Various Colloidal Solutions: Indications

Crystalloids Vs. Colloids

Presenter: Dr. Suresh PradhanModerator: Dr. Yogesh Dhakal

Solution Suspension Colloid

Appearance Clear, transparent and homogeneous

Cloudy, heterogeneous, at least two substances visible

Cloudy but uniform and homogeneous

Particle Size molecule in size larger than 10,000 Angstroms 10-1000 Angstroms

Effect of LightTyndall Effect

none -- light passes through, particles do not reflect light

variable light is dispersed by colloidal particles

Effect of Sedimentation none particles will eventually

settle out none

Colloid• are homogenous, non-crystalline substances

consisting of large molecules which persist in the vascular compartment to expand the functional plasma volume (lasting several hours to several days)

• 1ml blood= 1ml colloid= 3ml of crystalloid

Indications1. Fluid resuscitation in patients with severe

intravascular fluid deficits (e.g. hemorrhagic shock) prior to arrival of blood for transfusion

2. Fluid resuscitation in the presence of severe hypoalbuminemia or conditions associated with large protein losses such as burns

Classification

COLLOIDS

BLOOD DERIVED

ALBUMIN 5% & 25%

PLASMA PROTEIN FRACTION

Both α & β globulins + albumin

SYNTHETIC GLUCOSE POLYMER

DEXTROSE dextran 40/70

STARCHES hetastarch, pentastarch

GELATIN associated with histamine

mediated allergic rxns

Most frequently used ColloidsFluid Weight (Average

Molecular Weight)kD

Colloid Osmotic mmHg

5% Albumin 69 20

25% Albumin 69 70

Plasma 119 25

6% Hetastarch 450 30

10% Pentastarch 264 40

10% Dextran 40 40 148

6% Dextran 70 70 60

Intravenous Albumin

5% (250-mL and 500- mL vials) and 25% (50-mL and 100-mL vials)

• derived from human serum albumin and have been pasteurized at 140°F (60°C) for 10 hours– removes the hazard of transmission of viral diseases• contain no clinically important antibodies and may

be administered without regard to the recipient’s blood group or Rh factor• Commercially available albumin-5%, 20% and 25%

• Preparations contains sodium caprylate, acetyltryptophanate or both as stabilizers allowing storage for 3 years • commercial albumin products contain 130–160

mEq of sodium per liter of solution• possesses potential free radical scavenging

characteristics and is the principal IV source of reduced sulfhydryl groups

• 5% solution is isotonic with respect to human plasma, have COP of about 20mmHg (near-normal COP)• used when crystalloids fail to sustain the plasma

volume for more than few minutes because of low COP• most appropriate when there is abnormal loss of

protein from the vascular space e.g. peritonitis or extensive burns

• 25% albumin contains purified albumin 5X the normal concentration• Potential to expand the plasma volume by up to 5

times the volume provided.• 1ml of 25% albumin administered will draw 3-4L of

fluid from the interstitial space into IV space • hence not recommended in cardiac failure or in presence

of anemia

• has a very low incidence of allergic reactions (0.5–1%) and these are usually mild (rash, fever, chills, nausea)

Rate of infusion:• adults- initial infusion of 25gm• 1-2ml/min-5% albumin• 1ml/min- 25% albumin

Indications• Plasma volume expansion in acute hypovolemic

shock, burns, severe hypoalbuminemia• Hypoproteinemia- liver disease, diuretic resistant

nephrotic syndrome• Treatment of hyperbilirubinemia: exchange

transfusions; albumin binds to the bilirubin

Contraindications• Severe anemia, cardiac failure• Hypersensitive reactions

ADVANTAGE• Natural• Higher degree of volume expansion• Antioxidant and scavenging effects

DISADVANTAGE• Expensive• Volume overload

Plasma Protein Fraction• 5% pooled solution of stabilized human plasma

proteins in saline containing at least 83% albumin and no more than 17% globulins

Clinical uses• treatment of hypovolemic shock and to provide

protein to patients with hypoproteinemia• effective for the initial treatment of shock in

infants and children with dehydration, hemoconcentration and electrolyte deficiency caused by diarrhea (20-30ml/kg IV)

Limitations• High cost• Limited availability• Hypotension- presence of perkallikrein activator ---

leads to production of bradykinin--- peripheral vasodilation

Dextran• water soluble glucose polymer• produced by using the bacterial enzyme dextran

sucrase from the bacterium Leuconostoc mesenteroides (B512 strain) growing in a sucrose medium

• 10% Dextran 40 (MW 40kD) and 6% Dextran 70 (MW 70kD)

• ultimately degraded to glucose• mostly used for improving microcirculation

•particles weighing less than 15 kD are rapidly filtered and not reabsorbed•the threshold for the renal excretion of dextran is a molecular weight of roughly 55 kD, therefore more dextran 40 than dextran 70 is renally excreted•the remainder are excreted through the gut or phagocytosed by cells of the reticuloendothelial system

Clinical Uses• Suitable alternative for blood or plasma for

expansion of IV volume• Dose: • Adult patient in shock – rapid 500 ml iv infusion• 20ml/kg IV during first 24hrs and 10ml/kg in subsequent

days

• therapy not to be continued more than 5 days• Special solution of 32% dextran 70 used in

hysteroscopy

• Dextran 70 is a better volume expander and has longer duration of action 12hrs than dextran 40 (6hrs)• dextran 40 is more useful clinically because it

improves blood flow through the microcirculation, presumably by decreasing blood viscosity• Dextran 40 is used in vascular surgery to prevent

postoperative thromboembolism and as a prophylaxis of DVT

Adverse Effects• Allergic reactions 1 in every 3,300 administrations-

caused by circulating dextran reactive IgG antibodies that is present in most adults• Increased bleeding time caused by decreased

platelet adhesiveness at doses 20ml/kg/hr• Rouleaux formation (interfering with cross

matching with blood) so blood for cross-matching should be sent before dextran infusions

• Non cardiogenic pulmonary edema, a rare case; thought to be a direct toxic effect on pulmonary capillaries after intravascular absorption• Hyper-oncotic state with reduced filtration pressure

leading to renal failure– unproven; Dextran 40 can produce highly viscous urine that may actually obstruct the renal tubules and cause acute renal failure

Precautions/ CI• Severe olio/anuria• Congestive heart failure, circulatory overload• Bleeding disorders like thrombocytopenia• Anticoagulant effect of heparin is enhanced• Hypersensitive to dextran

Hydroxyethyl starches (HES)

• modified natural polysaccharides, derived from amylopectin, that structurally resemble glycogen• solutions of starch are unstable as they are rapidly

hydrolyzed by α-amylase• solution is stabilized by hydroxylethylation• this results in hydroxyethyl substitutions,

predominantly at carbon 2 (c2), but also at c3 and c6, in the glucose ring

• After infusion of hetastarch the dispersion of molecular weights changes: first the small molecules are rapidly eliminated, then the large molecules are partially hydrolyzed to middle-size molecules. • main route of elimination-urinary• a fraction is taken up by the reticuloendothelial

system from where it is slowly eliminated

Three classes by their weight-averaged molecular weight:1.high molecular weight (450–480 kDa), 2.medium molecular weight (approximately 200 kDa), 3.low molecular weight (70–130 kDa)

Examples of commercially available starches are:1.6% high-molecular- weight hetastarch in saline

(Hespan),2.6% high-molecular-weight hetastarch in balanced

electrolytes (Hextend)above two are used exclusively in US

medium-molecular-weight pentastarch in saline (Pentaspan, EloHAES, HAES- steril, Hestar-200)- popular fluid in other countriesand low-molecular-weight tetrastarch in saline (Voluven)

Pentastarch• LMW derivative

(2,64,000) 3%, 6% and 10% solution• Lower degree of

esterification• Lesser effect on

coagulation• 10% solution can

increase plasma volume 1.5 times of infused volume

Advantages:• Non antigenic• Doesn’t interfere with blood grouping• Greater plasma volume expansion• Preserve intestinal microvascular perfusion in

endotoxemia• Duration – 24 hrs

Disadvantages:• increase in Serum amylase concentration upto 5

days after discontinuation• affects coagulation by prolonging PTT and aPTT, BT

by lowering fibrinogen • decreased plasma aggregation, VWF, factor VIII

Contraindications :• Bleeding disorders , CHF• Impaired renal function

Administration :• Adult dose 6% solution – 500ml to 1 lit• Total daily dose should not exceed 20ml/kg

Gelatins ( Hemaccel, Gelofusin)

• derived from hydrolysis of bovine collagen• gelatins are medium-size compounds, with a

molecular weight of 30– 40 kD • are approximately isotonic

• two most common preparations are • succinylated gelatin MW 30 kD e.g. Gelofusin,

presented in a carrier solution of Na 154 mmol and Cl 120 mmol, • urea-linked gelatin (Hemaccel ), presented in a

carrier solution of isotonic saline plus K 5.1 mmol and Ca 6.25 mmol/L

• metabolism is in liver and completely eliminated by kidneys resulting in osmotic diuresis, but may also be broken down by proteases in the RES

Indications:• Rapid plasma volume expansion in hypovolemia• Volume pre-loading • Priming of heart lung machines

Advantages:• coagulation problem is unlikely• remains in blood for 4-5 hours• Infusion of 1000ml expands plasma volume by 300-

350mlAdverse Effects:• incidence of allergic reactions is relatively high

compared with hydroxyethyl starches• gelatin induced histamine release has been

associated with hypotension, bronchospasm and cutaneous rashes

S.N. CRYSTALLOIDS COLLOIDS

1 Crystalline substanceLow molecular weight

Non-crystalline substanceHigh molecular weight

2 Rapidly distributes throughout the entire extravascular space

Most part remain intravascular

3 Expands the interstitial volume rather than the plasma volume

Maintain plasma oncotic pressureEffective in restoring IV volume and CO3X more effective in increasing plasma volume

4 1ml blood =3ml crystalloid 1ml blood=1ml colloid smaller infused volume

5 IV half life is 20-30mins Half life is 3-6hrs

6 Cheap Expensive limits their use

7 Disadvantages: transient increase in IV volume, hemodynamic improvement, peripheral edema(protein dilution) and pulmonary edema (protein dilution plus pulmonary arterial occlusion pressure)

Disadvantages: coagulopathy Dextran> Hestarch, pulmonary edema in capillary leak states, decreased GFR, osmotic diuresis with LMW dextran, greater duration of excessive volume expansion

Generalization • Crystalloids when given in sufficient amounts are

as effective as colloids in restoring IV volume• Replacing with crystalloids requires 3-4 times the

volume needed using colloids• Severe IV deficit can be more rapidly corrected

using colloid solutions

• In rapid major blood loss either type of fluid is suitable to maintain organ perfusion in the short term.• For ongoing losses colloids offer faster, longer

lasting resuscitation with less volume of infusion• Rapid administration of large amounts of

crystalloids >4-5 L is more frequently associated with significant tissue edema--- marked tissue edema can impair oxygen transport---tissue healing and return of bowel function

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