyponatremia?

Answer 18

Volume of 3% Saline = (Na+ Deficit)/513 mEq/L Na+

Question 19

How do you calculate time needed to correct sodium in severe hyponatremia?

Answer 19

Time Needed for Correction = (Desired Na+ - Measured Na+)/0.5 mEq/L per hour

Question 20

How do you calculate infusion rate of 3% saline in severe hyponatremia correction?

Answer 20

Rate = (Volume of 3% Saline)/(Time Needed for Correction)

Question 21

What is hypokalemia?

Answer 21

Hypokalemia is generally defined as a serum potassium level of less than 3.5 mEq/L (3.5 mmol/L). Severe hypokalemia is a level of less than 2.5 mEq/L.

Question 22

How much K to give?

Answer 22

10 mEq to move up 0.1 for K >3

(100 mEq to get to 4 over 10 hours)

15mEq for every 0.1 between 2.5 and 3.0 (75mEq)

20mEq for every 0.1 between 2.0 and 2.5 (100mEq)

Question 23

What’s the first thing you do if you have hyperkalemia?

Answer 23

EKG and recheck potassium

Question 24

Treatment in hyperkalemia

Answer 24

1. IV CaCl
2. 10 U regular insulin, 1 amp D50, 10mg albuterol, maybe NaBicarb
3. Kayexalate, DIALYSIS

Question 25

EKG changes in hyperK

Answer 25

1. Wide QRS
2. Peaked t waves
3. Sinusoidal waves

Question 26

Severe Hyponatremia with coma or other neuro sxs line seizures. How do you treat?

Answer 26

Any patient with suspected hyponatremic encephalopathy should receive a 2 cc/kg bolus of 3% NaCl with a maximum of 100 cc, which could be repeated 1-2 times if symptoms persist. Then fluid restrict and call renal.