Potassium is the most important inorganic cation with total
body potassium stores of 50 to 55 mmol/kg. Ninety percent of the
body’s potassium is intracellular, and only 1.4% is in the extracellular
fluid. Only when the intake and discharge of potassium are
in dynamic equilibrium can the serum level remain in the normal
range. Hypokalemia is caused by inadequate intake or loss of
potassium and can occur for many reasons. Abdominal surgery is
characterized by more tissues involved in, severe damage, much
exudation in the surgical field, excessive loss of digestive fluid,
and long fasting times, as well as an inhibition of gastrointestinal
mortality after the surgery