Hyperkalemia

  • Spurious hyper K+ (lab error)
  • Excess ingestion
  • Fasting
  • Drugs (Succinylcholine, B-Blockers, K+ sparing diuretics)
  • Tumor lysis
  • Hyper K+ Periodic Paralysis
  • Acute/Chronic renal failure
  • Adrenal insufficiency
  • Low renin states

EKG changes with high K+

  1. Peaked T waves
  2. Prolonged PR interval
  3. Absent P waves and widened QRS (Sinusoidal wave pattern)
  4. Ventricular arrhythmias

Treatment for hyperkalemia

  • Calcium Gluconate 100 mg/kg
  • Glucose 1g/kg
  • Insulin 0.1 unit/kg
  • Kayexalate
  • Na HCO3 1-2 mEq/kg
  • Albuterol
  • Dialysis

Hypokalemia

Without K+ deficit: alkalosis, B-agonist, familial periodic paralysis, thyrotoxic periodic paralysis, excessive insulin

With K+ deficit: decreased intake, renal losses (hyperaldosteronism, osmotic agents, diuretics), extrarenal losses (GI losses - V/D, NG suction, laxative abuse)

EKG changes with low K+

  1. T wave flattening or inversion
  2. ST depression
  3. Appearance of U wave

Other important changes with low K+:

  • Skeletal Muscle weakness
  • Adynamic ileus

Hypochloremia

With Metabolic alkalosis: vomiting, diuretics, NG suction, steroids

With Hyponatremia: adrenal insuff, edematous states, SIADH, renal failure

Hyperchloremia

With Metabolic acidosis (normal AG): drains, carbonic anhydrase inhibitors, RTA, NH4Cl, diarrhea

Iatrogenic: 3%, 7% NaCl therapy

Hypomagnesemia

Decreased intake: TPN, malnutrition, anorexia

Increased losses

  • GI: malabsorption (small bowel dz, UC, bowel resection, pancreatitis, CF)
  • Renal: tubular d/o (RTA), postrenal transplant, DKA, hypercalciuria, hyperaldosteronism, meds
  • Miscellaneous: epi, B-agnostic, thyrotoxicosis, blood transfusion w/ citrate, burns

Hypermagnesemia

  • Renal failure
  • Iatrogenic administration (antacids, enemas, TPN)
  • Megadose vitamin-mineral supplements
  • Mg infusions (status asthmaticus, eclampsia)

Hypophosphatemia

  • Respiratory alkalosis
  • TPN use (especially premies)
  • Refeeding syndrome
  • Thermal burns
  • DKA
  • Alcohol withdrawal

Hyperphoshatemia

  • Increased intake: phosphate supplements, enemas
  • Decreased renal excretion: acute/chronic renal failure, hypoparathyroidism, heparin, vit D intox
  • Redistribution (extracellular to intracellular): tumor lysis syndrome, rhabdomyolysis, hemolysis, crush injuries, hyperthermia, respiratory acidosis, metabolic acidosis