IV Fluids Composition

Question 1

Explain Dextrose fluid

Answer 1

Hypotonic with only dextrose and water.

Only 7% of the fluid stays in the intra-vascular space (5% dextrose has no role in fluid resus) only in fluid maintenance regimes.

Question 2

Main advantage of dextrose

Answer 2

Being able to maintain hydration without disrupting electrolyte balance

It can also be prescribed with supplementary potassium.

Question 3

Explain Normal Saline

Answer 3

Isotonic solution with Na+, Cl- and water.

25% goes intra-vascular which makes it useful for both resus and maintenance.

Potassium can be added as well

Question 4

Why should Normal saline not be used as a lone fluid maintenance?

Answer 4

Excessive saline replacement can cause hyperchloraemic acidosis

Question 5

Explain Hartmann’s solution

Answer 5

A balanced isotonic solution with Na+, Cl-, HCO3- as lactate, Ca2+ and water.

It distributes similarly as normal saline making it useful for both resus and fluid maintenance.

Question 6

Advantages of Hartmann’s solution

Answer 6

More physiological than normal saline similar to plasma.

It also contains lactate, which it uses to generate alkalising HCO3-

Question 7

Can Hartmann’s be used in severe acidosis?

Answer 7

Yes, it’s lactate in Hartmann’s and not lactic acid.

Hartmann’s contain lactate to generate alkalising HCO3-, means it can even aid in reducing the risk of acidosis.

Question 8

What are colloids?

Answer 8

Rarely used

Proteins with large molecular weights aiming to maintain a high plasma oncotic pressure to keep fluid within the intravascular compartment.

Studies have shown limited benefit in resus and also come with a small risk of anaphylaxis.

Question 9

Types of colloids

Answer 9

Human albumin solution can be used for patients who are unable to produce sufficient protein.