Describe the pathophysiology of hypokalemia and clinical manifestations.© BrainMass Inc. brainmass.com December 24, 2021, 11:03 pm ad1c9bdddf
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Condition: lower than normal amount of potassium in the blood
Potassium is needed for cells, especially nerve and muscle cells, to function properly. You get potassium through food. The kidneys remove excess potassium in the urine to keep a proper balance of the mineral in the body. In hypokalemia, the level of of potassium drops due to various reasons such as poor diet or eating disorders, diarrhea/vomitting, disease, low magnesium, and sweating.
Potassium gradients between the intracellular and extracellular space is essential for nerve function; in particular, potassium is needed to repolarize the cell membrane to a resting state after an action potential has passed. Lower potassium levels in the extracellular space will cause hyperpolarization of the resting membrane potential. As a result, a greater than normal stimulus is required for depolarization of the membrane in order to initiate an action potential.
In the heart, hypokalemia causes hyperpolarization in the myocytes' resting membrane potential. The more negative membrane potentials in the atrium may cause arrhythmias because of more complete recovery from sodium-channel inactivation, making the triggering of an action potential more likely. In addition, the reduced extracellular potassium inhibits the activity of the IKr potassium current and delays ventricular repolarization. This delayed repolarization may promote irregular heartbeats.
Clinical Manifestation include:
Abnormal heart rhythms
Muscle weakness or spasms
Paralysis (which can include the lungs)