Fluid Balance

Question 1

What is the likely cause of hyponatraemia with hypovolaemia?

Answer 1

Na deficit - Over diuresis

Question 2

How much water is there in the body and what proportion of weight does it make?

Answer 2

42L

~33%

Question 3

What percentage of total potassium is EC?

Answer 3

2%

Question 4

What are the major ions of the extracellular compartment?

Answer 4

Na and Cl

Question 5

What is the equation for O2 delivery?

Answer 5

O2 Delivery = Hb x SaO2 x HR x 1.34

Question 6

In term of ECV and ICV, compare what happens when water or saline is added or lost from the body?

Answer 6

Water: water will be lost or added to both the ECV and ICV

Saline: saline will be added or lost to only the ECV

Question 7

What pharmaceuticals increase K flow into cells?

Answer 7

Insulin

Beta-agonists

aldosterone

Question 8

When N/saline is given where does it go predominantly? EC or IC?

Answer 8

Extracellular

Question 9

What are the major ions of the intracellular compartment?

Answer 9

K and organic anions

Question 10

Where does saline typically travel to?

Answer 10

ECF

(only 3/14 will go to IV)

Question 11

How much Na and Cl is contained in 1L of normal saline?

Answer 11

154mol

Question 12

What are colloids?

Answer 12

Fluid with large molecules in it

Question 13

Where does 5% dextrose fluid typically distribute to?

Answer 13

ICS and ECS as water is a total body fluid

Question 14

What proportion of total body water is extracellular? How it is divided?

Answer 14

1/3

Intravascular and extravascular

Question 15

What is the normal range for K?

Answer 15

3.5-5mmol/L

Question 16

High plasma sodium indicates what?

Answer 16

Decreased water intake

Increase water loss - sweating, urination