Potassium 

Normal  3.5-5.0 mEq/L

How is K+ transferred?

Active Transport

• Na/K pump
• Insulin

Passive Transport

• Changes in pH
• Cellular Shrinkage

FUNCTIONS

• Transmission of nerve impulses
• Intracellular osmolality
• Enzymatic Reactions
• Acid/Base balance
• Myocardial, skeletal, and smooth muscle contractility

Regulated by

• KIDNEYS
• GI tract
• Skin

Constant state of competition

Hyperkalemia  > 5.0mEq/L (6.5 newborns)

Causes

**Rate of K+ intake or the rate of K+ efflux from ICF to ECF exceeds the sum of losses- (renal and extra-renal)
MAJOR CAUSE – Diminished renal excretion—Renal Failure
Transcellular shifts

Renal Failure
Acidosis
Trauma
Burns
Rhabdomyolysis
Hyperglycemia
Increased intake– IV infusions

Early– irritability, nausea, diarrhea, abdominal cramping
Peaked "T" waves (>6.5 mEq/L)
Diminished cardiac excitablity and Inexcitability(7-8mEq/L)
Prolonged PR dropped P widening QRS
Cardiac standstill (8-10mEq/L)

Insulin and Sodium bicarbonate
Kayexalate enema
Dialysis
IV maintenance

Hypokalemia   <3.5mEq/L

**Reflects a reduction in total body K+ -- renal plus exta-renal K+ losses exceed K+intake
Excessive renal loss
GI loss
Transcellular shifts
Inadequate intake

Diuresis
Osmotic diuresis
Chronic MetabolicAlkalosis
Antibiotics (Amphotericin B, Gentamycin)
Vomiting, diarrhea
Acute alkalosis
Inadaquate intake
Aftermath of trauma, stress
Mineralcorticoid excess

Muscle weakness
"reflex type" paralysis– respiratory failure
"sagging" of ST segment
T wave depression
Elevation of the U wave

IF COMBINED WITH DIGITALIS– SERIOUS ARRYTHMIAS

Athletes
Patients experiencing vomiting diarrhea – especially very young and elderly
Patients receiving large doses of insulin(recovering HHNS, DKA)
On antibiotics
Post trauma

Treat underlying disorders
Replacement therapy
Monitor I/O