For All Medical & Non Medical Students

1. DISORDERS OF WATER
&
ELECTROLYTE BALANCE
By
Santhosh Kumar .N
Asst.Professor
SIMS & RH, Tumkur

2. Dehydration
a) Simple dehydration
b) Dehydration due to combined water and Na+ deficiency
• Combined water and Na+ deficiency is more common then
simple dehydration
• Results from a net –Ve balance of water and Na+
• In this case water balance may be more –Ve than equal to,
or less –Ve than Na+ balance
Santhosh Kumar .N/ Dept.of Biochem/ SIMS&RH

3. Hypernatremic or
hyperosmolar dehydration
Normonatremic or
isomolar
Hyponatremic or
hyposmolar
Water balance is more
negative than Na+ balance
Equally negative If it is less negative
than Na+ balance
Causes of H2O & Na+
deficits
Increase in ECW osmolarity
causes water to move out of
the cell & contraction of
ICW volume occurs
Total water deficit is shared
by EC & IC compartment.
The EC volume
contraction is
intermediate.
No changes occurs
in ECW & ICW
osmolarity so that
water does not move
out of or into cells
ECW volume depletion
is largest with
increased ICW volume
Decrease in ECW
osmolarity causes water
to move into cells
Causes:
Excessive sweating
Water & food deprivation
Diuretic therapy
Osmotic diuresis with
glycosuria
Causes :
Vomiting
Diarrhea
Causes: More sweating
renal disease
Adrenocortical
insufficiency
Addison’s disease
Diuretic therapy

4. (Water Depletion)
 Diabetes insipidus
Wrinkled skin, dry mucous membranes, muscle
cramps , increase blood urea nitrogen &
hematocrit, with hypotension
and shock may occurs
Santhosh Kumar .N/ Dept.of Biochem/ SIMS&RH
Causes:

5. Treatment:
• Simple dehydration: patient is asked to drink plenty of
water, if not possible an isotonic solution of 5% dextrose
is given IV.
• Due to combined deficiency of water & electrolyte: An
isotonic solution of sodium chloride (Normal saline) is
given IV

6. EDEMA
• Due to excess water & Sodium content of the body, leads to
edema
• Occurs in water intoxication, excessive administration of
intravenous fluids, protein deficiency, increased secretion of
ADH, cancer & drugs
• Various liver diseases that result in decreased protein
synthesis also leads to edema.
Santhosh Kumar .N/ Dept.of Biochem/ SIMS&RH

7. Factors contributing to edema
• Inhalation of gases, inflammation (pneumonia) or respiration
burns may increase the permeability of pulmonary capillaries
with loss of proteins & fluids
Causes of edema:
Malnutrition,
Obstructed lymph flow,
Fluid accumulation in lungs
Left ventricular heart failure,
Early phases of congestive heart failure,
Glomerular nephritis,
Nephrotic syndrome,

8. Water intoxication / Overhydration
• Water intoxication results due to the retention of excess
water in the body which occurs
– Due to renal failure
– Excessive administration of fluids parenteral
– Hyper secretion of ADH (SIADH: syndrome of
inappropriate ADH secretion )
– Results in hyponatremia & hyposmolarity of ECW
with expansion of the ECW & ICW compartment
Santhosh Kumar .N/ Dept.of Biochem/ SIMS&RH

9. Symptoms
• Acute fall in serum sodium results in
Nausea, vomiting, headache,
Muscular weakness, confusion,
In severe case convulsions, coma and
even death can occurs

10. Investigations Reference
values
Clinical Interpretations
Increased Decreased
Sodium
(Na+ )
135 - 145
mEq/L
Hypernatremia: Cushing’s
syndrome, Prolonged cortisone
therapy.
Hyponatremia: Vomiting,
Diarrhea, Burns, Addison’s
disease & Severe sweating
Potassium
( K+)
3.5 - 5.1
mEq/L
Hyperkalemia; Renal failure,
Addison’s disease & Diabetic
coma , cardiac arrest & paralysis
Hypokalemia: Prolonged
vomiting, Severe diarrhea,
Cushing’s syndrome,&
muscular weakness
Chlorides
(Cl-)
96 – 110
mEq/L
Hyperchloremia: Dehydration,
Severe diarrhea, Renal tubular
acidosis, Cushing‘s syndrome &
Respiratory acidosis.
Hypochloremia:Vomiting,
Diarrhea, Respiratory
alkalosis & Excessive
sweating
Calcium 8.5 -
10.5mg/dl
Bone disorders , Acute &
Chronic renal failure
Hypo parathyroidism &
Acute pancreatitis

11. Thank Q
The End
Santhosh Kumar .N/ Dept.of Biochem/ SIMS&RH