2. ďOutline :
⢠Physiology of water balance.
⢠Classification of IV fluids.
⢠Crystalloids.
⢠Colloids
⢠Crystalloids vs colloids.
⢠Perioperative Fluid therapy
3. Distributionof body fluid
ďThe total body fluid is distributed mainly between two compartments:
1. The extracellular fluid.
2. The intracellular fluid.
ďThe extracellular fluid is divided into
⢠The interstitial fluid.
⢠The plasma.
⢠Transcellular fluid.
7. Daily fluid requirement :
Holliday 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
8. NORMAL FLUID AND ELECTROLYTE REQUIREMENT
1.WATER REQUIREMENT: Rough calculations.
A. Measurable loss (intestine + kidney) + 700ml.
B. 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.
2. Sodium- 100(60-150) mEq/day or 6gm of NaCl/day.
3. Potassium- 40-60mEq/day (20mEq= 1.5gm KCl)
daily urinary loss of potassium is about 20mEq/day.
4.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.
10. CLASSIFICATION OF IV FLUIDS :
1. Maintenance fluids â hypotonic solutions (To maintain patientâs hydration
& electrolyte intake that balance daily obligatory loss.)
⢠Dextrose
⢠Dextrose with 0.45%Nacl
2. Replacement fluids â (Correction of ongoing and additional losses that
occur during the course of therapy.)
⢠Isotonic saline
⢠DNS
⢠RL
⢠Isolyte M, P and G
3. Resuscitation-
For correction of shock with the achievement of an adequate perfusion
pressure.
11. CRYSTALLOIDS
ďCrystalloids are aqueous solutions of inorganic and small organic
molecules, the main solute being either sodium chloride or
glucose.
ďDepending on the concentration of the solute, manufactured crystalloid
solutions areâ
⢠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.
ďCrystalloids:
12. 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.
14. 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 plasmaâŚ.. 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)âŚâŚ.. Not chemically
normal.]
15. ďINDICATIONS:
⢠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
16. Disadvantagesof Normalsaline:
⢠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
chloride in 0.9% NaCl
⢠Decrease in renal perfusion has been observed presumably from
chloride mediated renal vasoconstriction.
17.
18.
19. RINGERâS LACTATE(RL)
ďCOMPOSITION:
ďśOne litre of fluid supplies:
k= 4,
ca = 3,
⢠Na = 130,
⢠cl= 109,
⢠HCO3=28
ďPHARMACOLOGICAL BASIS:
⢠It is most physiological fluid.
⢠Rapidly expands intravascular volume because of high Na (130) â effective in
hypovolemia
⢠Sodium lactate in RL is metabolized in liver to bicarbonate - useful in
correction of metabolic acidosis.
20. 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.
Contraindicationsand Precautions:
⢠In liver disease ,severe hypoxia and shock â causes lactic acidosis
⢠Severe metabolic acidosis where conversion from lactate to bicarbonate
is impaired.
⢠In vomiting or continuous nasogastric aspiration.
⢠Along with blood transfusion.
21. INDICATIONS:
⢠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
Protein-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.
22. Contraindications:
⢠Cerebral edema (hypotonic in nature)
⢠Neurosurgical procedures (increase ICP)
⢠Acute ischaemic stroke
⢠Hypovolemic shock (Hyperglycemia induced osmotic diuresis )
⢠Hyponatremia.
⢠Uncontrolled diabetes and severe hyperglycemia
ďPrecautions:
⢠I.V 5%D may cause local pain, vein irritation, and thrombophlebitis.
ďRate of administration
⢠0.5 gms/kg body wt/hour can be safely given without causing glycosuria.
⢠Equivalent to â â666ml/hour of 5%dextrose and 333ml of 10%dextroseâ
23. Dextrosewithhalfstrengthsaline(5%D+0.45%Nacl)
ďCOMPOSITION:
⢠One litre of fluid contains:
⢠Sodium - 77meq
⢠Chloride â 77meq
⢠Glucose - 50gm
Indications:
⢠Fluid therapy in paediatrics
⢠Early postoperative period
⢠As maintenance fluid therapy
Contraindications:
⢠Hyponatremia
⢠Severe dehydration due to diarrhoea and vomiting â need for large salt
replacement
24. 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.
ďContraindications:
⢠Severe hypovolemic shock.
DNS(5%D +0.9%NACL)
ďCOMPOSITION:
⢠One litre of fluid contains:
⢠Glucose - 50gm,
⢠Sodium - 154meq
⢠Cl - 154meq
25. ⢠It provides all electrolytes lost by gastric juice, corrects alkalosis and provides
calories.
⢠Ammonium ions are converted into urea and hydrogen ions in liver.
âIt is the only available fluid which directly corrects metabolic alkalosis.â
ISOLYTE-G
ďIndications:
⢠In vomiting and continuous gastric aspiration
⢠Metabolic alkalosis.
ďContraindications:
⢠Hepatic failure
⢠Renal failure
⢠Metabolic acidosis
⢠Severe vomiting with shock
26. 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).
27. ISOLYTE-M
⢠It is the richest source of potassium(35 meq/l)
⢠Ideal fluid for maintenance fluid therapy.
ďIndications
⢠Parenteral fluid therapy â ideal maintenance fluid.
⢠Hypokalemia secondary to diarrhoea, vomiting.
ďContraindications
⢠Renal failure.
⢠Hyponatremia and water intoxication.
⢠Adrenocortical insufficiency.
⢠Burns.
28. 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.
ďIndications:
⢠Diarrhoea
⢠Metabolic acidosis
⢠Maintenance of ECF volume preoperatively.
ďContraindications:
⢠Metabolic alkalosis
⢠Vomiting/nasogastric aspiration
29. DEXTR
O SE
(GM/L)
Na K Cl ACETATE LACTATE NH4 Cl Ca
5% DEXTROSE 50
0.9% SALINE 154 154
D â 5%,
0.45%SALIN
E
50 77 77
DNS 50 154 154
RL 130 4 109 28 3
ISOLYTE â G 50 63 17 150 70
ISOLYTE â M 50 40 35 40 20
ISOLYTE - E 50 140 10 103 47 5
30. Characteristicsof IV fluids
ďMost physiological iv fluid -
⢠Ringerâs lactate
⢠Because its constitution is similar to ECF
ďFluid that does not contain glucose â
⢠Isotonic saline and RL
⢠Preferred in diabetic patients
ďFluids that does not contain potassium
⢠Isotonic saline, DNS and dextrose solutions.
⢠Preferred in renal failure and hyperkalemia.
ďFluids to be avoided in renal failure
⢠Isolyte â M, P, G and E
⢠RL
31. ďIV fluids that does not contain sodium and chloride
⢠5%, 10% and 20% dextrose solutions.
ďIV fluids that can correct acidosis
⢠Isolyte â M, P and E
⢠Ringerâs lactate
- Acetate gets converted to bicarbonate
- lactate gets converted to bicarbonate.
ďIV fluid that can correct alkalosis
⢠Isolyte â G - Ammonium chloride gets converted to H+ and urea
ďFluids avoided in Liver failure
⢠RL â impaired conversion of lactate to bicarbonate.
⢠Isolyte â G - Impaired conversion of ammonium chloride to H+ and urea.
32. .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
NICEGUIDELINES
33. Resuscitation
⢠If patients need IV fluid resuscitation,
⢠use crystalloids that contain sodium in the range 130â154 mmol/l, with a bolus
of 500 ml over less than 15 minutes.
⢠Consider human albumin solution 4â5% for fluid resuscitation only in patients
with severe sepsis.
34. Routine maintenance
ďIf patients need IV fluids for routine maintenance alone, restrict the initial
prescription to:
⢠25â30 ml/kg/day of water and
⢠Approximately 1 mmol/kg/day of sodium and chloride and
⢠Approximately 50â100 g/day of glucose to limit starvation ketosis.
ďConsider prescribing less fluid for patients who:
⢠Are older or frail
⢠Have renal impairment or cardiac failure
⢠Are malnourished.
ďConsider delivering IV fluids for routine maintenance during daytime hours to
promote sleep and wellbeing.
35. 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,
36. Trainingand 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.
37. 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.
ďColloids:
Hydroxyethyl starches.
Gelatins.
Dextran.
Albumin.
38. 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
39. 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
ď5% 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.
40. Indications
⢠Plasma volume expansion - Acute hypovolemic shock ,burns and severe
albumin loss.
⢠Hypoproteinemia â in liver disease, malnutrition
⢠As an exchange fluid in therapeutic plasmapheresis to replace removed
plasma.
ďAdverse effects:
⢠Nausea ,vomiting
⢠febrile reaction and allergic reaction including anaphylactic shock.
ďPrecautions and contraindications:
⢠Fast infusion may cause volume overload and pulmonary edema.
⢠Severe anemia,
⢠cardiac failure.
41. 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 RBCâs.
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.
42. ďIndications:
⢠Correction of hypovolemia â 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.
ďContraindications:
⢠Severe oligo-anuria and renal failure.
⢠Severe CHF or circulatory overload.
⢠Hypersensitivity to dextran.
ďPrecautions
⢠Interferes with blood grouping and cross matching
43. HAEMACCEL
ďIt is a sterile , pyrogen free , colloidal plasma volume substitute which contains
a polymer of degraded gelatin with electrolytes.
ďComposition:
⢠Each litre contains : polymer from degraded gelatin 35 gm
⢠Na -145meq
⢠cl -145,
⢠ca -12.5,
⢠k -5.1
44. 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.
ďAdvantage
⢠Does not interfere with coagulation, blood grouping and cross matching
ďSide effects:
⢠Hypersensitivity reaction.
⢠Bronchospasm and fall in BP.
45. 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.
ďIndications:
⢠Hypovolemic shock
ďContraindications:
⢠CHF or impaired renal function
46. ďAdvantage
⢠Non antigenic.
⢠Does not interfere with blood grouping and cross matching.
⢠Less expensive than albumin.
⢠Expands plasma volume for a longer period.
ďDisadvantage
⢠Increases serum amylase and remains elevated for 3-5 days after use.
48. Monitoringfluid therapy:
ďParameters 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
49. CVPmonitoring
⢠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 â 10 cm of water
50. ďLOW CVP:
⢠True hypovolemia - blood loss and dehydration.
⢠Relative hypovolemia - caused by peripheral vasodilatation as in spinal
anesthesia , septicemia and anaphylactic shock.
ďHIGH CVP:
⢠Volume overload.
⢠Cardiac causes - CCF, cardiac tamponade , constriction pericarditis and TR.
⢠Pulmonary causes - embolism, tension pneumothorax , COPD ,Cor pulmonale
and IPPV.
51. Perioperative fluid therapy:
The goals of fluid therapy for major surgery are as follows:
1. 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 Clâ 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 individualâs physiologic variables and administering
fluid in sufficient quantities to achieve an improvement in these physiologic
variables, so-called goal-directed therapy.
52. Intraoperative fluid calculation:
Maintainence fluid(calculated from 4-2-1 formula)+fasting deficit(maintainence
fluidĂhours of fasting, 50% given in 1st hour, 25%given in 2nd hour, 25% given in 3rd
hour)+3rd 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.
53. GOAL DIRECTED THERAPY:
⢠Goal-improved tissue perfusion and clinical outcome
⢠Based on measuring key physiologic variables Cardiac output or Global Oâ
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
54. 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).
55. 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 Oâ 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.
56. 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.
57. 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:
58. 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.
59. 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.
60. 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:
ďź Pulmonary edema
ďź Fasciotomies in nonburned muscle compartments
ďź Raised IOP
ďź Conversion of superficial to deep burns
ďź Intraabdominal hypertension and compartment syndrome
61. 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.
62. 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.
63. 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.
64. HEPATIC FAILURE:
ď 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)
ď 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]
ď Excessive isotonic saline => salt and water overload=> further ascites
and edema formation.
ď Approach => Assess volume status and replace losses with
appropriate volumes of isotonic crystalloid, colloid, or blood but avoid
salt and water overload.
65. GERIATRIC:
ď Decrease in TBW, GFR, urinary concentrating ability, aldosterone, thirst mechanism, free-water
clearance.
ď Increase in antidiuretic hormone (ADH), atrial natriuretic peptide (ANP)
ď Renal capacity to conserve sodium is decreased.
ď Tendency to lose sodium in the setting of inadequate salt intake.
ď Decreased thirst response => risk for dehydration and sodium depletion.
ď Diminished ability to respond to an increased salt load => increased Na* retention during the
perioperative period.
ď Volume expansion SHOULD BE DONE CAREFULLY
66. OBSTETRICS PIH & PREECLAMPSIA
ď A clear association between positive fluid balance and the incidence of
pulmonary edema in this condition
ď Restricted volumes of IV crystalloid (80 mL/hr), and fluid balance observed
carefully.
ď Oliguria not treated by administration of large volumes of fluids if kidneys
normal.
ď Blood loss replaced with an appropriate volume of crystalloid, colloid, or
blood, depending on magnitude.
ď Invasive monitoring can be used to direct fluid therapy in severe
preeclampsia.
67. 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.