Compositional Imbalance

Hypokalaemia & Hyperkalaemia

Compositional Imbalance

▪ It does not effect the osmolarity of ECF.

▪ It only causes change in the composition of ECF potassium.

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

Hypokalemia

▪ Serum K concentration of less than 3.5 mEq/L.

Causes:

Decrease Oral intake

Of PotassiumGastrointestinal 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

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

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

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

Broad, progressively flat T waves (sometimes inverted) ST segment depression

Prominent UI wave Renal