L3 | Fluids And Electrolyets

Question 1

How is fluid divided in our bodies?

Answer 1

TBW is around 60%.

• 40% is intracellular
• 20% is extracellular:
  A. 15% is interstitial
  B. 5% is intravascular

Question 2

What are electrolytes?

Answer 2

Electrolytes are compounds that separate into ions when dissolved in water, thus electrolytes carry a charge when in solution.

They are measured in milliequivalents of an ion in a liter of solution.

E.g.
Na - 138-145 mEq/L
Cl - 98 - 107 mEq/L
K - 3.3 - 4.5 mEq/L

Question 3

What are the main fluid types?

Answer 3

1. Crystalloids: are solutions that contain mineral salts and small, water soluble molecules. They’re cheap and they provide an easy and convenient way to resuscitate fluids. They can however result in edema.
2. Colloids: are gelatinous solutions that contain larger molecules that stay in the blood stream which maintains a high osmotic pressure. They’re costly but they provide a swift shift of fluid between different compartments and have relatively low risks of edema.

Question 4

How are crystalloids classified?

Answer 4

They’re classified according to their tonicity (their resemblance to the body’s own plasma concentrations) into:
1. Hypotonic fluids: solutions that contain a lower concentration of molecules when compared to body fluids, therefore it causes fluid to shift intracellulary which causes the cells to swell, e.g. 0.5% saline, 0.255% saline and 0.35% saline

2. Isotonic fluids: solutions that contain similar concentrations of molecules when compared to body fluids, therefore it doesn’t cause any fluid shifting, e.g. 0.9% saline (normal saline), LR, D5W
3. Hypertonic fluids: solutions that contain higher concentrations of molecules when compared to body fluids, therefor it causes fluids to shift intravascularly (causes cells to shrink) e.g. 3% and 5% saline, D10W, D5Saline, D5LR

Question 5

What are the indications and contraindications of plasma?

Answer 5

Indications: they can be used without delay (cross-matching is unnecessary in:
1. Burn patients who suffer from protein loss
2. COVID-19 patients, the idea is that the plasma of patients who have recovered might contain AB’s to the virus which can be utilized by the recipients who currently have the disease.

Contraindications:
1. Absolute CI: patients with congenital IgA deficiency due to anti-IgA
2. Relative CI: heart failure and pulmonary edema

Question 6

What are the indications and contraindications of dextrose 5%

Answer 6

Indications: used in early postoperative periods to provide calories with no electrolytes

Contraindications: sensitivity to the drug

Question 7

What are the indications and contraindications of normal saline?

Answer 7

Indications: used when Na is depleted from the body due to vomiting or by gastric, duodenal, or intestinal operations or alimentary fistulas, or hemorrhages of all sorts.

Contraindications: CHF, severe renal impairment, salt retention, edematous states and liver cirrhosis

Question 8

What are the indications and contraindications of LR (hartman’s solution)?

Answer 8

Components: a mixture of sodium, potassium and calcium chloride, and sodium lactate (as opposed to sodium bicarbonate in non-lactated ringers)

Indication: replacing fluid and electrolytes in patients with low blood volume or hypotension.

Contraindication: metabolic acidosis or alkalosis, severe liver disease and DM