Electrolytes

Table Of Contents
1 Hyponatremia
1.1 Hypervolemic Hypo-Natremia
1.2 Euvolemic Hyponatremia
1.3 HypOvolemic Hypo-Natremia
2 Hyper-Kalemia (K+)
3 HypO-Kalemia
4 Hyper-Magnesimia
5 HypO-Magnesimia
6 Hyperphosphatemia

Hyponatremia

Hypervolemic Hypo-Natremia
  • Causes:
    • CHF
    • Cirrhosis
    • Nephrotic Syndrome
Euvolemic Hyponatremia
  • Causes:
    • Compulsive H2O drinking (Psychogenic polydipsia)
HypOvolemic Hypo-Natremia
  • Causes:
    • Adrenal Insufficiency
    • Diuretics  (urine sodium elevated)
    • GI loss of fluids (vomiting, diarrhea)
    • Renal
    • Skin loss of fluids(Burns, Sweating)
  • Management:
    • Correct the underlying cause and replace it with normal (isotonic) saline. Remember to check serum sodium frequently.

Hyper-Kalemia (K+)

  • Diagnosis:
    • First peaked T-waves occur, then loss of the P-wave, and then the widened QRS complex occurs.
  • Management:
    • Moderate HyperKalemia with no EKG abnormalities:
      • 1 – Insulin and glucose intravenously.
      • 2 – Bicarbonate to shift K+ into the cell when acidosis is the cause of the K+ or there is rhabdomyolysis, hemolysis, or another reason to alkalinize the urine.
      • 3 – Kayexalate (K+-binding resin) is administered orally to remove K+ from the body. This takes several hours.

    • Severe HyperKalemia with EKG abnormalities:
      • 1 – Administer Ca++ gluconate IV to protect the heart.
      • 2 – Follow with insulin and glucose IV.
      • 3 – Conclude with Kayexalate.

    • Bicarbonate MOA to lower K+:
      • When alkalosis pulls H+ out of cells, another cation must go in to maintain electrical neutrality. As H+ ions come out of cells, K+ goes in.

HypO-Kalemia

  • EKG
    • Show “Uwaves,” which have an extra wave after the T-wave indicative of Purkinje fiber repolarization.
  • Management:
    • IV K+ replacement must be slow so as not to cause an arrhythmia with overly rapid administration.
    • Avoid:
    • Glucose-containing fluids in cases of HYPO-K+. They will increase insulin release and worsen hypokalemia.

Hyper-Magnesimia

  • Presentation:
    • muscular weakness and loss of deep tendon reflexes.
  • Management:
    • 1. Restricting intake
    • 2. Saline administration to provoke diuresis
    • 3. Occasionally dialysis

HypO-Magnesimia

  • Presentation:
    • HYPO-Ca++ and cardiac arrhythmias
  • Causes:
    • – Loop diuretics
    • – Alcohol withdrawal, starvation
    • – Drugs: Gentamicin, amphotericin, diuretics, Cisplatin
    • – Parathyroid surgery
    • – Pancreatitis

Hyperphosphatemia