Hypokalemia
                               ===========

þ Some electrocardiographic (ECG) findings associated with hypokalemia include 
    flattened or inverted T waves, a U wave, ST depression and a wide PR 
    interval. Formerly, it was stated that prolongation of the QT interval was a 
    significant electrocardiographic finding. This is now known to be incorrect. 
    Due to prolonged repolarization of ventricular Purkinje fibers, a prominent 
    U wave occurs, that is frequently superimposed upon the T wave and therefore 
    produces the appearance of a prolonged QT interval

þ K+ Replacement
 - Rough equivalents:  0.3 mmol/L = 100 mmol replacement
 - IV K+:
  + 20 mEq over an hour > ^ K+ 0.5 mmol/L
  
þ Hypokalemic Periodic Paralysis
 - Prox > Distal weakness, hyporeflexia
 - insidious onset
 - sudden transcellular shifts
 - Familial HPP
  + Autosomal dominant "channelopathy"
  + Mostly in those of western European ancestry
 - Thyrotoxic HPP
  + most common in Asian males (~ 8% incidence)
 - Responds to IV K+ and beta blockers

þ Admitting:
 - Standard practice is that a K+ of 2.5 or less gets admitted to a monitor.

þ Normal K+ Metabolism
  <E-K.TXT>

þ Hypokalemia and Vomiting
 - Hypokalemia in patients with severe vomiting is generally due to the
   intracellular shifts caused by the metabolic alkalosis which develops from
   vomiting acidic gastric contents.  The hypokalemia is not usually due to
   loss of potassium present in the regurgitated stomach contents.  A
   "contraction alkalosis" caused by dehydration also contributes to the
   hypokalemia. Ref:   Tintinalli 3rd ed. p 71

þ Hypokalemic Metabolic Acidosis
 - Severe diarrhea often causes a loss of both bicarbonate and potassium in
   the stool, which can lead to this condition.
 - Some forms of renal tubular acidosis can cause this condition.
 - Also, during treatment of diabetic ketoacidosis with insulin,
   the intracellular potassium shifts that occur with insulin administration
   can cause a hypokalemia.  As the pH rises, this hypokalemia will worsen
   even further.
 - Refs: Tintinalli 3rd ed. p 71, Rosen 3rd ed. p 2150

þ Role of Mg++ in maintaining hypokalemia
 - If a hypokalemic patient with a normal pH is given a large amount of
   potassium but the hypokalemia persists, concurrent hypomagnesemia can make
   correction of the hypokalemia difficult.  Correction of the hypomagnesemia
   facilitates therapy of the hypokalemia. Ref: Rosen 3rd ed. p 2152