Type of Fluids and Volume ExpanderNabilah 060 100 814H4

Body Fluids Composition

Total body water= 60% (male)|50%(female) x body wt

= 0.5 X 70 = 35 liters

ECF=1/3

0.33 X 35 = 11.6 liters

ICF=2/3

0.66 X 35 = 23.3 liters

Blood=1/4 (ECF)

0.25 X 10.5 = 2.625 liters

Types of IV Fluids

Three main types of IVF:Isotonic fluidsHypotonic fluidsHypertonic Fluids

Isotonic Fluids

Osmolarity is similar to that of serum.These fluids remain intravascularly

mommentarily, thus expanding the volume.Helpful with patients who are hypotensive

or hypovolemic.Risk of fluid overloading exists. Therefore,

be careful in patients with left ventricular dysfunction, history of CHF or hypertension.

Total body water

ECF=1 liter ICF=0

Intravascular

=1/4 ECF=250 ml

1 Liter 0.9% saline

Interstitial=3/4 of ECF=750ml

Hypotonic FluidsLess osmolarity than serum (meaning: less

sodium ion concentration than serum)These fluids DILUTE serum thus decreasing

osmolarity.Water moves from the vascular compartment into

the interstitial fluid compartment interstitial fluid becomes diluted osmolarity decreases water is drawn into adjacent cells.

Less than 10% remain intravascular, inadequate for fluid resuscitation

Caution with use because sudden fluid shifts from the intravascular space to cells can cause cardiovascular collapse and increased ICP in certain patients.

1 liter 5% Dextose

Total body water=1 liter

ECF=1/3 = 300ml ICF=2/3 = 700ml

Intravascular

=1/4 of ECF~75ml

Hypertonic FluidsThese have a higher osmolarity than

serum.These fluids pull fluid and sometimes

electrolytes from the intracellular/interstitial compartments into the intravascular compartments.

Useful for stabilizing blood pressure, increasing urine output, correcting hypotonic hyponatremia and decreasing edema.

These can be dangerous in the setting of cell dehydration.

1 liter 5% Albumin

Intravascular=1 liter

Two Main Groups of FluidsCrystalloidsColloids

Crystalloids

Clear solutions –fluids- made up of water & electrolyte solutions; small molecules.

These fluids are good for volume expansion.However, both water & electrolytes will cross a

semi-permeable membrane into the interstitial space and achieve equilibrium in 2-3 hours.

Remember: 3mL of isotonic crystalloid solution are needed to replace 1mL of patient blood.

This is because approximately 2/3rds of the solution will leave the vascular space in approx. 1 hour.

Crystalloids Continued

Advantages: ◦ Inexpensive ◦Easy to store with long shelf life ◦Readily available with a very low incidence of

adverse reactions◦Variety of formulations available that are effective

for use as replacement fluids or maintenance fluidsA major disadvantage is that it takes

approximately 2-3 x volume of a crystalloid to cause the same intravascular expansion as a single volume of colloid.

ColloidsColloids are large molecular weight solutions

(nominally MW > 30,000 Daltons)Macromolecular substances made of gelatinous

solutions which have particles suspended in solution and do NOT readily cross semi-permeable membranes or form sediments.

Their high osmolarity, are important in capillary fluid dynamics because they are the only constituents which are effective at exerting an osmotic force across the wall of the capillaries.

These work well in reducing edema draw fluid from the interstitial and intracellular compartments into the vascular compartments.

Initially these fluids stay almost entirely in the intravascular space for a prolonged period of time compared to crystalloids.

Colloids Continued

The general problems with colloid solutions are:Much higher cost than crystalloid solutions Small but significant incidence of adverse

reactions Gelatinous properties cause platelet

dysfunction and interfere with fibrinolysis and coagulation factors thus possibly causing Coagulopathy in large volumes.

These fluids can cause dramatic fluid shifts which can be dangerous if they are not administered in a controlled setting.

Solutions

Volumes

Na+ K+ Ca2+ Mg2+ Cl- HCO3- Dextrose mOsm/L

ECF 142 4 5 103 27 280-310

Lactated Ringer’s

130 4 3 109 28 273

0.9% NaCl

154 154 308

0.45% NaCl

77 77 154

D5W 50

D5/0.45% NaCl

77 77 50 406

3% NaCl 513 513 1026

6% Hetastarch

500 154 154 310

5% Albumin

250,500130-160

<2.5130-160

330

25% Albumin

20,50,100

130-160

<2.5130-160

330

Common parenteral fluid therapy