This document discusses fluid balance and fluid compartments in the human body. It defines key terms like total body water, extracellular fluid, intracellular fluid, osmolality, tonicity, electrolytes and explains the distribution and regulation of body water. It also describes hypovolemia, its causes, diagnostic criteria and management approaches for hemorrhagic and non-hemorrhagic hypovolemia. Common intravenous fluids are classified and their properties and uses are explained.

1. Fluid/s

2. Prof. Mridul M. Panditrao
Professor, Head & In-Charge of ICU
Dean of Academic Affairs
Department of Anaesthesiology & Intensive Care
Adesh Institute of Medical Sciences & Research
(AIMSR)
Adesh University
Bathinda, Punjab, India

3. Introduction
 Water is life!
 Journey of life starts in Water!
 Water is also a dramatic Paradox
 Too less or too much = Incompatible with life
 So the life is geared up around maintaining the
equilibrium !!
 In Fact entire life of the living thing is spent in maintaining
 The fluid balance
 pH balance

4. Introduction
 Quantitatively most important Body constituent
 Males = 60%
Of the total body weight
 Females 50%
 The lesser percentage in females because of larger fat
content.
 Water is found in each and every tissue of the body,
including bones and cartilages!

5. Body
Compartments Total Body Mass
Total Body Water (TBW)
Extra Cellular Fluid (ECF) Intra Cellular Fluid (ICF)
Solid Tissues
Intra Vascular
Fluid Interstitial fluid

6. Distribution of Body water
Intra-Vascular Compartment
5%
Interstitial Compartment
15%
Intra- Cellular Compartment
40%
Tissues
40%
Percentage Distribution of Various Body Compartments
Intra-Vascular Compartment Interstitial Compartment Intra- Cellular Compartment Tissues

7. Definitions
Total Body Water (TBW) :
 The sum of intracellular water and extracellular water (volume)
 The latter consisting of
 the interstitial or tissue fluid
 the intravascular fluid or plasma.
 About 60% of body weight
http://medical-dictionary.thefreedictionary.com/total+body+water
http://www.medilexicon.com/medicaldictionary.php?t=99650

8. Definitions
 The Extra-Cellular Fluid (ECF): The water content found outside the
body cells
 Constitutes two major compartments
Inra-vascular & interstitial
 Also contain the trans-cellular fluids that are formed by active transport
processes
Include the fluids of the eye and the secretory glands e.g. saliva, GIT and sweat
glands
In the cavities and channels of the brain and spinal cord (Cerebrospinal fluid, CSF)
Lymph
In body cavities lined with serous (moisture-exuding) membrane and
In muscular and other body tissues
Ingested water or water produced by the body's metabolic processes (metabolic
water).
http://www.britannica.com/EBchecked/topic/199041/extracellular-fluid

9. Definitions
Intra Cellular Fluid ( ICF):
 a fluid within cell membranes of the tissue cells, throughout
most of the body
 containing dissolved solutes that are essential to
electrolytic balance and to healthy metabolism.
 Also called intracellular water
 constituting about 30–40% of the body weight.
http://medical-dictionary.thefreedictionary.com/
www.medilexicon.com/medicaldictionary.php?t=34113

10. Rule of 1/3
 Out of all the compartments in TBW
 We can manipulate only ECF Compartment
 More specifically only Intra-Vascular Compartment
 Quantity of ECF is 1/3rd of the TBW
 Quantity of Intravascular Compartment is 1/3rd of ECF

11. Intra Vascular Volume: Blood
 Blood Volume: is the volume of blood (both red blood
cells and plasma) in the circulatory system of any
individual.
 Effective Circulating Volume: that proportion of
Intra- vascular volume ( thus of ECF) that is effectively
perfusing the tissue cells
 It is in direct proportion to the
 ECF
 Solute Content dissolved in it ( esp. Na+ salts)
 Solutes hold the water in ECF

12. Solutes:
Solute: A substance dissolved in another
substance or water
both of in-organic as well as organic origin
Solutes in ECF: by and large of in-organic type
E.g. Na+
, Cl
-
, HCO3
-
,
Solutes in ICF: Mixture of Both
E.g. K+, Organic Phosphate esters( ATP, Creatine
Phosphate… etc.)

13. •Mole - A mole is the amount of a substance that contains the number
of molecules equal to Avogadro's number.
•The mass in grams of one mole of a substance is the same as the number of atomic mass units in one
molecule of that substance.
•i.e. the molecular weight of the substance expressed as grams)
•The mole (symbol: mol) is the base unit in the SI system for the amount of a substance
•Molality of a solution is the number of moles of solute per kilogram of
solvent
•Molarity of a solution is the number of moles of solute per liter of
solution
 Avogadro's number - this is the number of molecules in
one mole of a substance (ie 6.022 x 1023)

14. Osmole
The amount of a substance
that yields, in ideal solution
that number of particles = (Avogadro’s number)
that would depress the freezing point of the solvent by 1.86K

15. Osmolality & Osmolarity
 Osmolality: Osmolality is a measure of the number of
solute particles present in solution
 Is independent of the size or weight of the particles
 Expressed as : milliosmoles per kilogram of water ( m
Osmol/Kg)
 Osmolality of a solution is the number of osmoles of solute
per kilogram of solvent ( m Osmol/Kg)
 Osmolarity of a solution is the number of osmoles of solute
per liter of solution ( m Osmol/L)
http://www.anaesthesiamcq.com/FluidBook/fl2_3.php

16. Osmolality & Osmolarity
 The value measured in the laboratory is usually referred
to as the ‘osmolality’
 The value calculated from the solute concentrations is
reported by the laboratory as the ‘osmolarity’
 The Osmolar gap is the difference between these two
values

17. Tonicity
 Tonicity is the effective osmolality
 Is equal to the sum of the concentrations of the solutes
which have the capacity to exert an osmotic force
across the membrane
 Osmolality is a property of a particular solution and is
independent of any membrane
 Tonicity is a property of a particular solution in reference
to a particular membrane

18. Tonicity
 It is strictly wrong to say this or that fluid is isotonic with
plasma
 what should be said is that the particular fluid is isotonic
with plasma in reference to the cell membrane
 By convention, this specification is not needed in
practice as it is understood that the cell membrane is the
reference membrane involved.

19. Tonicity Vs. Osmolality
 refers to the relative
concentration of two solutions.
 hyperosmotic, means the
concentration of solutes
outside the cell is greater than
the concentration inside the
cell
• refers to what the cell
does in a certain
environment.
• If the environment is
hypertonic, the cell will
shrink due to water
leaving the cell.
• Hypotonic means water
enters the cell makes it to
expand and possibly
explode.
 Effect is same:
 If a hyperosmolar/ hypertonic solution was administered to a
patient, this would tend to cause water to move out of the cell.

20. Electrolytes: definition
An electrolyte
is a substance that ionizes when dissolved in suitable
ionizing solvents such as water
 This includes most soluble salts, acids, and bases
 Some gases, such as hydrogen chloride, under
conditions of high temperature or low pressure can also
function as electrolytes
 Cations: Positively charged e.g. Na+, K+, Ca++, Mg++
 Anions: Negatively Charged e.g. Cl-, HCO-, OH-, HPO4--
,SO4--
http://en.wikipedia.org/wiki/Electrolyte

21. Main Electrolytes per Compartment
Electrolytes (mEq/L) ECF: Cations ECF: Anions ICF: Cations ICF: Anions
Sodium Na+ 135 - 145 - 8 -10
Potassium K+ 3.5 - 5.5 148 -152
Calcium Ca++ 7 - 10 0.001
Magnesium Mg++ 1.5 - 4 40!
Chloride Cl- 95 -105 1-2
Bicarbonate HCO3 - 20 - 24 4-7
Phosphate HPO4 +
Sulphate SO4
145 - 155 5 - 9

22. Plasma Osmolality
 Plasma or Serum Osmolality is Number of solutes
dissolved in plasma
 Normal range is : 275 -290 m Osmols/ Kg of Plasma
 Equation for calculation:
 Plasma Osmolality = 2x S. Na + S. Glucose/18 + BUN/2.8
 Conversion factor for BUN = B. Urea(mg/dl) /2.14
 P. Osmol = 2x S. Na + S Glucose/18 + B. urea x 2.8/ 2.14

23. Body Water Regulation
Increase in osmolality stimulates osmo-receptors
in antero-lateral hypothalamic nuclei
Thirst
Neuro-hypophysis
ADH & AVP
Decreased excretion by increasing
re-absorption.

24. Insensible water loss
Skin = 400 - 450 ml/day
RS = 400 - 500 ml/day
GIT (Stool) = 100-200ml/daay
Sweat is not insensible loss
Total Minimal loss around 1L/day

25. Calculation
 Daily Total imperative requirement in a surgical patient/
person is
= absolutely required minimal Urine output + 800-1000 ml
 In a 60 kg male
 i.e. 0.6-0.7ml/kg/hr + 800-1000 ml
 40ml/hr = 1000ml + 1000 ml
 2000ml/24 hrs = 80 – 100ml/hr

26. Classification of I V Fluids
Blood and Products
I V Fluids
Non blood I V Fluids
Crystalloids Colloids
Glucose Containing
Electrolyte solutions
Mixed
Proteinous Non proteinous
Polygelins
• Haemaccel
• Gelofusin
Albumin
20% & 5%
Starches Dextrans
 HES
 PentaStarch
 Tetrastarch
Lomodex (Dextran 40)
Macrodex (Dextran 70)
Rheomacrodex (Dextran
110)

27. Relative tonicity
 Isotonic : R L, 1N NaCl,D5W (inside body becomes
hypotonic)
 Hypertonic: 5DNS, 5D in RL, 5D in ½ N NaCl, 3% NaCl
 Hypotonic: ½ N NaCl
 20% Albumin has osmotic effect 5 times its volume
i.e. 100 ml will increase plasma volume by 400-500ml
Given at the rate of 1-2 ml/min
Correcting fluid deficit is absolutely inperative
5% will increase only by 100 ml ( 0.5-1 ml/min)

28. Colloids: Dextrans
 Dextrans are branched polymers of Glucose
molecule
 40, 70 and 110 are, mol. Wts : 40000, 70000 and
110000 Daltons
 40 is 10% while 70 is 6%
 Act as Antithrombotic, by decreasing RBC
aggregation
 Total dose not more than 20ml/kg in 24 hrs
 Hyperglycemic effect
 Not commonly used nowadays

29. Colloids : starches
 Excellent Volume expanders
 All of the volume remains inside Intra vascular compartment
 Effect lasts for 4-6 hours
 Interference with platelet aggregation: HES> Penta> tetra,
Least
 Increase the volume by nearly 100 to 150 % depending upon
% conc.
 Tetrastarch: Voluven Better of all
 Made from corn starch: least antigenic
 Up to 35ml – 50 ml/ kg/ 24 hours can be given

30. Colloids: Polygelins
 Modified: degraded gelatin polymers
 Derived from animal bones
 Can expand plasma by 50%
 Do not have any interference with agglutination, platelet
aggregation
 Have been found have variety of allergic reactions :
minor to anaphylaxis
 Have been implicated in transmission of Creutzfeldt-
Jakob’s disease (Mad Cow disease) to humans
 Slowly becoming obsolete

31. Hypovolemia
 ECF Volume Reduced
 Extra renal
Hemorrhage
Gastro-intestinal
Skin
 Renal
Diabetes insipidus
Diabetes mellitus
Drugs: Diuretics
Hypoaldosteronism
Salt wasting nephropathies

32. Hypovolemia
 ECF Volume increased ( Low circulatory/Intra-Vascular volume)
 Decreased Cardiac Output
CCF
 Redistribution of Fluid
Decreased PCOP
Cirrhosis
Nephrotic Syndrome
Capillary leak
Ischemic Bowel: Third space loss
Ac. Pancreatitis
 Increased Venous Capacitance
Anaphylaxis
 Mixed of all
SEPSIS

33. Diagnostic Criteria
 S. Na: Low if both Na+H2O, High if only H2O
 BUN/ S. Creatinine raised & BUN: Creatinine ratio > 20:1
:: .. If Pre-Renal azotemia
 CVP: 2 tests
 Lower than normal (8 – 10 CM H2O) = In IPPV patient deduct PEEP of more than 5 cm
H2O :
 Volume Challenge: 250-500 ml of rapid infusion RL/NS will increase CVP, but cannot sustain it
more than 10 minutes.
 USG & IVC = correlation between
IVC size, Respiration & CVP
 IVC size decreases with respiration
IVC Size Respiratory
change
CVP cm
H2O
<1.5 Total Collapse 0-5
1.5 -2.5 >50% Collapse 6-10
1.5 -2.5 < 50% Collapse 11-15
>2.5 <50% Collapse 16-20
>2.5 No Change >20

34. Hemorrhagic Hypovolemia: Surgical
 Calculate Estimated Blood Volume (EBV): approx. 75-80 ml/ Kg
 Categorize the blood loss: Fromme - Boezaart Surgical Field Grading
Boezaart AP, van der Merwe J, Coetzee A. Comparison of sodium nitroprusside- and esmolol-induced controlled hypotension for functional
endoscopic sinus surgery. Canadian Journal of Anaesthesia 1995; 42: 373-6
F-B
Grade
% age of
EBV
Fluid to be
transfused
1 - 2 Less than
10
Maintenance with
NaCl/ RL=
1ml/kg/hr
3 10 - 20 Increase the rate
of Crystalloid =
2ml/kg/hr
4 20 – 25% Colloid
5 25% or
more
Stat Blood
transfusion

35. Management : Non Hemorrhagic Hypovolemia
 Intra-Venous Fluids : Irrespective of Na level.. Initial fluid is NS
 If Na low– 0.9% N NaCl
 If Hypernatremia : ½ N NaCl
 Strict I/O chart with Hourly urine record
 Choice of I V fluid as per I-V Compartment stay : 1 Liter
Type of fluid Intra vascular in
ml
Interstitium in ml Intra cellular in
ml
5% D/W 75-100 (10%) 230 - 260 ( 20-
23%)
670 (67%)
1 N NaCl 300 (30%) 700 (70%) 0 (0%)
1/2N NaCl 170 (17%) 500 (50%) 330 (33%)
Colloids 1000 (100%) 0 (0%) 0(0%)

36. According to indication
Pathology Choice of IV Fluid
Non-Hemorrhagic hypovolemic
shock
NaCl/RL/Colloids
Diarrhea RL/ NaCl
Vomiting Isolyte G, NaCl
DKA NaCl
Burns RL
Starvation 5% D/W
Maintenance Adult Isolute M
Maintenance Pediatric Isolyte P
Required Na = desired Na – actual Na x ( 0.6 x Body weight in Kg.): 0.5 females

37. Protocol
 Impossible to measure exactly the total deficit
 Empirically : RL or NaCl at the rate of 30ml/Kg bolus
 RL is preferred as less chances of Hyperchloremic metabolic
acidosis
 Strict watch on: vitals, CVP, Urine output, GCS, ABG
 Maintain CVP 8-12cm H2O
 Urine 0.5-0.6ml/kg/hr
 Improved sensorium
 Decreased Hematocrit and BUN: creatinine ration> 20:1
 Decreased Metabolic Acidosis

38. SIADH
 Syndrome of impaired water excretion with retention of
water leading to increase in TBW, hyponatremia but NO
CLINICAL OEDEMA
 Multiple aetio-pathgeneses: stress, surgery, anesthesia,
pain, sepsis, inflammatory process, tumors, CNS
disorders
 Low Na: 130, low osmolality < 270 mosm/L ,but
normovolemia
 Increased urine osmolality>100mosm/L,
urine Na> 40mEq/L
 Normal renal,endocrine, K levels and acid-base
balance

39. Correct underlying cause
Fluid restriction: < 800ml/day
Loop Diuretic
Hypertonic (3%) NaCl
High Protein diet will increase renal water
excretion
SIADH

40. DKA
 Triad: Hyperglycemia, Dehydration and Hyperketonemia with
Metabolic acidosis
 Deficit levels in DKA
 Fluid deficit: 100ml/Kg---- 50% replace with NaCl (ECF)
---- 50% replace with dextrose (ICF)
 Na 7-10 mEq/Kg
 K 3-5 mEq/kg
 PO4 5-7
 Ca 1-2
 Mg 1-2
 ABG: severe acidosis with HCO3 grossly reduced

41. DKA: Management
 A,B, C
 Fluid Therapy
 NaCl: 10-15ml/Kg/hr. up to 50ml/kg in first 4 hours
 1000ml in first 30 min : next 1000 in 1hour: next 1000 in next 2
hours: next 1000 in next 2-4 hours
 When Blood sugar to 250mg/dl: D5W 1000ml/ 8hourly : continue
with NaCl and D5W 1000 ml every 12 hours
 Nearly 6 liters fluid in first 24 hours
 Strict watch on CVP, I/O, urine, ABG(acidosis), sensorium, S. Na
levels
 Strict watch On S. K levels.

42. DKA : Insulin
Role of Insulin: if K > 3.3 mEq/Lit
 After intial NaCl infusion has started
 Initial Infusion of 0.15 Unit/Kg regular = 10 units/ hr
 Or Add 50 units in 50 ml NaCl
 6units/hr infusion initially
 Reduce to 5 units/hr when glucose < 500mg/dl
 Reduce to 4 units/hr when glucose < 400 mg/dl
 Reduce to 3 units/hr when glucose < 300 mg/dl
 Reduce to 2 units/hr when glucose < 200 mg/dl
 Maintain on 0.05-0.1unit/kg/ hr infusion
 Switch over to sub cutaneous once sugar <200, HCO3 >18

43. DKA: Potassium Replacement
 Despite total Body K deficit S.K is normal
 With Volume replacement the K level drops
 K <3.5 = KCl 40 mEq/L : Give 1 L of NaCl
 K 3.5- 5 = KCl 20 mEq/L :Give 1 L of NaCl
 K > 5 or Anuria NO KCl to be given
 EKG:
Tall Ts HyperKalemia &
Flat Ts and Us HypoKalemia

44. DKA: HCO3
 Not Recommended routinely
 Only if
pH <7, Shock/ Coma, CVS/RS , Hyper Kalemia
 If ABG not available:
 (24 - pt’s HCO3) x (0.5 x Wt. in Kgs.)
 If ABG available:
HCO3 required = BE x 1/3 of Body Wt. in Kg. & ½ correction

45. DKA : Supportive T/t
 O2 By mask/ Venti-Mask / ETT & IPPV
 CVP
 N G / Urinary Catheter = I/O Balance
 Colloid If MAP< 60 mmHg/ Syst BP< 90mm Hg
 Antibiotics/Gastric Prophylaxis/
 Mg and PO4 correction if required

46. Burns : Fluid Therapy
Goals:
 To Maintain tissue perfusion : confirmed by hrly urine
output
 To reduce the rate of catabolism or
 To overcome the negative effects of Catabolism
 If less than 20% burns = Oral fluids.. Exceptions facial,
hand and genital burns
 If more : Parkland’s formula = total vol. in first 24 hours.

47. Parkland’s Formula
 4ml/Kg/% burn for adult & 3ml/Kg/% burn for children
 Ringer’s Lactate only
 Total calculation to be transfused in first 24 hours
 50%( half the volume) given in first 8 hours
 Remaining 50% ( half) in next 16 hours
 Children:
 4 ml/kg/% burn in 0 – 10 kg
 40 ml/hr + 2ml/hr for 10 – 20 kg
 60 ml/ hr + 1ml/kg/hr for more than 20 kg

48.  Next24 hours: No crystalloids, 5% Albumin (Colloid)
 Up to 60% of estimated Plasma Volume
 D5W as maintenance for urine: 0.5 – 1 ml/hour
Modified Parkland formula
 Initial 24 hours R L 4ml/kg/ % burn
 Next 24 hours Colloid infusion 5% albumin 0.3 -1
ml/kg/% burns
Parkland’s formula

49. Conclusion
Fluid Therapy is the ‘ Make’ or ‘Break’ for many
patients.
Especially in evolving/ imminent or existing Crisis
Understanding and executing appropriate fluid
therapy is the most essential duty of a clinician
A small oversight or miscalculation can cause a
major disaster for the patient
Continuous updating of our knowledge is most
essential

50. Thank You!