Colloids And Crystalooids

Prepared by: Sondos Shalabi

Supervised by: Dr. Osama Attallah

Intravenous therapy

the infusion of liquid substances directly into a vein.

Substances that may be infused: volume expanders

Crystalloids colloids

blood-based products blood substitutes Buffer solutions Medications nutrition.

Volume expander

a type of IV therapy that has the function of:

1. providing volume2. may be used for fluid replacement.

Two main types: Crystalloids : aqueous solutions of mineral

salts or other water-soluble molecules. Colloids: IV fluids that contain solutes in

the form of large proteins or other similarly sized molecules.

Colloids

Don’t pass through diffusional membranes. Stay,,preserve a high colloid osmotic pressure in

the blood. Attract water from cells. preferentially increase the intravascular volume.

crystalloids also increase the interstitial volume and intracellular volume.

Eg:5% albumin, gives plasma expansion nearly twice that produced by an equivalent volume of isotonic saline

This the benefit: more effective volume resuscitation.

Colloid osmotic pressure

Oncotic pressure. Osmotic pressure or hydrostatic.

the ability of each fluid to expand the plasma volume is directly related to the COP

COP of plasma=25mmHg If > ,, plasma volume expansion exceeds the

infused volume Transient volume expansion May worsen edema in severe hemorrhagic shock

Expensive have specific storage requirements have a short shelf life

Types:

Albumin dextrans Hetastarch gelatins

Albumin

A transport protein that is responsible for 75% of COP.

Heat sterilized pooled human plasma.

5% solution (50 g/L) 25% solution(250 g/L), the salt poor

albumin

Features

A 5% albumin COP 20 mm Hg similar in oncotic activity to plasma “isotonic” Approximately half of the infused volume stays in the

vascular space. The oncotic effects of albumin last 12 to 18 hours.

25% albumin COP of 70 mm Hg Hypertonic expands the plasma volume by 4 to 5 times the volume

infused This plasma volume expansion occurs at the expense

of the interstitial fluid volume so 25% albumin should not be used for volume

resuscitation in hypovolemia. shifting fluid from the interstitial space to the vascular space

Disadvantages

Allergic reactions-rare Cogulopathies- dilutional Induce renal failure Impair pulmonary function

In hemorrhagic shock

The Dextrans

glucose polymers produced by a bacterium incubated in a sucrose medium

First introduced in the 1940s these colloids are not popular because

of the perceived risk of adverse reactions. 10% dextran-40 6% dextran-70 both diluted in isotonic saline.

Features

hyperoncotic to plasma (COP = 40 mm Hg).

Dextran-40 causes a larger increase in plasma volume than dextran-70

but the effects last only a few hours.

Dextran-70 is the preferred preparation because of its prolonged action.

Initial volume expansion Reduce blood viscosity

Disadvantages

a dose-related bleeding tendency inhibiting platelet aggregation reducing activation of Factor VIII promoting fibrinolysis.

Anaphylactic reactions -5% of patients coat the surface of red blood cells

interfere with the ability to cross-match blood Must wash it

increase the erythrocyte sedimentation rate acute renal failure

hyperoncotic state with reduced filtration pressure

Hydroxyethyl starch

produced by the hydrolysis of insoluble amylopectin.

substitutions of hydroxyl groups for carbon groups on glucose molecules.

Molecular weight from 1000-3,000,000 Hexa-starch Penta-starch Hextend

Hexastarch

6% solution in isotonic saline. Molecular weight similar to albumin. colloid effects are equivalent to those of

5% albumin. cheaper than albumin

Disadvantages

Coagulopathies decreases in von Willebrand's factor and factor

VIII:c postoperative bleeding in cardiac and

neurosurgery patients. can induce renal dysfunction hyperchloremic acidosis -high chloride content cleaved by serum amylase enzymes

Hyperamylasemia not pancreatitis Check lipase

Anaphylactic reactions

Hextend

modified, balanced, high molecular weight

suspended in a lactate-buffered solution No Coagulopathies. hemodilution

Gelatins

produced from bovine collagen.

urea-linked gelatin succinylated gelatin

(modified fluid gelatin, Gelofusine). coagulopathies

Crystalloids

Crystalloids

The primary fluid used for prehospital IV therapy

contain electrolytes (e.g., Na, K, Ca, Cl) Pass readily through membranes. principal component is NaCl. NaCl predominant solute in ECF

Plasma Interstitium 75-80%

predominant effect of volume resuscitation with crystalloid fluids is to expand the interstitial volume rather than the plasma volume.

Eg:

infusion of 1 L of 0.9% sodium chloride (isotonic saline)

adds 275 mL to the plasma volume and 825 mL to the interstitial volume.

=1100 mL is slightly greater than the infused volume

fluid shift from the intracellular to extracellular space.

isotonic saline is actually hypertonic to ECF

classified according to their “tonicity.” Isotonic Hypertonic Hypotonic

low blood volume cellular dehydration

Isotonic saline

Prototype 0.9% sodium chloride (NaCl) in sterile water 9 g NaCl per liter. pH slightly lower than plasma

No clinical significance Cl content higher than plasma

Risk of hyperchloremic metabolic acidosis To correct volume deficits associated with

hyponatremia, hypochloremia and metabolic alkalosis.

pH=4.5 - 7

Lactated Ringer’s

isotonic crystalloid contains

sodium chloride potassium chloride calcium chloride sodium lactate

Hartmann’s solution

in sterile water.

lactate (28 mEq/L)Less Na, Cl than normal salineNo proven buffering action of lactate No proven benefit over normal saline

Disadvantages

activates the inflammatory respons induces apoptosis.

D isomer of lactate The Ca can bind to certain drugs and

reduce their bioavailability and efficacy. Also bind to citrated anticoagulant in

blood products. formation of clots in donor blood.

lactated Ringer’s solution is contraindicated as a diluent for blood transfusions.

5% Dextrose in water

(D5W) is packaged isotonic carbohydrate solution

Glucose is the solute. not an effective volume expander intended to supply calories obsolete 50 g dextrose per liter provides 170 kcal per liter Osmolality 253 mOsml

Disadvantages

once D5W enters the body, the cells rapidly consume glucose.

This leaves primarily water IV fluid hypotonic in relation to the plasma an osmotic shift of water into the cells.

addition of dextrose to intravenous fluids increases osmolarity

creates a hypertonic infusion If glucose use is impaired (critically ill patients)

osmotic force cell dehydration.

enhanced lactate production (critically ill patients)

Normosol

Contents of Normosol: Na = 140 mEq/L

Cl = 98 mEq/LK = 4 mEq/LMg = 3 mEq/LAcetate = 27 mEq/LGluconate = 23 mEq/LPH =6.6

added buffer capacity pH that is equivalent to that of plasma addition of magnesium

magnesium depletion in hospitalized patients.

When to use which??

fluid selection depends on: the estimated fluid loss the primary fluid compartment involved the patient's underlying problem the physiological and hemodynamic impact

of the IV solution.

When to use which?? Crystalloids the early popularity of crystalloid fluid resuscitation

in hypovolemia stems from two observations: the response to mild hemorrhage,

which involves a shift of fluid from the interstitial space to the vascular space.

from studies in an animal model of hemorrhagic shock survival improved if a crystalloid fluid was given along

with reinfusion of the shed blood volume. hemorrhage is an interstitial fluid deficit “mild

hemorrhage” replacement of interstitial fluid with crystalloid fluids is important

for survival.

When to use which?? Colloids If blood loss is more severe the priority is to keep the vascular space filled

and thereby support the cardiac output. colloid fluids are more effective

colloid fluids are about three times more potent than crystalloid fluids for increasing vascular volume and supporting the cardiac output

Crystalloid resuscitation can achieve the same endpoint larger volumes are needed “3 times”

Survival in hemorrhagic shock Colloids no higher rate despite superiority in volume

expansion Some studies- increased mortality

Expense Colloids higher expense

Edema crystalloid -expected feature

fluids distribute primarily in the interstitial space Colloid- risk

If permeability is disrupted Eventually albumin finds its way to interstitium some how

THANK YOU!