IV Fluids

Question 1

Difference between osmolality and osmolarity

Answer 1

Osmolality: measured directly
Osmolarity: calculated bedside

Question 2

Osmolality of ECF

Answer 2

285-295 mOsm/L

Question 3

Compared to the osmolality of ECF, is the osmolality of lactated ringer hyper or hypotonic?

Answer 3

Slightly hypotonic at 273 mOsm/L

ECF: 285-295 mOsm/L

Question 4

Compared to the osmolality of ECF, is the osmolality of normal saline (0.9% NaCl) hyper or hypotonic?

Answer 4

Slightly hypertonic at 308 mOsm/L

ECF: 285-295 mOsm/L

Question 5

Which IV solutions include buffer? What are their pHs?

Answer 5

Lactated ringer - pH: 6.5
The lactate is metabolized to bicarb by the liver.

Plasma-lyte - pH: 7.4
Includes acetate and gluconate

Question 6

Compared to the osmolality of ECF, is the osmolality of 0.45% NaCl hyper or hypotonic?

Answer 6

Very hypotonic at 154 mOsm/L

ECF: 285-295 mOsm/L

Question 7

You want to deliver a rapid bolus of fluids, nurse asks what kind of line you want. If you want it delivered faster, what kind of line do you use? If you want it delivered slower, what kind of line do you use?

Answer 7

Faster flow rate = shorter and fatter line

Slower flow rate = longer and shorter line

Question 8

Crystalloid IVF includes what types?

Answer 8

Saline
Lactated ringers
Plasma-lyte

Question 9

Colloid IVF includes what types?

Answer 9

Albumin

Hetastarch

Question 10

A patient comes in with volume depletion, what is your first course of action?

Answer 10

Bolus with an isotonic solution, such as lactated ringer or normal saline (0.9% NaCl)

Question 11

If a patient comes in with volume depletion and is NPO, what must you give them?

Answer 11

Bolus with an isotonic solution, such as lactated ringer or normal saline (0.9% NaCl) + D5W +/- K+

Question 12

A patient presents with sepsis. What is your first line of management?

Answer 12

Bolus with lactated ringer or normal saline 30mL/kg for the first 3 hours.

Question 13

A patient presents with hyperglycemia. What is your first line of management?

Answer 13

Resuscitate with normal saline 30-40 mL/kg until labs return.

Insulin + crystalloid + electrolytes +/- dextrose

Question 14

A patient comes in with severe, symptomatic depletion from GI/renal losses. What is your first line of management?

Answer 14

30 mL/kg bolus, BUT be sure to know electrolytes ASAP.

Question 15

A patient comes in with hypokalemia. What must you do first?

Answer 15

Replace Mg levels first, then replace K+ levels.

Question 16

What is the 4-2-1 rule? In what situations would you use the 4-2-1 rule?

Answer 16

The 4-2-1 rule is used in maintenance fluids.

4 mL/kg/hr for the first 10 kg of weight

2 mL/kg/hr for the next 10 kg of weight

1 mL/kg/hr for each kilogram thereafter.

Question 17

A patient comes in with volume depletion. He also has CHF. How would you manage?

Answer 17

Small, slow boluses!

Reassess

Look for volume overload: SOB, crackles, increased O2 requirement, rales, edematous

Admit for slow volume repletion

Positive pressure ventilation