Plasma expanders.pptx

Pharmacology Plasma Expanders

1. Plasma Expanders Dr KG Bandekar MD Pharmacology

2. Body fluid compartments

3. Plasma Vs Serum Plasma Plasma is blood devoid of blood cells. Serum Plasma without clotting factors

4. Volume expanders Intravenous fluids that are used to increase or retain the volume of fluid in the circulating blood Used to replace fluids that are lost due to illness, trauma or surgery. Do not carry oxygen

5. Ideal properties Iso-oncotic with plasma Distributed to intravascular compartment only Pharmacodynamically inert Non- pyrogenic & non antigenic Should not interfere with blood grouping or cross matching Stable, easily sterilizable and cheap

6. Types of volume expanders Crystalloids : aqueous solutions of mineral salts or other water soluble molecules. Normal saline (NS) Dextrose Ringer’s solution (RL) Colloids : Larger insoluble molecules Dextran Human albumin Gelatin

7. Colloids Vs Crystalloids in volume expansion Colloids are better than Crystalloids because: Being large molecules retained in the intravascular space increase osmotic pressure more effective resuscitation Duration of action is relatively longer

8. Colloids

9. Colloids Human albumin Dextrans Degraded gelatin polymer ( Polygeline ).. Hemaccel Hydroxy ethyl starch …HES..( Hetastarch ) and… Blood

10. Mechanism of action : Colloids Principle of osmosis Increases Plasma osmotic pressure , draws water into plasma from interstitial fluid

11. Osmosis

12. Osmosis

13. 1. Human Albumin Most abundant protein in human plasma Hydrophilic Accounts for 70% to 80% of the plasma colloid oncotic pressure (COP) Binds to cations , anions, and toxins, such as bilirubin , gives it an important physiological role in buffering the acid-base balance of the blood, transporting proteins and drugs. Synthesized in the liver

14. Human Albumin Obtained from pooled human plasma. Can be used without regard to patient’s blood group and doesn’t interfere with coagulation/ platelet fn . It is free of risk of transmission of hepatitis because the preparation is heat treated. Expensive

15. Indications : Albumin Rapid volume expansion is req Hyopoproteinemia – Liver dis / nephrotic syndrome

16. ADR : Albumin Rare

17. 2. Dextrans Glucose polymers ..(found in beet root) Obtained by the action of the bacterium Leucohostoc mesenteroides

18. Dextrans Can be stored for 10 years and are cheap

19. Types of Dextrans Dextran 40 (10% solution) Dextran 70 (6% solution) Molecular weight is the main factor for effects

20. (a) 6% Dextran 70 It is most commonly used preparation. It expands plasma volume for nearly 24 hrs. Excreted slowly by glomerular filtration over weeks Gets deposited in reticulo - endothelial cells

21. 6 % Dextran 70 Nearly all the properties of an ideal plasma except : It may interfere with blood grouping and cross matching. It can interfere with coagulation and platelet function and thus prolong bleeding time Some polysaccharide reacting antibodies, if present, may cross react with dextran and trigger anaphylactic reaction like Urticaria , itching, bronchospasm

22. (b) 10 % Dextran 40 Faster acting than 6 % dextran 70 More volume expansion than 6 % dextran 70 Reduces blood viscosity Excreted through renal tubules and occasionally may produce acute renal failure .

23. Contraindications : Dextrans ARF Hypersensitivity CHF Bleeding disorders

24. 3. Degraded gelatin polymer ( polygeline )…. hemaccel Synthetic polymer (polypeptide) Doesn’t interfere with blood grouping and cross matching Non-antigenic More expensive than dextran ( e.g : Haemaccel )

25. Indications : Gelatin polymers Rapid correction of intravascular vol Prophylactic – before major surg

26. 4. Hydroxy ethyl starch (HES) ( Hetastarch ) Complex mixture of ethoxylated amylopectin of various molecular sizes No RF or coagulation disturbances

27. Advantages : HES Non antigenic No interference with bld grouping No interference with coagulation / platelet action Do not interfere with renal fn Less expensive than 5 % Albumin Longer duration of action ….~ 24 hrs

28. Disadvantages : HES Increases S. amylase levels for 4-5 days

29. Imp ADR : Colloids Dextran , HMW starch have negative impact on coagulation May induce acute renal failure, allergy.

30. Colloids Not causing Bleeding / antigenicity Human Albumin Degraded gelatin polymer … hemaccel HES Causing Bleeding / antigenicity ???? Dextrans

31. Crystalloids

32. Crystalloids Electrolyte solutions with small molecules that can diffuse freely throughout the extracellular space 75-80% of infused crystalloid is distributed in interstitial space Expands interstitial volume rather than plasma volume Minimal impact on intracellular volume .

33. Types of Crystalloids Isotonic: Isotonic to plasma NS Ringer’s Lactate Hypotonic Hypertonic

34. Composition Fluid Na+ Cl - K+ Ca+ pH Glucose Osmolarity Tonicity Use Plasma 142 108 4.2 1.3 7.4 ~ 0.85 ~ 290 - - NS 154 154 5.7 308 Isotonic Resuscitation RL 130 109 4 3 6.4 273 Isotonic -do- D5 50 252 Hypotonic i ) Na+ ii) Hypo glycemia

35. NS 1 liter NS ….9 grams NaCl (154 mEq Na) 650ml of NS provides…~ 5.9 gram NaCl (100 mEq Na) ( Daily req of Na ~ 5.9 grams) No glucose ---- use in DKA

36. NS NaCl is mainly extracellular….(physiology) NS is used to provide extracellular electrolytes

37. NS: When to be given? Shock: fluid volume deficit (hemorrhage, Severe vomiting or diarrhea, Mild hyponatremia 3) Metabolic acidosis ( eg . diabetic ketoacidosis ) 4) Fluid of choice for resuscitation efforts 5) Only fluid used with administration of blood products 6) Head injury patients….being slightly hypertonic

38. NS Osmolarity ~ 308 Slightly hypertonic

39. Contraindications of NS HTN Patients with edema/ fluid overload states (CHF)

40. Disadvantage Metabolic acidosis – due to high chloride concentration ( Hyperchloremic acidosis)

41. RL Most physiological fluid Sodium lactate is metabolized in liver to bicarbonate. Corrects metabolic acidosis

42. Indications : RL Hypovolaemia Metabolic acidosis

43. Contraindications: RL Liver diseases Along with Blood transfusion….??? Ca +2 in RL – binds with citrate (anticoagulant)….promotes clots in donor blood….. Not to administer in in one i.v line