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1. Dr Ruwan Parakramawansha
MBBS, MD, MRCP(UK),MRCPE, DMT(UK)
(2013/01/30)
INTRAVENOUS FLUIDS
&
ORAL REHYDRATION SOLUTION

2. LEARNING OUTCOMES..
By the end of this lecture you will be able to,
– List different types of IV fluids
– Identify different methods of classifying i.v. fluids
– Understand differences in fluids in relation to their distribution in
different fluid compartments of the body
– Describe indications for IV therapy
– Outline complications of IV therapy
– List constituents of ORS

3. FLUID DISTRIBUTION IN THE
BODY
 Total body water (TBW)
In males – 60% of body weight
In females – 55% of body weight
e.g. In a 60kg male – TBW is 36L

4. TBW = 60% OF BODY WEIGHT
ICF ECF
40%
05%
15%
Plasma
Interstitial
Fluid

5. TYPES OF I.V. FLUIDS
1. Crystalloids vs. Colloids
CRYSTALLOIDS COLLOIDS
Normal (0.9%) saline Human Albumin
Ringer's lactate solution
(Hartmann's' solution)
Gelatin solutions
(Haemaccel,Gelafundin )
5% Dextrose Dextran
Hydroxyethyl starches
(Hetastarch)

6. TYPES OF I.V. FLUIDS
2. Hypotonic, Isotonic and Hypertonic
solutions
HYPOTONIC
SOLUTIONS
ISOTONIC
SOLUTIONS
HYPERTONIC
SOLUTIONS
0.45% (N/2) Saline Normal (0.9%) saline 3% Saline
0.18% (N/5) Saline Hartmann's' solution Mannitol
5% Albumin 20% Albumin

7. TYPES OF I.V. FLUIDS
3. Balanced vs. unbalanced intravenous fluids
UNBALANCED SOLUTIONS BALANCED SOLUTIONS
0.9% Saline Hartmann's' solution
Dextrans

8. TYPES OF I.V. FLUIDS
4. Natural vs. Synthetic
NATURAL SOLUTIONS SYNTHETIC SOLUTIONS
Human Albumin Gelatin solutions
(Haemaccel,Gelafundin )
Fresh Frozen Plasma Hartmann’s solution
Dextran

9. CRYSTALLOIDS
 Consist of inorganic ions and small organic molecules
dissolved in water
 Either glucose or sodium chloride (saline) based.
 May be isotonic, hypotonic or hypertonic
 Both water and the electrolytes in the crystalloid solution
can freely cross the semi permeable membranes of the
vessel walls into the interstitial space

10. Normal Saline (0.9% NaCl)
 Contains sodium and chloride ions in water and it is
isotonic with extracellular fluid
 Cell membrane is impermeable to Na+ and Cl- ions
owing to the presence of the energy dependant
Na+ /K+ - ATPase
 Intravenous infusion of an isotonic solution of sodium
chloride will expand only the extracellular compartment

11. Normal Saline (0.9% NaCl)
 Na+ is the main solute in ECF saline is well suited to
replace ECF fluid losses
e.g. dehydration due to nausea/vomiting
 Na+ and Cl- freely moves across vascular membrane
into the interstitium.

12. Normal Saline (0.9% NaCl)
 Remain in the intravascular space for only a short
period before diffusing across the capillary wall into the
interstitial space.
 1 liter infusion of normal (0.9%) saline will result in
~ 250 ml expansion of the circulating volume.
 Achieve equilibrium in 2-3 hours.

13. Normal Saline (0.9% NaCl)
Indications:
1. Replacement of fluids in hypovolaemic or
dehydrated patients ( Needs 3  blood loss)
2. A small amount of saline as a special adjunct can
be used to keep the veins open for medication
administration
3. As the initial plasma expander in blood loss while
blood is typed and matched

14. Normal Saline (0.9% NaCl)
Adverse Effects
1. Fluid overload (peripheral and pulmonary
oedema)
2. With high volume administration,
• Dilutional reduction of normal plasma components such
as calcium and potassium
• Dilutional coagulopathy
• Hyperchloraemic acidosis
3. Diuresis.

15. 5% Dextrose
– Initially behave as an isotonic solution.
– Glucose is soon metabolized, leaving behind
water making the solution hypotonic.
– Water freely moves between intravascular,
interstitial and intracellular fluid compartments till
the osmolalities become the same.

16. Indications:
1. To maintain water balance ( In pure water deficit and
for patients on sodium restriction)
2. To supply calories ( ~ 200kcal/l)
 An adult require ~2500 kcal/day
 Hence, glucose alone can’t meet the need.
 Would need >10 liters of 5% glucose to supply
all calories !!
5% Dextrose

17. 5% Dextrose
Adverse effects:
1. Causes red cell clumping (cannot be given with
blood).
2. May cause water intoxication
3. Can cause hyponatraemia

18. Ringer’s Lactate
 A balanced isotonic electrolyte solution.
 Similar to 0.9% saline in all aspects except,
– Contains sodium, chloride, potassium, calcium and
lactate in water. ( “physiological”)
– Prevents dilutional reduction of normal plasma
components such as calcium and potassium
– Avoids hyperchloraemic acidosis ( Lactate converted
to bicarbonate in liver.)
–  Preferred to normal saline when large quantities of
volume infused rapidly

19. COLLOIDS
– Colloids contain large molecules such as proteins that do not readily
pass through the capillary membrane
– Remain in the intravascular space for extended periods
– These large molecules also increase the osmotic pressure in the
intravascular space

Cause fluid to move from the interstitial and intracellular space to the
intravascular space
–  Often referred to as volume expanders

20. COLLOIDS
– Colloids stay in the vascular compartment for a longer
time compared to crystalloids
– Administered in a volume equal to the volume of blood
lost.
COLLOIDS NORMAL SALINE
HALF LIFE IN INTRAVASCULAR
COMPARTMENT
3-6 hrs 20-30 min

21. INDICATIONS
1. When rapid expansion of plasma volume is
desirable
e.g. in haemorrhage prior to blood
transfusion
2. For fluid resuscitation in the presence of
hypoalbuminaemia
3. In large protein losses e.g. in burns

22. Gelatins
 Prepared by hydrolysis of bovine collagen.
a). Gelafusine  - succinylated gelatin in isotonic
saline
b). Haemaccel - urea-linked gelatin and polygeline
in an isotonic solution of sodium chloride with
potassium and calcium.
 Theoretical risk of transmitting bovine spongiform
encephalopathy. (new-variant Creutzfeldt-Jakob
disease)
 Volume expanding effect lasts 2-3 hrs.

23. Dextrans
 High molecular weight D-glucose polymers prepared
from the juice of sugar beets.
 Preparations of different molecular weights
e.g. Dextran 40 (MW 40,000)
Dextran 70 (MW 70,000)
 Volume expanding effect lasts 5-6 hrs.

24. Dextrans
 Causes haemostatic derangements
– Factor VIII activity is reduced
– plasminogen activation and fibrinolysis is increased
– platelet function impaired
 Interfere with blood cross matching
 Alter laboratory tests
e.g. Plasma glucose, plasma proteins

25. Hydroxyethyl starches
 Synthesized from amylopectin(a D-glucose polymer with
a branching structure) derived from maize or sorghum.
 The larger molecular size leads to prolonged
intravascular retention compared to other colloids.
e.g. Hetastarch, Pentastarch

26. Human Albumin
 Two preparations 5% albumin (isotonic) and 25%
albumin (Hypertonic)
 20% albumin expands the plasma volume up to five
times the volume infused.
 Heat treated -  no risk of transmitting viral infections.
 Reduce ionized calcium level.

27. 27
PHYSIOLOGY
- Water is absorbed along the osmotic gradient created by
shift of electrolytes mainly Na+ and Cl-
- One form of sodium absorption occurs coupled to glucose.

28. In Diarrhoea……..
 Imbalance between absorption and secretion of fluid
and electrolytes.
 Prompt fluid replacement can prevent dehydration
and mortality( esp. in children)
 Na+ - K+ ATPase
 Na+ - Glucose co-transport unaffected
unaffected

29. 29
THE “NEW” WHO/UNICEF
ORS FORMULA
 A reduced osmolarity formula.
 Contains reduced amounts of glucose and sodium.
 Further reduces….
- stool out put
- vomiting
- unscheduled supplemental intravenous therapy
 Associated with increased risk of hyponatraemia

30. 30
WHO/UNICEF
LOW OSMOLARITY ORS FORMULA
Anhydrous
Glucose
13.5 g/l
Sodium chloride 2.6 g/l
Potassium
chloride
1.5 g/l
Sodium citrate 2.9 g/l