Electrolytes

Question 1

what is the percentages of body weight for 1) total body water, 2) Intracellular fluid, 3) Extracellular fluid?

Answer 1

Think: 60-40-20 rule

1) 60 % of total body weight (women 50%)
2) 40 % of total body weight
3) 20 % of total body weight

Question 2

what is the percentage of body weight that is plasma? interstitial body fluid?

Answer 2

1) 5%

2) 15%

Question 3

What is the minimum urine output per day?

Answer 3

500-600 mL/day

Question 4

What is the normal output of volume in the body?

Answer 4

1) 800 to 1500 mL per day

Question 5

What are the three most common causes of oliguria?

Answer 5

1) Low blood flow to the kidney
2) Interstitial kidney problem
3) Obstruction

Question 6

When a patient is given hypotonic fluid (1/2 NS or 1/4 NS) where does the solution go to first?

Answer 6

1) It initially is in the extracellular fluid, however, it immediately is transfered to the intracellular fluid to equalize higher osmolarity in cells

Question 7

When should lactated ringer never be used?

Answer 7

In a pt. with hyperkalemia

Question 8

What solution is best to replete intravascular volume?

Answer 8

Lactated ringer’s solution

Question 9

What are some causes of hypovolemia?

Answer 9

1) GI (diarrhea, vomiting, draining fistula, NG suction)
2) Third spacing (ascites, effusions, bowel obstruction)
3) Inadequate intake
4) Polyuria (DKA, diabetes inspidus)
5) Sepsis
6) Trauma

Question 10

What are clinical findings of hypovolemia?

Answer 10

1) Altered mental status, sleepiness
2) Tachycardia, orthostatic hypotension, decreased pulse pressure
3) Oliguria
4) Decreased skin turgor, pallor, and hypothermia
5) Possible acute kidney injury due to prerenal azotemia (BUN/Cr = >15)

Question 11

What are signs of hypervolumeia?

Answer 11

1) JVD
2) Peripheral edema
3) Weight gain
4) Pulmonary rales

Question 12

What are causes of hypervolemia?

Answer 12

1) Iatrogenic
2) Cirrhosis
3) CHF
4) ESRD
5) Nephrotic syndrome

Question 13

How do you determine the maintenance fluid for a hypovolumic pt.

Answer 13

Think: 4/2/1 rule

4 ml/kg x 10 for first 10 kg
2 ml/kg x 10 for the next 10 kg
1 ml/kg x remaining weight for the remaining weight

Question 14

What is the treatment for patients with hypervolemia?

Answer 14

1) Fluid restriction

2) Diuretics

Question 15

What is the result of rapid increase in sodium concentration?

Answer 15

Central pontine demyelination

Question 16

What do you have to be careful of when fixing hypernatremia?

Answer 16

Fluids must be pushed slowly otherwise fluids will shift immediately into brain cells causing cerebral edema