Fluid management peroperatively

1. Moderator - Dr Archana
Presenter-Dr Pragya
Perioperative fluid
management

2. INTRODUCTION
• The administration of iv fluids is the core expertise for anaesthesia
providers.
• Alongside the maintenance of triad of unconsciousness, pain relief
and neuromuscular relaxation, iv fluid therapy is also the core element
of perioperative practice of anaesthesia.
• The aim here is to avoid dehydration, maintain an effective circulating
volume, and prevent inadequate tissue perfusion during a period when
patient is unable to achieve these goals through normal fluid intake.

3. BASIC PHYSIOLOGY
Total body water:
• 60% of total body weight consists
of water.
• Obese have proportionately less body water
while new born infants have almost 80% water.
• This total body water is divided into 2/3rd
ICF(40%) and 1/3rd ECF(20%)
• ECF further divided into 5% plasma and
15% interstitial fluid
2

4. FLUID LOSSES
To determine daily fluid requirement we need to know the insensible fluid input and loss:
• Insensible fluid input =300 ml water due to oxidation.
• Insensible fluid loss =500ml through skin + 400 ml through lung + 100ml through stool
• Thus, Fluid Loss - Fluid Input =1000-300ml =700ml ( NORMAL DAILY INSENSIBLE FLUID
LOSS)
• Fluid loss in sweating = 500ml through moderate sweating/ 1-1.5 l through severe sweating or
high fever/ 0.5-3.0l through exposed wound surface (burns) and body cavity ( laparotomy)
• Thus Daily Fluid Requirement =urine output+ 700ml

5. ELECTROLYTE DISTRIBUTION
ELECTROLYTE ECF ICF
Sodium 142 10
Potassium 4.3 150
Chloride 104 2
Bicarbonate 24 6
Calcium 5 0.01
Magnesium 3 40
Phosphate & Sulphate 8 150

6. ECF ICF
Major cations Sodium Potassium & Magnesium
Major anion Chloride & Bicarbonate Phosphate, Sulphate, Protein

7. FLUID THERAPY
For a proper fluid therapy it is necessary to know:
• Etiology of fluid deficit and type of electrolyte imbalance present.
• Associated illness (i.e. DM, HTN, IHD, renal or hepatic disorders etc.)
• Clinical status ( hydration, vital data, urine output etc.)
• What type, when and how much of the iv fluid should be used
• Indications and contraindications of various iv fluids

8. EVALUATION OF INTRAVASCULAR VOLUME
• PATIENT HISTORY:
• Recent oral intake
• Persistent vomiting or diarrhoea, gastric suction
• Significant blood loss or wound drainage, iv fluids and blood
administration
• Recent hemodialysis if patient has kidney failure
•

9. LABORATORY SIGNS OF DEHYDRATION
• Rising hematocrit and hemoglobin
• Progressive metabolic acidosis (including lactic acidosis)
• Urinary specific gravity greater than 1.010,urinary sodium less than 10mEq/L
• Urinary osmolality greater than 450mOsm/litre
• Hypernatremia and BUN to creatinine ratio greater than 1
0
:
1
• The hemoglobin and hematocrit are usually unchanged in patients with acute hypovolemia secondary
to acute blood loss because there is insufficient time for extra vascular fluid to shift into the intravascular
space.
• USG can reveal a nearly collapsed vena cava or incompletely filled cardiac chambers. Radio graphic
indicators of volume overload include increased pulmonary vascular and interstitial markings, diffuse
alveolar infiltrates, or both.

10. SIGNS OF HYPERVOLEMIA
• Pitting edema – presacral in bedridden patient or pretibial in the ambulatory patient
• Increased urinary flow in patients with normal cardiac, hepatic and renal function
• Late signs of hypervolemia in settings such as congestive heart failure, may include
tachycardia, tachypnea, elevated jugular pulse pressure, pulmonary crackles, wheezing,
cyanosis, pink frothy pulmonary secretions.
• CORRECTION OF FLUID OVERLOAD:
1. Diuretics
2. Fluid restriction
3. Salt restriction

11. BASIC PRINCIPLES OF FLUID THERAPY
• ADVANTAGES:
• Accurate, controlled and predictable way of administration.
• Immediate response due to direct infusion in intravascular compartment
• Prompt correction of serious fluid and electrolyte disturbances.
• DISADVANTAGES:
• More expensive, needs strict asepsis.
• Possible only in hospitalized patient under skilled supervision.
• Improper selection of type of fluid used can lead to serious problems.
• Improper volume and rate of infusion of fluid can be life threatening.
• Improper technique of administration can lead to complications.

12. • Indications:
• Conditions when oral intake is not possible e.g. coma, anaesthesia, surgery.
• Severe vomiting and diarrhoea.
• Moderate to severe dehydration and shock, where urgent and rapid fluid replacement is needed.
• Hypoglycemia where 25% dextrose is life saving.
• As a vehicle for various iv medication eg. antibiotics, chemotherapeutic agents, insulin,
vasopressor agents.
• Total parenteral nutrition.
• Treatment of critical problems: shock, anaphylaxis, severe asthma, cardiac arrest and forced
diuresis in drug overdose, poisoning, urinary stone.

13. • Contraindications:
• Intravenous fluid should be avoided if patient is able to take oral fluid.
• Preferable to avoid iv fluid in patient with congestive heart failure or volume overload.
• Complications:
• Local: Haematoma, infiltration and infusion phlebitis.
• Systemic: Circulation overload with rapid or large volume infusion especially in patients
with cardiac problems.
Rigors, air embolism and septicaemia.
• Others : Fluid contamination ,fungus in iv fluids, mixing of incompatible drugs, improper
technique of infusion, iv set or iv catheter related problems and human error related
problems.

14. PATHOPHYSIOLOGIC FLUID ALTERATIONS IN THE PERIOPERATIVE
PHASE
Preoperative
• Patients with hepatic, cardiac, renal dysfunction where sodium distribution is altered.
• Patients with end stage renal disease depend on dialysis for fluid removal and timing of
dialysis relative to surgery is critical.
• Chronic diuretic treatment may cause volume contraction in hypertensive patients making
them prone to intraoperative hypovolemia.
• Effect of preoperative fasting should also be considered.
• Bowel preparation can also cause weight loss of 1.5 to 1.7kg with high water and potassium
content.

15. Patients presenting with acute disease requiring surgical
intervention:
• Direct intravascular depletion from bleeding.
• Loss of fluid from GI tract.
• Excess gastric loss because of obstruction, vomiting, or excess nasogastric suction results in
loss of Na, K, Cl and acid.
• Loss of small bowel secretions result in high Na+, Cl- and HCO3 losses with lesser K+ losses.
• Large bowel losses such as in diarrhoea deplete large quantities of K with lesser losses of Na
and HCO3.
• Inflammation related redistribution from intravascular to extra cellular compartment.
• Fluid sequestration in physiologic third space.

16. Intraoperative
ANAESTHESIA RELATED:
• Anaesthetic agents lead to vasodilation.
• Sympathetic blockade caused by central neuraxial blockade.
• Negative inotropic effect of anaesthetic drugs.
• Blunting of auto regulatory responses within organ beds caused by anaesthesia.
• Microcirculatory dysfunction.
• Inflammatory response to surgery which leads to impaired matching of local oxygen delivery
to tissue oxygen requirements, which may not be responsive to intravascular fluid therapy.

17. • Direct loss of intravascular volume from haemorrhage.
• Insensible losses.
• Inflammation related redistribution: redistributes fluid from intravascular to extra cellular
compartment.
• Urine output during surgery.
• SURGERY RELATED:
Acute stress before and during surgery leads to activation of sympathetic stimulus
in the patients. This causes release of ACTH that stimulates adrenals to release
aldosterone and cortisol.
While aldosterone causes increased sodium and water retention and urinary
potassium loss, cortisol further increases stress. Both of these conditions aggravate
the above conditions more and more and the cycle repeats itself, finally causing low
urine output.

18. Postoperative factors
• Inflammation and immune response.
• Catabolic metabolism.
• Regulation of salt and water balance :ADH release is induced during surgery, leading to
postoperative retention of water.

19. Perioperative fluid requirements
• At each stage in perioperative journey, physician must decide how much and what type of
fluid is required.
• This is dependent on various factors like weight, comorbidity and surgical factors
like magnitude and site of surgery.
• Following factors must be taken into account:
• Compensatory intravascular volume expansion
• Maintainenece fluids
• Third space losses
• Replacement of loss

20. NORMAL MAINTENANCE REQUIREMENTS:
• For first 10 kg - 4ml/kg
• For next 10 kg - 2 ml/kg
• For rest of the weight - 1ml/ kg
• The total of above three constitutes the MAINTAINENCE FLUID
• For eg: For a 60kg person the maintenance fluid will be
4x10+2x10+1x40 = 100ml/kg

21. PRE-EXISTING DEFICITS
• Overnight fast without any fluid intake will have a pre-existing deficit.
• Deficits can be estimated by multiplying the length of fast by normal maintainence rate.
• For eg: For a 70kg person fasting for 8 hrs , the total fluid amounts to (40+20+50) ml/hr * 8hrs
of fasting =880ml.
• Now this is divided as follows : Half in 1st hour , one fourth each in next 2 hours.

22. REDISTRIBUTIVE AND EVAPORATIVE SURGICAL FLUID LOSSES :
(Third SpaceLosses)
• Classified according to degree of tissue trauma:
Degree of tissue trauma Additional fluid requirements
Minimal(eg: herniorrhaphy) 0-2 ml/kg
Moderate(eg:
open
cholecystectomy)
2-4ml/kg
Severe (eg: open bowel resection) 4-8 ml/kg

23. THIRD SPACE LOSSES
Isotonic transfer of ECF from functional body fluid compartments to non-functional body fluid
compartments.
Depends on location and duration of surgical procedure, amount of tissue trauma, ambient temperature,
room ventilation.
• SITES OF THIRD SPACING:
• Brain - Due to cardiac arrest causing cerebral edema
• Lungs : Cardiogenic/non cardiogenic pulmonary edema
• Bowel: Intrabdominal hypertension (IAP more than 12mm Hg)
• Extremities: Peripheral edema
• Third space losses constitutes of extra cellular fluid, electrolytes and small amounts of protein.

24. ETIOLOGY OF THIRD SPACE LOSS:
MEDICAL CONDITION: SURGICAL INSULTS:
- acute gastric dilatation. - following abdominal and pelvic surgeries
- acute peritonitis - following abdominal aortic aneurysmal surgery after clamp
- acute intestinal obstruction is released:
- acute pancreatitis - Declamping phenomenon
MECHANICAL INJURIES: - Fluid accumulates in ischemic area of lower limbs
- burns
- acute spreading cellulitis
- Crush injuries

25. GOAL DIRECTED THERAPY
• The practice of GDT is based on measuring key physiologic variables related to cardiac
output or global O2 delivery and administering fluids, and possibly ionotropes, vasopressors,
vasodilators and RBCs to improved tissue perfusion and clinical outcome.
• This approach to fluid administration is a continuous target process that targets defined
physiologic endpoints rather than giving fluids without objective assessments of fluid status .

26. 1. Pulmonary artery catheter -Considered as a gold standard hemodynamic monitor,providing measured and derived
values for left heart and right heart filling pressures, mixed and central venous saturations, cardiac output, DO2 and VO2
while allowing access to central circulation
2. Esophageal Doppler Monitor (EDM)
3. Arterial pressure and waveform analysis
4. Thoracic Bioimpedance
5. CVP
6. Echocardiography
7. Lactate:Areduction in elevated blood lactate concentrations is used clinically as a marker of successful
resuscitation
8. O2 extraction and venous O2 saturation (SvO2) or central venous saturation (SvO2)
VARIOUS TOOLS TO MEASURE PHYSIOLOGIC TARGETS OF GDT

27. Monitoring :
• Central venous pressure
• Mean arterial pressure
• Serum lactate
• Mixed venous oxygen saturation (MVO2)
• Cardiac output monitoring
• Vital signs and urine output (maintain more than 0.5 ml/kg/hr)
• Peripheral perfusion pressure
• Mental status for raised ICP

28. Investigation:
• Hematocrit, hemoglobin, serum electrolytes, blood urea nitrogen , serum creatinine, serum
lactate
• Intra abdominal pressure by using - Serial abdominal girth measurements and bladder
pressure measurement with Foleys catheter when urine output is less

29. FLUID RESUSCITATION:
• Isotonic saline/lactated ringers preferred for dehydration
• Boluses of colloid to increase Oncotic pressure for acute hypovolemia
• Small doses of the furosemide to prevent ARF and increase renal output
• Infuse the RBCs or whole blood
• Increase oxygen carrying capacity of blood
• Also increases intravascular oncotic pressure

30. GUIDELINES FOR FLUID REPLACEMENT IN SPECIFIC
CONDITIONS:
1. Parklands formula for BURNS:
• 4 ml x weight of person in kg x %of TBSAburned
• Gives minimum amount of fluid to be given over 24 hrs
• Half the value obtained, is given over first 8 hrs post burns
• Remaining half is given for next 16 hrs
• Resuscitation is actively downtitrated if urine output of 0.5 to 1 ml/ kg/ hr is obtained
• In addition to urine output, lactate and cardiac output can also be monitored

31. 2. HEART FAILURE:
Here we have 2 goals 1.preserve cardiac output so that we don’t have to face any “forward failure” or “backward
failure”.
2 minimize cardiac work to prevent any increase in O2 demand that further worsens the myocardial function.
Maintain a balance between hypervolemia and hypovolemia thus preventing both myocardial infarction and
tachycardia respectively.
3. RENAL FAILURE:
Preoperative assessment should specially focus on the timing of dialysis of such patients before surgery, such that the
patient enters into intraoperative phase with a normal blood volume.
Surgery in presence of hypervolemia increases risk of pulmonary and peripheral edema, hypertension, poor wound
healing.
Hypovolemia causes increased risk of anaesthesia related hypotension and decreased tissue perfusion.
Electrolyte levels should also be taken care of before surgery as early sampling just after dialysis, before equilibration
may show hypokalemia. This may lead to unnecessary exogenous potassium supplementation.
Conversely, fasting causes hyperkalemia (due to decreased insulin levels in the body).
For emergency surgeries there may not be sufficient time to dialyze the patients preoperativey.
Therefore to avoid any complications, electrolyte abnormalities must be managed conservatively with particular care
paid to intraoperative fluid balance in such patients.

32. 4.PAEDIATRIC SURGERY
Infants and children are different from adults.
• Fluid management: A critical element in paediatric surgery because infants and children are sensitive to
even small degree of dehydration Higher requirement of water and electrolytes/ kg body weight
• Inability to excrete water load due to immature kidneysoverload
• Complex surgical procedures Rapid change of fluid requirement Frequent assessment and
modification of fluid therapy.
• In OT rapid change in requirements during:
- conduct of anaesthesia and surgery
-change in temperature
-metabolism and volume shift(as in trauma, hemorrhage, tissue exposure) intracompartmental fluid shift
• Requires fluid replacement with a solution that compensates for energy, water, protein and electrolyte
losses.
• Anaesthetist should be alert for obvious fluid loss , hidden (insensible fluid loss and third space loss.

33. Pharmacology and clinical
basis if iv fluids

34. Classification of fluids
• Maintanence fluid: They replace fluid lost from lungs, skin, urine and faeces. They are poor in
salts thus maintainence should be hypotonic with plasma sodium. Eg - 5% dextrose, dextrose
with 0.45% NaCl solution
• Replacement fluids: They are used to correct body fluid deficit caused by losses such as
gastric drainage, vomiting, diarrhoea, fistula. Eg - isotonic saline, dns, ringers lactate,
isolate- M, Pand G.
• Special fluids- Used for special indications such as hypoglycemia, hypokalemia and
metabolic acidosis. Eg- 25% dextrose, inj sodium bicarbonate, inj potassium chloride.

36. CRYSTALLOIDS
• Electrolyte solution with small molecules that can diffuse freely throughout the extra cellular
space
• Smaller in size than colloid
• Relatively low tendency to stay intravascular
• Principal component is inorganic salt sodium chloride
• 75 to 80% of infuse crystalloid is distributed in interstitial space
• Volume resuscitation with crystalloid fluid, expand interstitial volume rather than plasma volume
• Example: isotonic saline, lactated Ringer’s solution etc

37. Ringer’s lactate
• Composition: 1 L of fluid supplies sodium, 130 mEq, calcium 3 mEq, potassium 4 mEq,
bicarbonate 28 mEq, chloride 109 mEq
• INDICATIONS:
• Correction of severe hypovolaemia with large fluid volume
• Replacing fluid in post-operative patients, burn, fractures, peritoneal irrigation, etc.
• Diarrhoea induced hypovolemia with hypokalemic metabolic acidosis
• In diabetic ketoacidosis, as it provides, glucose free water with added advantage of supplying
potassium
• For maintaining normal extra cellular fluid volume and electrolyte balance during and after
surgery

38. CONTRA INDICATIONS:
• Inliverdisease,severehypoxaemiaand shock,lactate mechanism isseverelyimpaired.Ringer Lactate
infusioncan lead tolactic acidosis insuch patients.
• SeriousCHF lactic acidosis takesplace which ismoreinhearttissues.Lactate givencannot be utilised,so it
worsenstheproblem.
• Addison’sdisease
• Severemetabolic acidosis whereconversionfromlactate tobicarbonate isimpaired,so ringer lactate may
worsenmetabolic acidosis.
• Invomitingorcontinuous nasogastric aspiration:herehypovolaemia isassociated withmetabolic alkalosis
as RLprovidesbicarbonate itwillworsenmetabolic alkalosisand thereforenotpreferred.
• Along withblood transfusionbecause calcium intheRLbinds withcitrateanticoagulant presentin blood.Thiscan
cause inactivation of anticoagulant and formationof clots inthedonor blood.
• Calcium inRLalsobindswithcertaindrugslike (amphotericin,ampicillin)and reducestheirbioavailability and
efficiency.

39. Isotonic saline (0.9% NaCl- normal saline)
• One litrecontains:sodium 154mEq,Chloride 154mEq
• Thisfluid is chiefly distributed in extracellular fluid,itincreases the intracellular fluid substantially.Thus isotonic saline is very
useful inraising BPinpatient withhypovolemic shock.
• INDICATIONS:
• Indiarrhoea, vomiting,excessive diuresis or excessive perspiration.
• Treatmentof hypovolemic shock
• Treatmentof alkalosis with dehydration
• Inseveresalt depletion or hyponatremia when rapid sodium correction isnecessary.
• Initialfluid therapy indiabetic ketoacidosis.
• Treatmentof hypercalcemia.
• Irrigation forwashingof body fluids
• As vehicle for certain drugs and can be givensafely withblood .

40. • CAUTIOUS USE:
• Cautious use in hypertensive or preeclampsia patients, patients with oedema due to CHF,
renal disease and cirrhosis.
• Careful administration to very young or elderly patients.
• Dehydration with severe hypokalemia: In severe hypokalemia there is deficit of even ICF
potassium so infusion of isotonic saline, without additional potassium supplementation, will
aggravate electrolyte imbalance of ICF

41. 5%Dextrose
• 1litre contains 50gms glucose that provides 170 kcal.
• It corrects dehydration and supplies energy. After glucose consumption the remaining fluid
gets distributed in all compartments of body proportionately.
• INDICATIONS:
• Widely used for prevention and treatment of dehydration
• For pre and postoperative fluid replacement
• For treatment or prevention of ketosis in starvation, diarrhoea, vomiting and high grade fever
• Correction of hypernatremia due to pure water loss(eg: diabetes insipidus). Hypernatremia
due to salt poisoning or excessively use of electrolyte solution needs infusion of 5% dextrose
with furosemide to promote Na excretion and correction of Hypernatremia .

42. CONTRAINDICATIONS:
• Cerebral edema: As it’s hypotonic nature 5
%dextrose aggravates cerebral oedema.
• Neurosurgical procedure: As 5
%dextrose increases ICP it can cause damage during neurosurgery and thus
must be avoided.
• Acute ischemic stroke- Hyperglycemia aggravates cerebral ischemic brain damage
• Hypovolemic shock- Fast replacement by large volumes of D-5
%can lead to hyperglycaemia and osmotic
diuresis leading to increased urine output. Thus correction of dehydration be delayed.
• Hyponatremia and water intoxication: By providing electrolyte free water 5
%dextrose worsens both conditions.
• Hypernatremia :Fast infusion of 5
%dextrose rapidly corrects Hypernatremia but this correction occurs slowly in
brain cells .This leads to serious or permanent neurological damage. Rapid infusion of dextrose leads to
osmotic diuresis, which can aggravate Hypernatremia.
• Blood transfusion: Dextrose and whole blood should not be given in same in line as hemolysis and clumping can
occur.
• Uncontrolled diabetes and severe hyperglycemia.

43. Dextrose saline(DNS)- 5%dextrose with 0.9% NaCl Solution
• 1litre fluid contains: glucose 50gm, chloride 154mEq, sodium 154mEq
• Has advantages of both dextrose( provides energy) and isotonic saline (to provide salt).
• INDICATIONS:
• Correction of salt depletion and hypovolemia with supply of energy.
• Correction of vomiting or nasogastric aspiraton induced alkalosis and hypochloremia along with supply
of calories.
• Fluid is compatible with blood transfusion.
• CONTRAINDICATIONS:
• Use cautiously in anasarca
• Hypovolemic shock as large volume fluid is required here and it will cause effects similar to dextrose

44. COLLOID SOLUTION
• These are large molecules so when infused into vascular space they are retained within the
vascular system unlike crystalloids, thus they are more effective as plasma volume
expanders. They are 3 times more potent than crystalloids for increasing vascular volume
and supporting cardiac output.
• Thus when blood or plasma is not available immediately, infusion of colloids to correct
circulatory fluid volume is vital and often life saving
• Example: Albumin, dextran, hydroxyethyl starches, gelatin.
• Risks: allergic reaction, coagulation problems . Also they are costlier than crystalloids

45. COLLOIDS: Classification
NATURAL
1. Fresh frozen plasma
2. Albumin 5%,20%,25%
3. Plasma protein 4%-5%
4. Ivig
SYNTHETIC
1. Dextrans eg. Microspan 40 & 70
2. Gelatins eg. Haemaccel, Gelofusin
3. Hydroxy Ethyl Starch(HES)
eg. voluven 6%

46. ALBUMIN
• Synthesised only in the liver and has half life of approximately 20 days.
• Principle determinant of plasma colloid osmotic pressure (75% of the osmotic pressure)
• Principle transport protein in blood
• Maintain the fluidity of blood by inhibiting platelet aggregation.
• 5% albumin has COP of 20 mmHg and expands plasma volume to same as volume infused.
• 20% albumin has COP of 70mmHg and expands plasma volume by 4-5 times the infused volume.
• Dose(g)= (2.5-actual albumin concentration) x (kg x 0.8)
2.5- desired concentration of albumin
0.8- coefficient to calculate volume of plasma

47. Indications:
• Emergency treatment of shock specially due to loss of plasma
• Acute management of burns
• Fluid resuscitation in intensive care
• Clinical situations of hypoalbuminemia
- following paracentesis
- patients with liver cirrhosis
- after liver transplantation
• Spontaneous bacterial peritonitis
• Acute lung injury
• Correction of diuretic resistant nephrotic syndrome
• In therapeautic plasmapheresis, albumin is used as an exchange fluid to replace removed
plasma

48. PRECAUTIONS AND CONTRAINDICATIONS
• 20% albumin should not be used for volume resuscitation in patients with blood loss.
• Contraindicated in severe anemia and cardiac failure
• Should not be used as parenteral nutrition
• Cost effectiveness: Albumin is expensive as compared to synthetic colloids
• Volume overload: In septic shock the release of inflammatory mediatiors has been implicated
in increasing the ‘leakiness’ of the vascular endothelium. The administration of exogenous
albumin may compound the problem by adding interstitial edema.

49. GELATIN POLYMERS( HAEMACCEL)
• Gelatin is large molecular weight protein formed from hydrolysis of bovine collagen
• Molecular weight ranges from 5000 to 50,000
• Rapidly excreted by kidney
• t- half: 2.5 hours
• Duration of action is smaller compared to both albumin and starches.
• INDICATIONS:
• Rapid plasma volume expansion in hypovolemia
• Volume preloading in regional anaesthesia
• Priming of heart lung machines

50. ADVANTAGES:
• Cost effective: cheaper as compared to albumin and other synthetic colloids.
• No limit of infusion: no upper limit of infusion as compared to starches and dextrans.
• Less effect of renal impairment: Gelatins are readily excreted by glomerular filtration as they
are small sized molecules.
• DISADVANTAGES:
• Anaphylactoid reactions: Gelatins are associated with higher incidence of anaphylactoid
reactions compared to natural colloid albumin.

51. HYDROXYETHYL STARCH
• HES are derivatives of amylopectin, which is a highly branched compound of starch.
• Chemically modified polysaccharide
• Long chains of branched glucose polymers substituted periodically by hydroxy radicals(OH), which resist
enzymatic degradation.
• HES elimination involves hydrolysis by amylase enzymes in the bloodstream, which cleave the parent
molecule until it is small enough to be cleared by the kidneys.
• INDICATIONS: stabilization of systemic hemodynamics.
• ADVANTAGES: cost effective, less anaphylactic reactions
• DISADVANTAGES: increase in serum amylase during and 3-5 days after discontinuation.
• Affects coagulation by prolonging PT, APTT, and bleeding time by lowering fibrinogen, decreased platelet
aggregation, VWF, factor VIII.
• Associated with oligouria, increased creatinine and acute kidney injury in critically ill patients
• Accumulates in RES and causes pruritis

52. DEXTRANS
• Highly branched polysaccharide molecule.
• These glucose polymers are produced by bacterium(leuconostoc mesenteroides) incubated in
sucrose medium by bacterial dextran sucrase
• 6% solution has avg molecular weight of 70,000(Dextran 70)
• 10% solution has avg molecular weight of 40,000( Dextran 40)
• Effectively expand intravascular volume– dextran 40 produces greater plasma expansion than
dextran 70 but has short duration(6 hrs) and rapid renal excretion.
• Antithrombotic effect- inhibits platelet aggregation
• Improves microcirculation independent of volume expansion by decreasing viscosity of blood
• Renal excretion
• Colloid osmotic pressure 40mmHg

53. INDICATIONS:
• Improves microcirculatory flow in microsurgical reimplantations also and used for DVT
prophylaxis.
• Extracorporeal circulation: used in extracorporeal circulation during cardiopulmonary bypass
• Correction of hypovolemia -from burns, surgery, trauma
• CONTRAINDICATIONS:
• Renal failure
• Severe CHF
• Bleeding disorders- Thrombocytopenia, hypofibrinogenemia
• Severe dehydration
• Known hypersensitivity to dextran

55. Composition com used intravenous fluids
Electrolytes Ringers Isolyte P Plasmalyte Albumin Hetastrach
(meqL-1) lactate 5t‹ 6%
Na* 130 140
145ż15
K+ 21 <2.5
CI 154 109 21 98 100 154
Acetate 24 27
Lactate 28
Glucose
Phosphate
(mg%)
Osmolarity
(m0smL-1)
308 274 295 252 330 310

56. REPLACING BLOOD LOSS:
• Ideally, blood loss should be replaced with sufficient crystalloid or colloid solutions to maintain
normovolemia until the danger of anemia outweighs the risk of transfusion.
• At that point, further blood loss is replaced with transfusion of RBCs to maintain hemoglobin
concentration ( or hematocrit) at an acceptable level.
• There are no mandatory transfusion triggers. The point where the benefits of transfusion outweigh
its risks must be considered on individual basis.
• The most commonly used method for estimating blood loss is measurement of blood in the
surgical suction container and visual estimation of the blood on surgical sponges and laparotomy
pads ( lap sponges).
• A fully soaked “4x4” is generally considered to hold 10ml of blood, whereas a soaked “lap” may
hold 100 to 150 ml.
• Ideally, transfusions are not recommended until the hematocrit decreases to 24% or lower ( hB< 8.0
g/dl ), but we should take into account the potential for further blood loss, rate of blood loss, and
comorbid conditions (eg: cardiac condition)

57. CALCULATION OF ALLOWABLE BLOOD LOSS:
• Average blood volumes
AGE BLOOD VOLUME
Neonates-
Premature
Full term
95ml/kg
85ml/kg
Infants 80ml/kg
Adults-
Men
Women
75ml/kg
65ml/kg

58. • Estimate blood volume from above table.
• Estimate the red blood cell volume (RBCV) at the postoperative hematocrit (RBCV Preoperative)
• Estimate RBCV at hematocrit of 30% (RBCV 30%), assuming blood volume is maintained.
• Calculate the RBCV lost when the hematocrit is 30%, RBCV lost= RBCV Preoperative- RBCV 30%
• Allowable blood loss= RBCV lost x 3
• For eg: A 60kg woman has a hematocrit of 35% . Calculate the blood required to decrease her hematocrit to
30%?
• So, estimated blood volume =65ml/kg x 60kg =3900ml
• RBCV 35 =3900x 35% =1365 ml. RBCV 30= 3900x 30%= 1170
• RBCV lost = 1365-1170= 195 ml.
• Allowable blood loss = 3x195= 585 ml

59. THANKYOU