3. Objective of class?
By the end of the class we should be able to tell the:
1. Contents of Isolyte and their preparations.
2. pharmacological basis of Isolyte and their preparations.
3. Indications of Isolyte and their preparations.
4. contraindications of Isolyte and their preparations.
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5. Physiological Basis :
During vomiting or continuous Gastric Aspiration there is loss of gastric
juice.
Gastric juice contains 60 mEq/L sodium, 10 mEq/L Potassium and 130
mEq/L chloride along with acidic content.
So vomiting or continuous gastric aspiration will lead to Hypochloraemic,
Hypokalemic Metabloic Alkalosis.
Isloyte-G is gastric replacement solution. It provides all electrolytes lost by
gastric juice, corrects alkalosis and provides calories.
Ammonium ions in Isolyte-G are converted into urea and Hydrogen ion by
liver. H+ ion produced will replace the deficit of H+ ion caused by loss of
gastric juice .
ISOLYTE-G IS THE ONLY I.V FLUID WHICH DIRECTLY
CORRECTS METABLOIC ALKALOSIS OF ANY NATURE.
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6. INDICATIONS :
1. In vomiting and continuous gastric aspiration to replace loss of
gastric juice.
2. In treatment of Metabolic Alkalosis due to excessive administration
of sodium bicarbonate or aggressive diuretic therapy.
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7. CONTRAINDICATIONS :
1) HEPATIC FAILURE- in severe liver disease ammonium ions in
Isolyte-G will not be converted into H+ ion. Accumulation of such
unchanged ammonium ions may precipitate hepatic pre-coma in severe
liver disease. Moreover, this process of conversion of ammonium ions
into H+ ions will be an additional load to the already sick liver cells.
2) RENAL FAILURE: Isolyte-G may aggravate Uremic Acidosis ( due
to addition of H+ ions) and may lead to Hyperkalaemia in renal failure.
3) METABLOIC ACIDOSIS: By providing H+ ions, Isolyte-G will
aggravate MA.
4) SEVERE VOMITING WITH SHOCK : it carries the risk of
Hyperkalaemia due to its high K+ concentration and poor ability to raise
BP due to comparatively low Na+ Concentration.
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9. Pharmacological basis :
Isolyte-M is the richest source of Potassium (35mEq), so very useful to
treat hypokalaemia. However, always ensure good urine output or
normal renal status before its infusion.
Proportion of electrolytes in Isolyte-M is almost similar to the
maintenance requirements of the body. Additionally, it corrects acidosis
and supplies energy.
So this fluid fulfils the needs of the body electrolytes, pH maintenance,
caloric supply and water replacement and so it is ideal fluid for
maintenance fluid therapy.
As concentration of Sodium is low ( 40 mEq/L) ,it should be avoided in
Hyponatraemia. It is not preferred IV fluid in patients with significant
salt and water depletion.
M Maintenance
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10. Indications :
1) For parenteral fluid therapy, it’s the ideal maintenance fluid.
2) To correct hypokalaemia (k+=35meq) secondary to Diarrhoea, bilious
vomiting, prolonged infusion of potassium free IV fluids, ulcerative
colitis etc.
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11. Contraindications :
1. RENAL FAILURE: cautiously used or totally avoided in presence
of significant renal failure( ARF/ CRF) due to potential risk of
hyperkalaemia.
2. HYPONATREMIAAND WATER INTOXICATION: As Na+
concentration of Isolyte-M is much low, it should be avoided.
3. ADRENOCORTICAL INSUFFICIENCY : These patients have
abnormally high potassium concentration and therefore should not
receive fluids with high potassium.
4. BURNS: In patients with severe burns potassium concentration may
be abnormally high due to tissue destruction and Acidosis.
(Moreover, such patients require fluid with high Sodium
concentration such as RL rather than hypotonic fluids like Isolyte-M)
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13. PHARMACOLOGICAL BASIS :
oIsolyte-P is designed to suit maintenance fluid requirement of children.
oIt provides electrolytes, maintains pH, supplies calories and replaces
water deficit.
oAs compared to adults, children need more water and same electrolytes.
oSo Isolyte-P provides almost double water but same electrolytes as
Isolyte-M. Roughly, Isolyte-P has half concentration of electrolytes as
compared to Isolyte-M.
oIsolyte-P can be used in adults when there is chiefly water loss and only
small loss of electrolytes. (e.g.- hypernatremia)
isolyteP Pediatric
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14. Indications :
1) Chiefly, used as a maintenance fluid in infants and children to provide
daily water and electrolytes.
2) Excessive water loss or inability to concentrate urine ( e.g.- diabetes
insipidus)
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15. Contraindications :
1) Hyponatremia: Among all Sodium containing IV fluids, Isolyte-P has
least concentration of Sodium(20meq/l) so it will aggravate
hyponatraemia.
2) Renal Failure : Cautiously used In RF due to high concentration of
Potassium (20meq/l)
3) Hypovolemic shock: Isolyte-P is not the suitable i.v fluid to correct
hypovolemic shock ( as with diarrhoea and vomiting) due to
◦ low Na+ concentration, ability of isolyte-P to correct intravascular volume
and hypotension is poor
◦ In oliguric child, high K+ concentration is not safe.
◦ Rapid infusion of large volume of Isolyte-P can cause Hyperglycemia and
osmotic Diuresis even in child with fluid deficit, which is not desirable.
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17. PHARMACOLOGICAL BASIS :
Isolyte-E is an Extracellular replacement solution.
It has electrolytes similar to ECF except that it has double the
concentration of potassium and acetate ( which will get converted into
bicarbonate).
Patients on long term fluid therapy may develop magnesium
deficiency. So Isolyte-E is the only IV fluid available which will correct
MAGNESIUM deficiency.
So isolyte-E provides all ECF electrolytes, additional potassium and
acetate for maximum capacity to correct metabolic acidosis, supplies
energy and replaces water deficit.
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19. Contraindications :
1- Vomiting or continuous nasogastric aspiration will lead to metabolic
alkalosis due to to loss of H+ ions in gastric juice. As isolyte-E provides
maximum bicarbonate (acetate 47meq/l) among all commercially
available IV fluids, it will significantly aggravate metabolic alkalosis.
2- Metabolic alkalosis due to diuretics or sodium bicarbonate.
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21. REMEMBER :
1. RENAL FAILURE: ISOLYTE G/M/P are all AVOIDED
2. METABLOIC ALKALOSIS :
1. ISOLYTE-G IS THE FLUID OF CHOICE
2. ISOLYTE E IS CONTRAINDICATED IN IT
3. METABLOIC ACIDOSIS:
1. ISOLYTE G IS CONTRAINDICATED
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24. Crystalloid vs colloid
replacement :
Because crystalloids are
distributed in the ratio of 1:3
between intravascular and
extravascular space , therefore
replaced in a ratio of 3-4 times of
lost fluid. So for every 100 ml loss
of blood 300ml of crystalloid will
be required.
Replaced in a ratio of 1:1.
So for every 100 ml loss of blood
, 100 ml of colloid is sufficient.
CRYSTALLOID COLLOID
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25. Redistribution and evaporative
surgical fluid losses:
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Degree of tissue trauma Additional fluid requirement
Minimal ( eg- herrniorrhaphy) 0-2ml/kg
Moderate( eg- open cholecystectomy ) 2-4ml/kg
Severe( eg-open bowel resection) 4-8ml/kg
Pediatric : 10 ml/kg ( throughout the duration of the surgery )
26. Q) Why are vasopressors
diluted in 5% dextrose?
Firstly, we dilute vasopressors to prevent intense
vasoconstriction during drug infusion.
vasopressors are added with 5%D to limit the
significant loss of potency through oxidation.
It’s not mixed with an alkaline solution.
(rememeber: pH of D5 is the closest to the pH of
ADR)
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