This document discusses electrolyte composition and imbalances in the body. It provides tables showing normal electrolyte levels in extracellular fluid, intracellular fluid, and gastrointestinal secretions. It then discusses potassium, sodium, calcium, and magnesium in more detail, including their roles, regulation, causes of imbalance, signs and symptoms, and treatment approaches for hypo- and hyper- conditions. Treatment sections focus on correction rates and addressing underlying causes, organ dysfunction, or excess intake/losses as appropriate for each electrolyte imbalance.

1. ELECTROLYTE
IMBALANCE

2. Composition in body
compartments
Electrolyte ECF (mEq/l) ICF (mEq/l)
Sodium 135-150 10-18
Potassium 3.5-5.0 120-145
Calcium 8.5-10.5 mg/dl
Magnesium 1.5-2.4 30-50
Chloride 95-108 2-6
Phosphate 2.5-4.5 mg/dl 25-60
http://www.globalrph.com/index.htm

3. Composition of GI secretions
(mEQ/l) Sodium Potassium Chloride Bicarbonate
Saliva 10 25 10 30
Stomach 60-90 10-30 100-130
Duodenum 140 5 100
Mixed
gastric
aspirate
120 10 100
Ileum 140 5 100 30
Colon 60 30 40
Stool 35 3-12 20
Pancreas 140 5 75 115
Bile 140 5 100 35
Bailey&Love 26th ed., Schwartz 9th ed.

4. POTASSIUM
⚫Primary intracellular ion
⚫Regulates cell excitability
⚫RDA : 4700 mg (0.6-0.8mEq/kg/day)
⚫Regulated be renin-angiotensin-
aldosterone axis
⚫Relation to acid base balance(buffer)
potassium decreases by 0.3 mEq/l
for every 0.1 increase in pH

5. ETIOLOGY
HYPERKALEMIA HYPOKALEMIA
⚫ Increased intake
⚫ Increased secretion
⚫ Impaired excretion
⚫ Inadequate intake
⚫ Excessive excretion
⚫ GI losses
⚫ Misc

9. Treatment of hypokalemia
⚫Correction = 0.4× Body weight× deficit
⚫Oral / IV
⚫How much to correct?
⚫Peripheral/central line?
⚫Refractory cases?? Why?
⚫Co-existing hypokalemia and acidosis,
what to correct first?

10. Treatment of hyperkalemia
⚫Stop all oral and iv infusions of
potassium
⚫Stabilize the heart
⚫Role of bicarbonate??
⚫Short term measures
⚫Permanent measures

11. SODIUM
⚫Primary extracellular ion
⚫Vital for homeostasis and action potential
in the body
⚫Controls water movement in and out of
the vascular system
⚫Regulated byADH
⚫RDA : 2400mg (1-2mEq/kg/day)
⚫Serum osmolality
◦ 2×Na + BUN/2.8 + glucose/18
◦ 2×Na + Bl urea/6 + glucose/18

13. Hyponatremia
⚫Hypotonic/hypertonic
⚫Every 100 gm fall in glucose,
1.6mEq/l fall in na (transient h-na)
⚫Renal/ extra renal
⚫Volume status
⚫ADH – H-na – osmalilty
⚫SIADH

15. Treatment of hyponatremia
⚫Correction = 0.6(m)/0.5(f) × deficit × BW
⚫Na <110 or neurological symptoms
◦ 3% NS until Na >120 or symptom free
◦ Rate of correction 0.25 mEq/l/hr or 8
mEq/l/day
◦ Seizures are present, correction can be upto
4-5 mEq/l in first hour
◦ Central pontine myelinosis
Hypovolemia Euvolemia Hypervolemia
Salt and water Water restriction Salt & Water restriction
IV saline Loop diuretics

16. Hypernatremia
⚫Volume status
⚫Renal / extra renal
⚫Diabetes insipidus
⚫Sr.osmalality
⚫Rare for a thristy person to end up
with hypernatremia

18. Treatment of hypernatremia
⚫Volume status
⚫Rate of correction
◦ Acute – max of1-2 m Eq/l/hr
◦ Chronic – max of 0.5 mEq/l/hr
◦ Max of 8 mEq/l/day
⚫Diabetes insipidus
Hypovolemia Euvolemia Hypervolemia
NS/2 and D5 Water or D5 Salt restriction
Loop diuretics with
water

19. CALCIUM
⚫Regulated by PTH and Calcitonin
⚫Vitamin D plays a role in absorption
⚫Coagulation cascade, neuromuscular
function
⚫Ionic 50%, protein bound 40%, anion
bound 10%
⚫RDA: 1-2g
⚫Ionic ca = total ca + [0.8×(4.5-albumin)]
⚫Relation to acid-base balance
◦ Acidosis decreases protein bound ca levels

20. ETIOLOGY
HYPOCALCEMIA HYPERCALCEMIA
⚫ Post thyroid and neck
surgery
⚫ Endocrine
⚫ Renal failure
⚫ Hyperphosphatemia
⚫ Malignant disease
⚫ Nutritional
⚫ Blood transfusion
⚫ Inflammatory conditions
⚫ Endocrine
⚫ Renal dysfunction
⚫ Malignant disease
⚫ Nutritional
⚫ Granulomatous disease
⚫ Inherited disorders

22. Chvostek’s sign

23. Trosseau’s sign (carpopedal
spasm)

24. Treatment of hypocalcemia
⚫10ml of 10% calcium gluconate(1 gm)
f/b calcium infusion if necessary (0.5-
1.5mg/kg/hr)
⚫Gluconate preferred over chloride
⚫Hyperphosphatemia correction
⚫Refractory cases? Why?
⚫Oral supplementation with vitamin D
⚫Teriparatide (synthetic PTH)

26. Treatment of hypercalcemia
⚫Treat the etiology – m/c parathyroid
adenoma
⚫Stop thiazide diuretics
⚫Saline diuresis with furosemide
⚫Inhibit bone resorption
(biphosphonates)
⚫Hemodialysis
⚫Calcitonin as short term measure
⚫Oral phosphates

27. MAGNESIUM
⚫Normal levels 1.5-2.4 m Eq/l
⚫Protein bound(30%), anion
bound(10%) and free(60%)
⚫Calcium channel antagonist and co
factor in ATP powered reactions
⚫Physiological test to detect tissue H-
Mg
⚫Mg is reabsorbed in Henle’s loop and
DCT
⚫RDA : 400mg

29. Hypomagnesemia
⚫40% of hypomagnesemics are
hypokalemic
⚫60% of hypokalemics are
hypomagnesemic
Hypomagnesemia
Slows ATP
production
Na+-K+ ATPase
Loss of intracellular
potassium
Loss of potassium in urine

30. Treatment of
hypomagnesemia
⚫1gm MgSo4 contains 0.1 g of
elemental magnesium
⚫8-12g IV over 24 hours f/b 4-6g IV for
the next three days
⚫Dose to be adjusted in renal
insufficiency
⚫Deep tendon reflexes, RR, Urine
output to be checked while giving Mg
correction

31. Hypermagnesemia
⚫Uncommon in the absence of renal
failure
⚫IV overdose are better tolerated than
oral overdose
⚫Neuromuscular blockade
⚫Calcium channel blockade
⚫ECG changes

33. Treatment of
hypermagnesemia
⚫Stopping Mg in patients with intact
renal function will suffice
⚫Calcium to stabilize the heart
⚫Saline diuresis with loop diuretics
⚫Dialysis for renal failure patients