Compositional imbalance

1. Compositional
Imbalance
Hypokalaemia & Hyperkalaemia

2. Compositional Imbalance
▪ It does not effect the osmolarity of ECF.
▪ It only causes change in the composition of ECF potassium.

3. Potassium Regulation
Potassium Regulation depends on:
Aldosterone Catecholamine Insulin Acid-base Balance
• Conservation of Na and Water
• Stabilize the blood pressure
• Excrete Potassium
β2-agonists, move K into cells
(Ventolin)
α-agonists, move K out of cells
(epinephrine)
Insulin moves K into cells Acidosis shift K' out of cells
Alkalosis move K into cell

4. Hypokalemia
▪ Serum K concentration of less than 3.5 mEq/L.
Causes:
Decrease Oral intake
Of Potassium
Gastrointestinal Loss Renal loss
Seriously ill patient with nothing by mouth
for several days
NPO without K supplement added to IV
infusion
Excessive Alcoholism increase K Excretion
by increasing urination

5. Causes
Gastrointestinal Loss
Persistent Vomiting or NG suction
Without fluid replacement
Loss gastric acid HCL
Decrease acid result in alkalosis
Alkalosis shift K into renal tubules
K excretion occur through urine
Decrease serum Potassium
Lower intestinal Tract have large
amount of K
Diarrhea or chronic laxative cause
K excretion
Decrease serum Potassium
Upper GI tract loss Lower GI tract loss

6. Renal loss
Diuretic drugs (thiazides, furosemide)
Renal diseases
Diuretic recovery phase of acute renal failure
Renal tubular acidosis
Diabetic acidosis leading to osmotic diuresis
Healing stage of severe burns Excessive mineralocorticoid effect
Hyperaldosteronism
Cushing's syndrome; corticosteroid therapy
Licorice ingestion (aldosterone-like activity)
Swallowing chewing tobacco (contains large amounts of licorice)
Antibiotics (carbenicillin, aminoglycosides)
Magnesium (Mg**) depletion

7. SIGNS AND SYMPTOMS
CNS and neuromuscular
Early symptoms are vague: fatigue, "not feeling well"
Paresthesias
Diminished deep tendon reflexes
Generalized muscle weakness
Respiratory Weak respiratory muscles, shallow respirations
(advanced) Gastrointestinał
Decreased bowel motility:
anorexia, nausea, vomiting,ileus
Cardiovascular
Postural hypotension
Dysrhythmias (particularly when digitalis or heart dis
ease present) ECG changes