Normal K+ Metabolism
                        ====================

þ Hyperkalemia:
  <E-HyperK.TXT>

þ Hypokalemia:
  <E-HypoK.TXT>

þ K+ intake/output
 - normal intake:               100 mEq/Day
 - normal stool output:         5-10 mEq/Day
 - normal kidney excretion:     90-95 mEq/Day

þ Normal extracellular fluid K+ concentration
 - 65 mEq/dL

þ Normal K+ homeostasis:
 - ^K+ acutely:
  + causes increased epi which then causes decreased K+ via beta adrenergic
    effects
  + causes increased insulin which then causes decreased K+ independent of the
    effect to decrease glucose
 THEREFORE beta blockers tend to prevent normal handling of a K+ load.
 - ^K+ chronically causes changes in aldosterone which then decrease K+ and
   increase Na+

þ Things that change K+ levels:
 - changes in pH
  + metabolic changes cause more effects than respiratory
  + changes in K+ with change in pH depend on the _anion_ changes as much as
    on the magnitude of the change in H+.
  + acidosis causes more changes in K+ than alkalosis.
  + A change in plasma pH of 0.1 results in an inverse change in
    serum potassium concentration by as much as 0.6 mEq/L.
    [Rund, Barkin, Rosen, et al.  Essentials of Emergency Medicine,
    2nd Ed. p 672.]

þ Effects of Acidosis and Alkalosis on K+ levels:
 - Metabolic Acidosis:  (rough estimate): v pH 0.1 = ^K+ 0.66
 - Respiratory Acidosis:  less change than with metabolic acidosis.
 - Anion effects:
  + Mineral (Inorganic) Acids:  ^^^K+
  + Lactic or Ketoacids:  just ^K+ (organic acids cross cell membranes more
    easily than inorganic acids)