PERI OPERATIVE FLUID THERAPY IN PATIENT

Fluid therapy in a concise manner.

1. PERIOPERATIVE FLUID THERAPY SPEAKER-DR.RUPESH KUMAR SINGH MODERATOR –DR.TIRTHASISH MANDAL

2. Outline : Physiology of water balance. Classification of IV fluids. Crystalloids. Colloids Crystalloids vs colloids. Perioperative Fluid therapy

3. Distribution of body fluid The total body fluid is distributed mainly between two compartments: The extracellular fluid. The intracellular fluid. The extracellular fluid is divided into The interstitial fluid. The plasma . Transcellular fluid.

4. Insensible fluid input= 300ml – Oxidation Insensible fluid loss= 1000ml Skin – 500ml Lungs – 400ml Stool – 100ml Normal daily insensible fluid loss = 700ml. Daily fluid requirement = urine output + 700ml. NORMAL W A T E R BALANCE

5. Daily fluid requirement : Hol l iday Segar Estimate 4 mL / kg / hour for the first 10kg of body mass. 2 mL / kg / hour for the second 10kg of body mass (11kg - 20kg) 1 mL / kg / hour for any kilogram of body mass above 20kg (> 20kg) Therefore a 70kg adult will require 40+20+50=110ml/hr maintenance fluid

6. NORMAL FLUID AND ELECTROLYTE REQUIREMENT 1. WATER REQUIREMENT: Rough calculations. Measurable loss (intestine + kidney) + 700ml. 20- 40ml/kg/day. C. 1000- 1500ml/m2/day. D. First 10 kg: Second 10 kg: For rest weight: 4ml/kg/hr. 2ml/kg/hr. 1ml/kg/hr. Sodium- 100(60-150) mEq/day or 6gm of NaCl/day. Potassium- 40-60mEq/day (20mEq= 1.5gm KCl) daily urinary loss of potassium is about 20mEq/day. Glucose- 100 gms of dextrose. Provides calories to the body, prevent breakdown and catabolism of endogenous protein, prevent depletion of liver glycogen and prevent ketone acids .

7. Daily Electrolyte Requirements :

8. C L A SS IFI C A T IO N OF IV FLUIDS : 1. Maintenance fluids – hypotonic solutions (To maintain patient’s hydration & electrolyte intake that balance daily obligatory loss. ) Dextrose Dextrose with 0.45%Nacl 2. Replacement fluids – ( Correction of ongoing and additional losses that occur during the course of therapy. ) Isotonic saline DNS RL Isolyte M, P and G Resuscitation - For correction of shock with the achievement of an adequate perfusion pressure.

9. CRYSTALLOIDS Crystalloids are aqueous solutions of inorganic and small organic molecules, the main solute being either sodium chloride or glucose . Depending on the concentration of the solute, manufactured crystalloid solutions are – Isotonic, Hypotonic, Hypertonic. Hypotonic Isotonic 5% dextrose ,D5 1/2 NS OR 1/4NS. 0.9%Nacl, ringer lactate, ringer acetate. Hypertonic - 3%,5%, 7.5% NaCl. Crystalloids :

10. TONICITY ISOTONIC HYPOTONIC HYPERTONIC Osmolality of 275- 295 mOsm/kg Osmolality of <270 mOsm/kg Osmolality of >300 mOsm/kg No shifting of fluid Shifting of fluid from intravascular to intracellular space and interstitial space Water moves out of intracellular space to extracellular space Increases ECF Hydrates the cell causing cellular swelling Dehydrates the cell causing shrinkage Osmolality of body water is 285 to 290 mosm /kg and is same in ECF and ICF due to free water movements between the compartments.

11. Comparison of plasma and crystalloid fluids :

12. 0.9% SODIUM CHLORIDE Also called Normal saline which is an inappropriate term as its pH is lower than plasma (5.7 vs 7.4) osmolality higher than plasma (308 vs 290mOs/L) and has higher concentration of Na (154 vs 140mEq/L) & Cl (154 vs 13mEq/L) than plasma….. Not physiologically normal. Composition: One litre fluid contains: 9gm NaCl (0.9%= 0.9gm in 100ml) Sodium- 154mEq, Chloride 154mEq [1 normal NaCl mean (molecular wt of NaCl 23+35=58, 58 gm in1L)…….. Not chemically normal.]

13. INDICATIONS: Hypovolemic shock. Water and salt depletion. Alkalosis with dehydration. Initial fluid therapy in DKA. Hypercalcemia. Fluid challenge in prerenal ARF. Irrigation for washing of body fluids. As a vehicle for drugs

14. Disadvantages of No r mal saline : Interstitial edema- because increase Na content increases the tonicity of interstitial fluid and promote Na retention by suppressing RAAS. Metabolic acidosis - @30ml/kg/hr (large volume isotonic saline resuscitation) has shown to decrease the pH and cause metabolic acidosis i.e; hyperchloremic acidosis due to high concentration of chlo r ide in 0.9% NaCl Decrease in renal perfusion has been observed presumably from chloride mediated renal vasoconstriction.

15. RINGER’S LACTATE(RL ) COMPOSITION: One litre of fluid supplies: k= 4, ca = 3, Na = 130, cl= 109, HCO3=28 PHARMACOLOGICAL BASIS: It is most physiological fluid. Rapidly expands intravascular volume because of high Na (130) – effective in hypovolemia Sodium lactate in RL is metabolized in liver to bicarbonate - useful in correction of metabolic acidosis .

16. Indications : Diarrhea induced hypovolemia with hypokalemic metabolic acidosis. For replacing fluid in postoperative patients, burns, fractures. DKA For maintaining normal ECF fluid and electrolyte balance during and after surgery. Contraindications and Precautions : In liver disease ,severe hypoxia and shock – causes lactic acidosis Severe metabolic acidosis where conversion from lactate to bicarbonate is impaired. In vomiting or continuous nasogastric aspiration. Along with blood transfusion.

17. I ND I C A T IO N S : For pre and postoperative fluid replacement . For treatment or prevention of ketosis in starvation, diarrhoea, vomiting and high grade fever. Hypernatremia. Can be used for prevention and treatment of dehydration due to inadequate water intake or excessive water loss . Adequate glucose infusion protect the liver against toxic substances. 5% DEXTROSE P rotein-sparing effect: Dextrose provides 3.4 kilocalories ( kcal) per gram when fully metabolized, so a 5% dextrose solution (50 grams dextrose per liter) provides 170 kcal per liter. Infusion of 3 liters of a D5 solution daily provides 3 x 170 = 510 kcal/day, which is enough nonprotein calories to limit the breakdown of endogenous proteins.

18. C ontraindications : Cerebral edema (hypotonic in nature ) Neurosurgical procedures (increase ICP ) Acute ischaemic stroke Hypovolemic shock (Hyperglycemia induced osmotic diuresis ) Hyponatremia. Uncontrolled diabetes and severe hyperglycemia Precautions: I.V 5%D may cause local pain, vein irritation, and thrombophlebitis. Rate of administration 0.5 gms/kg body wt/hour can be safely given without causing glycosuria. Equivalent to – “666ml/hour of 5%dextrose and 333ml of 10%dextrose”

19. Dextrose with half strength saline (5%D +0.45%Nacl ) COMPOSITION: One litre of fluid contains: Sodium - 77meq Chloride – 77meq Glucose - 50g m Indications: Fluid therapy in paediatrics Early postoperative period As maintenance fluid therapy Contraindications: Hyponatremia Severe dehydration due to diarrhoea and vomiting – need for large salt replacement

20. Indications: Correction of salt depletion and hypovolemia with supply of energy. Correction of vomiting or nasogastric aspiration induced alkalosis and hypochloremia along with supply of calories. Fluid compatible with blood transfusion. Contraindications: Severe hypovolemic shock . DNS (5%D +0.9%NACL) COMPOSITION: One litre of fluid contains: Glucose - 50gm, Sodium - 154meq Cl - 154meq

21. It provides all electrolytes lost by gastric juice, corrects alkalosis and provides calories. Ammonium ions are converted into urea and hydrogen ions in liver. “It is the only available fluid which directly corrects metabolic alkalosis.” ISOLYTE- G Indications: In vomiting and continuous gastric aspiration Metabolic alkalosis . Contraindications : Hepatic failure Renal failure Metabolic acidosis Severe vomiting with shock

22. ISOLYTE P It provide electrolytes, maintain pH, supplies calories and replaces water deficit. As compared to adult, children need more water and same electrolytes. So, Isolyte P provides almost double water but same electrolytes as Isolyte M. INDICATIONS: Chiefly used as maintenance fluid in infants and children. Excessive water loss or inability to concentrate urine( i.e diabetes insipidus ). CONTRAINDICATIONS: Hyponatremia (least concentration of sodium 20mEq/L). Renal failure (high concentration of potassium 20mEq/L). Hypovolemic shock(low Na, high k+, can cause hyperglycemia and osmotic diuresis).

23. ISOLYTE- M It is the richest source of potassium(35 meq /l ) Ideal fluid for maintenance fluid therapy . Indications Parenteral fluid therapy – ideal maintenance fluid. Hypokalemia secondary to diarrhoea, vomiting. Contraindications Renal failure . Hyponatremia and water intoxication . Adrenocortical insufficiency . Burns.

24. ISOLYTE - E Extracellular replacement solution. Similar to ECF except that it has double the concentration of potassium and acetate. Only IV fluid that corrects magnesium deficiency . Indications: Diarrhoea Metabolic acidosis Maintenance of ECF volume preoperatively. Contraindications: Metabolic alkalosis Vomiting/nasogastric aspiration

25. DEXTRO SE (GM/L) Na K Cl ACETATE LACTATE NH4 Cl Ca 5% DEXTROSE 50 0.9% SALINE 154 154 D – 5%, 0.45%SALINE 50 77 77 DNS 50 154 154 RL 130 4 109 28 3 ISOLYTE – G 50 63 17 150 70 ISOLYTE – M 50 40 35 40 20 ISOLYTE - E 50 140 10 103 47 5

26. Characteristics of IV fluids Most physiological iv fluid - Ringer’s lactate Because its constitution is similar to ECF Fluid that does not contain glucose – Isotonic saline and RL Preferred in diabetic patients Fluids that does not contain potassium Isotonic saline, DNS and dextrose solutions . Preferred in renal failure and hyperkalemia. Fluids to be avoided in renal failure Isolyte – M, P, G and E RL

27. IV fluids that does not contain sodium and chloride 5%, 10% and 20% dextrose solutions. IV fluids that can correct acidosis Isolyte – M, P and E Ringer’s lactate - Acetate gets converted to bicarbonate - lactate gets converted to bicarbonate. IV fluid that can correct alkalosis Isolyte – G - Ammonium chloride gets converted to H+ and urea Fluids avoided in Liver failure RL – impaired conversion of lactate to bicarbonate . Isolyte – G - Impaired conversion of ammonium chloride to H+ and urea.

28. . Assessment Assess whether the patient is hypovolaemic. Assess the patient's likely fluid and electrolyte needs from history, clinical examination, medications, Clinical monitoring and laboratory investigations : Hematocrit, Urinary Na, BUN NICE GUIDELINES

29. Resuscitation If patients need IV fluid resuscitation , use crystalloids that contain sodium in the range 130–154 mmol/l, with a bolus of 500 ml over less than 15 minutes . Consider human albumin solution 4–5% for fluid resuscitation only in patients with severe sepsis.

30. Routine maintenance If patients need IV fluids for routine maintenance alone, restrict the initial prescription to: 25–30 ml/kg/day of water and Approximately 1 mmol/kg/day of sodium and chloride and Approximately 50–100 g/day of glucose to limit starvation ketosis. Consider prescribing less fluid for patients who: Are older or frail Have renal impairment or cardiac failure Are malnourished. Consider delivering IV fluids for routine maintenance during daytime hours to promote sleep and wellbeing.

31. Replacement and redistribution Adjust the IV prescription to account for existing fluid and/or electrolyte deficits or excesses , ongoing losses or abnormal distribution. Seek expert help if patients have a complex fluid and/or electrolyte redistribution issue or imbalance, or significant comorbidity,

32. Training and education Hospitals should establish systems to ensure that all healthcare professionals involved in prescribing and delivering IV fluid therapy are trained on the principles of fluid therapy. should receive training and be competent in, recognising, assessing and preventing consequences of mismanaged IV fluid therapy.

33. COLLOIDS Colloids - are homogeneous non- crystalline substances containing large molecules. Have much greater capacity to remain within the intravascular space. These solutions restore the plasma volume more efficiently and act as volume expanders. Colloids: Hydroxyethyl starches. Gelatins. Dextran. Albumin.

34. COLLOIDS TYPE OF FLUID EFFECTIVE PLASMA VOLUME EXPANSION PER 100ML INFUSION DURATION OF EXPANSION 5% ALBUMIN 70- 130 ML 16HRS 25% ALBUMIN 400- 500 16 6% HETASTARCH 100- 130 24 10% PENTASTARCH 150 8 10% DEXTRAN- 40 100- 150 6 6% DEXTRAN- 70 80 12

35. ALBUMIN Physiological plasma protein Chief function of albumin is to maintain plasma oncotic pressure . It also helps in binding and transport of low molecular substances like bilirubin . Commercially available as 5% solution and 25% solution . Also called salt poor albumin 5% albumin colloid osmotic pressure - 20mm of hg expands the plasma volume to roughly the same as volume infused . 25% albumin colloid osmotic pressure - 70mm of hg expands the plasma volume by 4 to 5 times volume infused . This plasma volume expansion occurs at the expense of interstitial fluid volume.

36. Indications Plasma volume expansion - Acute hypovolemic shock ,burns and severe albumin loss. Hypoproteinemia – in liver disease, malnutrition As an exchange fluid in therapeutic plasmapheresis to replace removed plasma. Adverse effects: Nausea , vomiting febrile reaction and allergic reaction including anaphylactic shock. Precautions and contraindications : Fast infusion may cause volume overload and pulmonary edema. Severe anemia, cardiac failure .

37. DEXTRAN Dextrans are glucose polymers produced by bacteria (leuconostoc) incubated in sucrose medium . Dextran 70 and dextran 40 . Both expands intra vascular volume not substitute for whole blood and for plasma protein. Improves microcirculation . Prevents intravascular aggregation of RBC’s. So, help in prevention of thromboembolism. Dextrans produce a dose-related bleeding tendency that involves impaired platelet aggregation, decreased levels of Factor VIII and von Willebrand factor, and enhanced fibrinolysis.

38. Indications : Correction of hypovolemia – for short time rapid expansion of plasma volume. Prophylaxis of DVT and post operative and post traumatic thromboembolism. To improve blood flow and microcirculation in threatened vascular gangrene. Contraindications: Severe oligo- anuria and renal failure. Severe CHF or circulatory overload. Hypersensitivity to dextran. Precautions Interferes with blood grouping and cross matching

39. HAEMACCEL It is a sterile , pyrogen free , colloidal plasma volume substitute which contains a polymer of degraded gelatin with electrolytes. Composition: Each litre contains : polymer from degraded gelatin 35 gm Na - 145meq cl - 145, ca - 12.5, k - 5.1

40. Indications : Rapid expansion of intravascular volume - Shock , burns , trauma and intra or post operative blood loss. Prophylactic use in major surgery to reduce total volume of fluid replacement. Advantage Does not interfere with coagulation, blood grouping and cross matching Side effects: Hypersensitivity reaction. Bronchospasm and fall in BP.

41. HYDROXYETHYL STARCH (HES) : HES preparations are classified by the ratio of hydroxyl radical substitutions per glucose polymer (OH/glucose ),which is called the molar substitution ratio and ranges from zero to one. Since hydroxyl radicals resist enzymatic degradation, higher OH/glucose ratios are associated with prolonged activity. Higher molar substitution ratios increase the risk of coagulopathy. HES can impair hemostasis by inhibition of Factor VII and von Willebrand factor , and impaired platelet adhesiveness. Clinically significant coagulopathies are uncommon unless large volumes of HES are infused. Indications: Hypovolemic shock Contraindications: CHF or impaired renal function

42. Advantage Non antigenic. Does not interfere with blood grouping and cross matching. Less expensive than albumin. Expands plasma volume for a longer period. Disadvantage Increases serum amylase and remains elevated for 3- 5 days after use.

43. CRYSTALLOID VS . COLLOID

44. Monitoring fluid therapy : Parameters which suggest correction of hypovolemia and adequate fluid replacement: Weight Skin and tongue Sensorium Urine output Pulse rate Blood pressure Haematocrit Bun and creatinine Urinary Na Metabolic acidosis CVP or PAWP

45. CVP monitoring Central venous pressure is the pressure of blood measured in the venacava at its junction with right atrium. Close CVP monitoring permits rapid correction of fluid deficit with large volume of iv fluid while protecting against risk of volume overload. Indicated for proper and safe fluid infusion in patients with shock, cardiac or critically ill patients in ICU and during major surgery. CVP measured by placing a specialized catheter near the right atrium in SVC through the peripheral veins and connecting it with water filled manometer. Level of water in the transparent tube attached to measuring scale reflects CVP. Normal value : 6 – 10 cm of water

46. LOW CVP: True hypovolemia - blood loss and dehydration. Relative hypovolemia - caused by peripheral vasodilatation as in spinal anesthesia , septicemia and anaphylactic shock. HIGH CVP: Volume overload. Cardiac causes - CCF, cardiac tamponade , constriction pericarditis and TR. Pulmonary causes - embolism, tension pneumothorax , COPD ,Cor pulmonale and IPPV .

47. Perioperative fluid therapy: The goals of fluid therapy for major surgery are as follows: To ensure adequate circulating volume to support cellular O2 delivery and avoid the deleterious effects of hypoperfusion on cellular function and survival, inflammation and neurohumoral responses. 2. To avoid the iatrogenic side effects of fluid administration; excessive intravascular volume, edema, excess Na+ or Cl − load, toxicities related to synthetic compounds. IV fluid quantities may be given in two main ways: (1) by estimating the requirements based on patient weight, the phase of surgery, and nature of losses to estimate the required dose . ( 2) by direct measurement of an individual’s physiologic variables and administering fluid in sufficient quantities to achieve an improvement in these physiologic variables, so-called goal-directed therapy .

48. Intraoperative fluid calculation : Maintainence fluid(calculated from 4- 2-1 formula)+fasting deficit( maintainence fluid ×hours of fasting, 50% given in 1 st hour, 25%given in 2 nd hour, 25% given in 3 rd hour)+3 rd space loss+ compensatory intravascular expansion to effect of anaesthesia of decreasing cardiac output)+ongoing losses. Losses calculated from: 1.Surgical suction container 2.Surgical sponges(4 by 4) hold 10 ml blood 3.Soaked laparotomy pads holds 100-150 ml compensatory intravascular expansion: Fluid must be given to expand the load volume to compensate for venodilation . Expansion with 5-7 ml/kg of balanced salt solution must occur before or simultaneous with the onset of anaesthesia .

49. GOAL DIRECTED THERAPY: Goal-improved tissue perfusion and clinical outcome Based on measuring key physiologic variables Cardiac output or Global O₂ delivery Achieved with 1.administering fluids, and 2.possibly inotropes, vasopressors, vasodilators, and 3.RBCs Targets are defined physiologic endpoints and not dependant on objective assessments of fluid status. GDT means giving fluid by measuring dynamic cardiac functions: 1.Flow time through aorta(target should be >400ms) 2.SV and pulse pressure variation(>10-15% confirm hypovolemia ) 3.Cardiac output

50. TECHNIQUES USED FOR PERIOPERATIVE GDT: Pulmonary artery catheter (PAC ): 1.Gold standard hemodynamic monitor, 2.provides measured and derived values for Left and right heart filling pressures, mixed and central venous saturations and CO. Esophageal Doppler monitor (EDM ): ultrasound measurement of descending aorta blood velocity=> SV => CO Echocardiography CVP Lithium dilution [lithium dilution cardiac output ( LiDCO )] Arterial blood pressure and waveform analysis. Lactate. Thoracic Bioimpedance (non-invasively measures SV & CO through 4 surface ECG electrodes ).

51. TYPICAL PRACTICAL APPROACH Preoperative Emergency surgery Acute disturbances of fluid compartments. Timely resuscitation guided by rational physiologic endpoints: 1.Blood pressure and heart rate 2.Lactate 3.urine output, and 4.mixed or central venous O₂ saturations . Upper GI losses quantified and replaced with isotonic saline . Lower GI losses with balanced crystalloid . K+ should be supplemented as appropriate. Oral clear fluid intake until 2 hours preop . Bowel prep in selected cases only and an infusion of 1 to 2 L of balanced crystalloid with K+ supplementation for adequate hydration in such cases . Chronic comorbidities assessment for influence on fluid and electrolyte balance.

52. Intra-operative:   Balanced crystalloid used to replace the ongoing water and electrolyte losses. Hypotension by anesthesia is related to vasodilation and reduced inotropy , if needed vasopressors can be used. Fluid therapy in high risk patients guided by 1.invasive CVP monitoring for early recognition of overt hypovolemia and 2.markers of global tissue perfusion, like lactate and acid-base status . In certain orthopedic and intraabdominal operations CO optimized by titrating boluses of a suitable colloid. Blood loss replaced with colloid or blood and blood products depending on the volume lost. Crystalloid used as an alternative for intravascular plasma volume expansion. Overall the goal is to achieve euvolemia by the end of surgery or the early postop period.

53. Post-operative: Assessment of fluid status made based on 1.clinical examination and 2.lactate , 3.central or mixed venous saturations, and 4.cardiac output variables. If euvolemic then early oral intake is well tolerated and safe In patients requiring ongoing IV therapy in postop phase: 1. Monitor for hyponatremia and other electrolyte derangements. 2. Fluid requirements should be strictly divided into three categories :

54. A. " Pure" maintenance requirements ( salt poor , modest volume of free water to account for the postoperative state of salt and water retention ) •  1500  to  2500  mL or 1 to  1.2 ml/kg/ hr of fluid with 50 to  100   mEq Na+ & 40 to 80 mEq K+ should be given in first 24 hours B . Replacement of ongoing losses Assessment of IV volume status and adequacy of organ perfusion. Losses from the GI tract replaced with isotonic saline or balanced crystalloid with K+. Losses to third spaces with a mixture of colloid and crystalloid Blood loss replaced with colloid, blood, or blood products, and definitive intervention. C . New requirements ( resuscitation) Postop complications; hemorrhage (absolute hypovolemia ) or acute sepsis (relative or absolute hypovolaemia ). Postop oliguria, particularly in the first postop 24 hours . Large volumes of fluid challenge are inappropriate and may aggravate postop positive fluid and Na+ balance.

55. PAEDIATRICS Proposed strategies: Using half to two thirds of calculated  4-2-1 formula maintenance fluids , Avoiding the hypotonic fluids (4% dextrose with  0.18 % NaCl ) Returning to oral fluids as early as possible Ensuring euvolemia to minimize the ADH response Not confusing maintenance requirements with ongoing losses (e.g., Gl or blood ), which should be replaced by isotonic crystalloids, colloids, or blood. Checking electrolytes at least daily in those still receiving IV fluids . Isotonic saline "safer" for postop maintenance, but risk of Na+ overload and hyperchloremic acidosis.

56. BURNS: IV fluid therapy is generally instituted for burns of greater than 15% total body surface area in adults and 10% total body surface area in children Parkland Burn Fluid Resuscitation Formula First 8 hours: 2 mL/kg x % TBSA (lactated Ringer solution) Next 16 hours: 2 mL/kg x %TBSA (lactated Ringer solution) Next 24 hours:  0.8  ml/kg x %TBSA (5% dextrose) +  0.015  mL/kg x %TBSA (5% albumin) Down-titration of fluid volumes if UO is adequate (0.5 to 1 mL/kg/ hr ) Excessive fluid administration ("fluid creep") may cause: Pulmonary edema Fasciotomies in nonburned muscle compartments Raised IOP Conversion of superficial to deep burns Intraabdominal hypertension and compartment syndrome

57. UPPER GASTROINTESTINAL LOSS Hypovolemic hypokalemic hypochloremic metabolic alkalosis. Progressive dehydration => Increased aldosterone secretion => Na+ is retained at the expense of K+ and H+ ions, (hypokalemia, and metabolic alkalosis with a paradoxically aciduria ) Correction => Gradual rehydration with isotonic saline and K+ supplementation and changing to dextrose- containing saline depending on electrolyte analysis.

58. KIDNEY DISEASE: Preoperative assessment should focus on the adequacy of chronic dialysis in attaining euvolemia , and estimating the normal volume of native urine output. Comorbidities should be assessed and optimized. Surgery undertaken in a facility where preop and postop dialysis or hemofiltration done. In elective surgery, preoperative dialysis timed such that the patient enters the intraop phase with a normal blood volume. Fluid must be guided by cardiac monitoring. Crystalloid without potassium is preferred. Normal saline can cause hyperchloremic acidosis and can cause hyperkalemia.

59. HEART FAILURE: Goals => Preserve CO, preload, contractility, and afterload. Ventricles poorly compliant and require adequate preload and adequate diastolic filling time. Excessive volume infusion and preload => Impaired contractility and worsening CO Invasive monitoring with either EDM/ PAC for fluid therapy Restrictive Fluid therapy or GDT is preferred. Striking a balance between hypovolemia and hypervolemia is particularly important in patients with heart failure.

60. HEPATIC FAILURE: Progressive liver disease and cirrhosis cause 1.peripheral vasodilation and 2.relative intravascular depletion (total body Na+ and water are retained with ascites and edema) Aim is reduction of total body salt and water [dietary fluid and salt restriction, diuretics (spironolactone and loop diuretics ), and intermittent or continuous drainage of ascites] Excessive isotonic saline => salt and water overload=> further ascites and edema formation. Approach => Assess volume status and replace losses with appropriate volumes of isotonic crystalloid, colloid, or blood but avoid salt and water overload.

61. GERIATRIC: Decrease in TBW, GFR, urinary concentrating ability, aldosterone, thirst mechanism, free-water clearance . Increase in antidiuretic hormone (ADH), atrial natriuretic peptide (ANP) Renal capacity to conserve sodium is decreased. Tendency to lose sodium in the setting of inadequate salt intake. Decreased thirst response => risk for dehydration and sodium depletion. Diminished ability to respond to an increased salt load => increased Na* retention during the perioperative period. Volume expansion SHOULD BE DONE CAREFULLY

62. OBSTETRICS PIH & PREECLAMPSIA A clear association between positive fluid balance and the incidence of pulmonary edema in this condition Restricted volumes of IV crystalloid (80 mL/ hr ), and fluid balance observed carefully . Oliguria not treated by administration of large volumes of fluids if kidneys normal. Blood loss replaced with an appropriate volume of crystalloid, colloid, or blood, depending on magnitude. Invasive monitoring can be used to direct fluid therapy in severe preeclampsia.

63. MAJOR INTRAABDOMINAL SURGERY Fluid losses during surgery are caused by: 1.prolonged peritoneal exposure, 2.significant blood loss, and 3.acute drainage of tumor-related ascites. Difficult to quantify, so cardiac output monitoring, CVP, arterial pressure monitoring and serial blood gas analysis is valuable. Intraoperative drainage of ascites may require large volumes to replace the ongoing loss. Consequence of fluid redistribution is electrolyte abnormalities; e.g. hypokalemia and hypomagnesemia .