Intraoperative fluids

iv fluids in intraoperative fluids management

1. I.V. Fluids & Intraoperative Fluid Management Presentation at Department of Anesthesia Dr. Bishal Sapkota Resident MDGP &EM IV Batch, PAHS

2. Percentage of water in human body Fetus - 100% Less – fat / lean body mass, female, old More – infants, muscular body

3. Body Fluid Compartments (Based on Average 70-kg Male) Compartment Fluid as Percent Body Weight (%) Total Body Water (%) Fluid Volume (L) Intracellular 40 67 28 Extracellular Interstitial 15 25 10.5 Intravascular 5 8 3.5 Total 60 100 42

4. Fluid Compartments Total Body Water (TBW) Intracellular fluid Extracellular fluid 2/3 of TBW 1/3 of TBW - Interstitial fluid 4/5 - Plasma 1/5

5. Balance Concept If the quantity of a substance is to remain stable within the body, its input by means of ingestion or metabolic production must be balanced by means of excretion or metabolic consumption. Total body input = output Stable balance Gain via input > loss via output positive balance Loss via output > gain via input negative balance

6. Body fluid movement Diffusion : process by which dissolved substances cross semi-permeable membranes leading to equal conc. on both sides Simple Fascilatated (diffusion with the help of carriers) Osmosis : process of transfer of water across a semi-permeable membrane when equilibrium cannot be achieved by just diffusion of solute molecules (when they are too large to pass through pores)- this force is osmotic pressure.

7. Filtration: H 2 O and dissolved substances move from an area of greater hydrostatic pressure to an area of lesser hydrostatic pressure Active transport: Transport with the help of activated pumps like Na+-K+ pump.

8. Regulation of Fluid in Human Body ECF – acts as intermediary between the cells and external environment All exchanges of H 2 O and other constituents between ICF and external world must occur through ECF Plasma is the only fluid that can be acted upon to control the volume and composition. ICF in turn is influenced by changes in the ECF

9. Factors regulated to maintain fluid balance ECF volume- this must be closely regulated to help maintain blood pressure. Maintenance of salt balance is important in long term regulation of ECF volume. ECF osmolarity - this must be regulated to prevent swelling and shrinkage of the cells. Maintenance of water balance is important in its long term regulation .

10. Relation between ECF and ICF Osmolarity of ECF is maintained by Na + and its attendent anions whereas K + and its accompanying anions are responsible for ICF osmotic activity Na + - K + pump plays an important role for maintaining homeostasis Any condition leading to loss or gain of free H 2 O leads to changes in ECF osmolarity

11. Plasma Osmolality This can be calculated using the concentrations of sodium, chloride, glucose and urea in plasma Plasma osmolality( mOsm /kg H 2 O) = (2x Plasma Na + ) + Glucose/18 + BUN/2.8 ** Normal adult value is 285mOsm/kgH 2 O

12. It is thus crucial that ECF osmolarity be maintained within very narrow range to prevent cell from : Swelling - osmotically gaining H 2 O from ECF Shrinking - osmotically losing H 2 O to ECF

13. ECF Hypertonicity Excessive concentration of ECF solutes is usually associated with DEHYDRATION (negative free water balance) Causes: -Insufficient H 2 O intake ( eg . desert travel ) -excessive H 2 O loss ( sweating, vomiting ) -Diabetes Insipidus ( deficiency of ADH )

14. What is ECF Hypertonicity ? H 2 O moves out of cells (ICF) to reach more concentrated ECF till equilibrium occurs cell shrinks as H 2 O leaves them shrinkage of brain neurons Confusion, delirium, convulsions, coma + Circulatory problems - hypotension, death

15. ECF Hypotonicity Hypotonicity of ECF is associated with OVERHYDRATION (positive free water balance) Causes: - Renal failure - SIADH (excess water retained in body due to absence of ADH) - Excessive intake of water by normal people

16. ECF Hypotoniocity (Dilution of ECF compartment) Movement of water from more dilute ECF to more concentrated ICF(i.e. CELLS) Pronounced swelling of brain cells Confusion, irritability, dizziness, vomiting, convulsion, coma, death Nonneural symptoms : swelling of muscle cells, circulatory disturbances like HTN, edema (due to expansion of plasma volume)

17. IV Fluids. Chemical structure - Crystalloids Colloids Indication - Maintenance fluid Replacement fluid Osmolarity – Iso - osmotic / Isotonic Hyper osmotic / Hypertonic Hypo osmotic / Hypotonic

18. Define Crystalloids and Colloids. Crystalloids :- Fluids comprised of water and electrolytes or simple crystal compound only e.g . dextrose , NS, RL, Isolyte -P, hypertonic saline etc. Colloids :- Fluids having substances of high molecular weight like proteins starch or gelatin efficient to produce oncotic pressure e.g . albumin, Gelatins ( haemaccel ) , dextran, HES

19. Normal saline solution Bottle containing 500 ml solution of sodium chloride in the strength of 0.9 % w/v. Each 100 ml contains- NaCl 0.9 gm ( 900mg) Na + / Cl- 154 mEq /L Osmolarity : 308 m Osmol /L pH : 4.5 – 5.6

20. Uses of NS : As a replacement fluid. To treat hyponatraemia . To dilute / dissolve the drugs. As a irrigating fluid. To toilet the body cavity. Side effects - when infused in excess. hyperchloremic metabolic Acidocis overhydration : CHF, pulmonary oedema ….

21. Ringer Lactate Solution/ Hartman Solution Bottle containing 500ml solution of Ringer Lactate. Contains – Na + - 131 mEq /L K+ - 5 mEq /L Ca++ - 4 mEq /L Cl- - 111mEq/L lactate- 29 mEq /L pH : 6. 5 Osmolarity 280 mOsmol /L (slightly hypotonic )

22. RL Uses - replacement solution of choice Intraoperative , hypovolemic shock, burn, trauma etc. Contra indications hepatic failure Lactic Acidosis

23. Dextrose solution 5%. Bottle containing 500ml sol of dextrose in the strength of 5% w/v. Each 100 ml contains : Dextrose - 5 gm Calorie . - 20 kcal maintenance, Isotonic-  becomes hypotonic in body as glucose is quickly metabolized leaving only water Osmolarity : 278mOsmol / L PH : 4

24. Dextrose solution 10% Bottle containing 500 ml dextrose solution in the strength of 10%w/v . Each 100ml contains Dextrose 10 gm Calorie 40 kcal. Type of fluid- Crystalloid, maintenance, Hypertonic Osmolarity - 556 mOsmol /L PH : 4.5

25. Dextrose Normal Saline : ( DNS) Bottle containing 500ml solution of dextrose and saline in the strength of 5% and 0.9% w/v respectively. Each 100 ml contain - Dextrose 5 gm / Sod . Chloride 0.9gm(900mg ) Na +/Cl- 154 mEq /L Cal 20 kcal/ 100ml Crystalloid , maintenance/ replacement, hypertonic . Osmolarity 586 mOsmol /L pH : 4.5

26. Uses Of Dextrose Solution To keep the IV line open. To treat and avoid hypoglycaemia - DM. As a component of GKI. As a component of TPN. When sodium is contraindicated (and IV fluid is required) e.g. CHF, renal failure pulmonary oedema

27. Colloids Types — 1. Natural (albumin). 2. Synthetic / artificial Dextran, gelatin.

28. Dextran Poly saccharide (glucose polymer). Synthesized by fermentation of sucrose. Dose –25 ml/kg/day. Intravascular stay period . Dextran 40(10 %) 2-4 hrs. Dextran 70 (6%) 6hrs …

29. Dextran Indicate their average molecular weight. 40 40,000 D. 70 70,000 D Bottle containing 500 ml solution of dextran 40 in the strength of 10 % w/v in NS. Each 100 ml contains- Dextran 40 ---10 gm/ Sod chloride --0.9 gm

30. Side effects- Anaphylactic / anaphylactoid reaction. Interfere in blood coagulation & cross matching. Increases the bleeding time. Decreases the platelets adhesiveness. ARDS (rarely) Dextran 40, 70

31. Gelatin solution ( Haemaccel ) Bottle containing 500ml solution of degraded gelatin in the strength of 3.5% w/v and electrolytes. Each 100 ml contains – Polypeptide of degra.gelatin --- 3.5gm

32. Gelatin Electrolytes : Na+/ Cl- 145 mEq /L , K+ 5.1 mEq /L , Ca++ 12.5 mEq /L osmotic pressure --- 300mOsmol/L Average molecular weight -- 30,000 D Intravascular stay time ---2 – 3 hr Dose- 20 ml / kg / day (1000 ml-50 kg)

33. Gelatin solution ( Haemaccel ) Indications / uses As plasma expander, hypovolaemic shock, burns, trauma, peri -operatively to replace the blood loss. As preloading fluid in spinal anesthesia. Side effects Anaphylactic / allergic reactions.(0.146%). ( source - animal bones). Over hydration -> pulmonary oedema,CHF . Short stay in vascular comp. (2-3hr). May interfere in coagulation. (high dose)

34. Hydroxy -ethyl starch(HES) Bottle containing 500 ml solution of HES-200 in the concn of 10 % w/v.in NS. Each 100 ml contains: HES - 10gm. NACl - 0.9 %. Na + /Cl- 154mEq/L Source --- Maize Type- colloid, replacement, isotonic.

35. Hydroxy ethyl starch(HES) dose IV stay period HES 200 10% 20ml/kg/day 4-8hr HES 450 6% 20ml/kg/day 6-8hr Side effects Anaphylactic reaction, skin rashes, bronchospasm, thrombocytopenia, bleeding disorder. (low incidence ).

36. Human albumin Bottle containing 50 ml solution of human albumin 25% w/v. Sterile, tested to be free of hepatitis and HIV Antibodies.IV single infusion. Each 100 ml contains- Human albumin - 25 gm Type- natural colloid, replacement, isotonic. Preparations 5%, 20%, & 25%.

37. Human albumin Indications/uses Plasma expender used to restore / maintain blood volume. Sepsis, burn, trauma, shock. Hypoproteinaemia – dietary, renal, pregnancy. Side effects: Anaphylactic reactions Disease transmission

38. Summary of colloids G elatin D extran HES A lbumin Chemistry Degradation product gel polysaccharides starch protein Source animal bone sucrose maize human blood Concentration 3.5% 10, 6 % 3,6,10% 5,20,25% IV stay 2-3 hrs ( 2-4hrs) even 6 hrs 2,4,8hrs 2 – 4 – 8 hrs

39. Intra-operative Fluid Requirement Maintenance – normal requirement of fluid . By 4-2-1 rule

40. Intra-operative Fluid Requirement B. Fasting fluid deficit = hrs of NPO × maintenance fluid

41. Intra-operative Fluid Requirement C. Third space fluid loss/ hr intraoperative fluid require = A+B+C + urineoutput + blood loss

42. Blood transfusion Estimated Blood Volume( EBV):

43. Increasingly, transfusions are not recommended until the hematocrit decreases to 24% or lower ( hemoglobin <8.0 g/ dL ), but it is necessary to take into account the potential for further blood loss, rate of blood loss, and comorbid conditions ( eg , cardiac disease). Intraoperative blood transfusion is done: preoperative deficit ( eg . anaemic ) Blood loss ≥ ABL

44. Refrences Miller’s Anesthesia 8 th Edition Guyton And Hall Textbook Of Physiology 13 th Edition Morgan & Mikhali’s 6 th Edition Essential Clinical Anesthesia “ Cambridge University ” 2011 Short Textbook Of Anesthesia 6 th Edition “Practical Guidelines On Fluid Therapy ” By Sanjaya Pandya 2 nd Edition