HypokalemiaHypokalemiaPotassium is one of the body's major ions.
Nearly 98% of the bodys potassium is intracellular. The ratio of
intracellular to extracellular potassium is important in
determining the cellular membrane potential. Small changes in the
extracellular potassium leel can hae profound effects on the
function of the cardioascular and neuromuscular systems. The !idney
determines potassium homeostasis" and excess potassium is excreted
in the urine. INTRODUCTIONpotassium is necessary for the
maintenance of normal charge difference bet#een intracellular and
extracellular enironments. potassium homeostasis is tightly
regulated by specific ion$exchange pumps %primarily by a cellular"
membrane$bound" sodium$potassium &TP$ase'. (erangements of
potassium regulation often lead to neuromuscular" gastrointestinal"
and cardiac conduction
abnormalities.INTRODUCTIONDefinitionDefinitionHypokalemiaHypokalemia
is defined as a potassium leel is defined as a potassium leel less
than ).* m+,-..less than ).* m+,-..Moderate hypokalemia Moderate
hypokalemia is a serum level of 2.5-3is a serum level of 2.5-3
mEq/L.mEq/L. Severe hypokalemia Severe hypokalemia is defined as a
level less thanis defined as a level less than 2.5 mEq/L. 2.5
mEq/L.The reference range for serum potassium level is 3.5-5The
reference range for serum potassium level is 3.5-5 mEq/L mEq/L
PATHOPHYSIOLOGYPATHOPHYSIOLOGYTotal body deficit of potassiumAcute
potassium depletion potassium shifts from the ECto IC spaceOther
causes chronic inadeuate inta!e"lon#$term diuretic or la%ati&e
use" chronic diarrhea" hypoma#nesemia ' hyperhidrosisdiabetic
!etoacidosis" se&ere GI losses ( &omitin# ) diarrhea"
dialysis" and diuretic therapyAl!alosis ' hypothermiainsulin"
catecholamines*istal +TA ' ,artter syndrome" Periodic hypo!alemic
paralysis"Hyperaldosteronism ' hyperthyroid-Abnormalities of serum
potassium are associated Abnormalities of serum potassium are
associated with well described clinical featureswith well described
clinical features::
! "# le$el! "# le$elClinical featuresClinical features
