1.2.1 Body Fluids and Electrolyte Disturbances

Question 1

Keep going.

Answer 1

D. 2000 mEq

Question 2

Describe how the six volume and electrolyte disturbance will affect ECF osmolality, ECF volume, ICF osmolality, and ICF volume.

(Basically, fill out this chart.)

Answer 2

See chart.

Question 3

How do you calculate sodium deficit?

Answer 3

Na+ Deficit = TBW x (desired [Na+] - present [Na+])

Question 4

What type of volume and electrolyte distubance is: a 56 y/o man goes hiking then gets lost for 10 days. When rescued, he is barely conscious and taken to hospital. Vitals are 75/55 mm Hg and plasma osmolality of 330 mOsm.

Answer 4

Hypertonic contraction

Question 5

Just when you thought there couldn’t be another one…

Answer 5

C. 7 liters

Question 6

And, another one (in DJ Khaled’s voice)

Answer 6

B. Dextrose (5%) in Water

(If you answered this question wrong, you most likely killed your first fake patient via brainscape)

Question 7

Answer this one.

Answer 7

C. Increased intracellular fluid volume

Question 8

What are the two ways to create a hypotonic body fluid disturbance?

Answer 8

1. by loss of impermeable solutes
2. by addition of water to ECF

Question 9

What are the six types of volume and electrolyte disturbances?

Answer 9

1. Hypotonic Contraction
2. Hypotonic Expansion
3. Isotonic Contraction
4. Isotonic Expansion
5. Hypertonic Contraction
6. Hypertonic Expansion

Question 10

How is MAP affected by ECF expansion?

Answer 10

Increased

Question 11

Can’t stop. Won’t stop.

Answer 11

E. This is an example of a hypotonic contraction

Question 12

List 4 prinicipal regulators of tonicity and ECF volume.

Answer 12

Arginine Vasopressin (AVP or anti-diuretic hormone, ADH): senses increased body fluid osmolality, increases H₂O reabsorption

Thirst: Increases when osmolality is above 290 mOsm

Aldosterone: increases Na+ reabsorption in exchange for K+

Natriuretic Peptides (BNP from ventricular cells and ANP from atrial cells): stimulated by chamber distension, increases H₂0 and sodium output by kidney

Question 13

What are the two ways to create an isotonic fluid disturbance?

Answer 13

1. loss of blood (hemorrhage) will not change the osmolality of the remaining blood or of the ECF
2. infusion of isotonic saline will not change the osmolality of the ECF

Question 14

What is central pontine myelinolysis? In what settings can it occur?

Answer 14

Rapid quadriplegia, basis pontis lesion,

Setting: Alcoholism, liver transplant, electrolyte imbalances

Association: Rapid sodium correction

Question 15

What type of volume and electrolyte distubance is: a 60 y/o man with renal disease such that the kidney has an impaired ability to reabsorb sodium. Sodium loss in the urine is greater than water loss?

Answer 15

Hypotonic Contraction

Question 16

Answer the question.

Answer 16

E. The man’s body fluid disturbance would be described as isotonic contraction

Question 17

What are the two ways to create a hypertonic fluid disturbance?

Answer 17

1. by addition of impermeable solutes (e.g. sodium)
2. by loss of water from the ECF

Question 18

Describe the process in which ECF contraction will lead to decreased MAP.

Answer 18

Decrease in ECF -> Decrease in plasma volume -> Decrease in venous return -> Decrease in preload (EDV) -> Decreased SV -> Decreased CO -> Decreased MAP

(Remember: MAP = CO X TPR)

Question 19

What type of volume and electrolyte distubance is: infusion of 0.9% NaCl?

Answer 19

Isotonic Expansion

Question 20

When the ECF is hypertonic compared to the ICF, what will water do?

Answer 20

Water will move out of the cells into the ECF (Volume of ICF decreases)

Question 21

What is term for an increase in ECF volume? Decrease in ECF volume?

Answer 21

Increase: Expansion

Decrease: Contraction

Question 22

What type of volume and electrolyte distubance is: 19 y/o chugs a liter soy sauce for a bet?

Answer 22

Hypertonic Expansion

Question 23

How was the patient who drank the soy sauce treated?

Answer 23

Anti-seizure medication and 6L of 5% dextrose

Question 24

In the two isotonic fluid disturbances, in what direction will water move b/t the ICF and ECF?

Answer 24

It won’t…

On the other hand, the volume of the ECF has changed

Question 25

What type of volume and electrolyte distubance is: a woman drinking 2 gallons of water for a radio contest.

What type of infusion would have a similar net effect?

Answer 25

Hypotonic Expansion

5% dextrose infusion (b/c dextrose will ultimately be metabolized)

Question 26

When the ECF is hypotonic compared to the ICF, what will water do?

Answer 26

Water will enter the cells (Volume of ICF increases)

Question 27

What type of volume and electrolyte distubance is: a 47 y/o woman in a car accident who loses large amounts of blood?

Answer 27

Isotonic Contraction

Question 28

What is the formula for H₂0 Deficit?

Answer 28

H20 Deficit = Present TBW {(Current[Na+]/Desired[Na+])-1}

Question 29

Review: What is the standard distribution of water b/t the ECF and ICF?

Answer 29

ECF: 1/3 of TBW

ICF: 2/3 of TBW

Question 30

Again.

Answer 30

B. The interstitial volume will have increased by 1.5 L