Fluids

Question 1

Define tonicity

Answer 1

• effective osmoles in solution
• solutes that cannot freely cross membranes (Na+ and K+) determines the pressure gradient between two solutions separated by a semi-permeable membrane.

Question 2

What are the contents of plasma?

Answer 2

• 95% water
• contains everything except RBC and WBC
• includes clotting factors

Question 3

What is serum?

Answer 3

• portion of whole blood that isn’t RBC or WBC or clotting factor
• includes proteins, electrolytes, antibodies, hormones and drugs

Question 4

In general, total body water is how much of total body weight?

Answer 4

60% of total body weight in kg

Question 5

The ICF is made up of what electrolyte concentrations in normal conditions?

Answer 5

Na:   25mEq/L
K: 150 mEq/L
Cl:  5 mEq/L
Ca:  0.04 mg/dL
HCO3:  6 mEq/L

Question 6

The ECF is made up of what electrolyte concentrations in normal conditions?

Answer 6

Na: 140 mEq/L
K:  4mEq/L
Cl: 100 mEq/L
Ca: 9mEq/L 
HCO3: 24 mEq/L

Question 7

What is the normal tonicity between ICF and ECF?

Answer 7

280mOsm/L

Question 8

Equation to calculate Serum Osmolality (mOsm/kg)

Answer 8

2Na+ glucose/18+ BUN/2.8

Question 9

Which glands tightly regulate serum osmolality in the body?

Answer 9

hypothalamus-pituitary

-through the release of arginine vasopressin (AVP) also known as antidiuretic hormone (ADH)

Question 10

Describe the physical characteristics of hypovolemic volume status

Answer 10

• Hypotension
• Tachycardia
• Poor skin turgor
• slow capillary refill time

Question 11

Describe the physical characteristics of hypervolemic volume status

Answer 11

• hypertension
• edema (peripheral and/or pulmonary)
• weight gain
• jugular venous distention

Question 12

What do balanced crystalloids mimic?

Answer 12

plasma electrolyte concentrations

Question 13

What are two balanced crystalloids?

Answer 13

• Lactated Ringers

- Plasma-Lyte A

Question 14

True or false: If you give IV isotonic fluid it won’t stay in the extracellular fluid space.

Answer 14

FALSE

-You are not changing the tonicity of the system so it is going to stay in extracellular space (no fluid will shift)

Question 15

True or false: If you give IV hypotonic fluid it will shift water into the intracellular space.

Answer 15

TRUE
-If you give a solution lower than plasma tonicity, it will cause a fluid shift into the intracellular space to balance out

Question 16

True or false: If you give IV hypertonic fluid it will pull water out of the intracellular space.

Answer 16

TRUE

-this is increasing the tonicity of the extracellular space

Question 17

Is dextrose 5% in water (D5W) free water?

Answer 17

YES