Question

Plasma K+ levels are critical, and the kidney plays a major role in maintaining the level at around 5mM (the extracellular concentration). What would happen to cell membrane potential if: a) the kidney allowed too much K+ loss in the urine? b) too much K+ was lost and a doctor replacing the K+ in an infusion drip in hospital gave too much K+ over a short period of time?

Answer 1

SITUATION a) if too much of potassium is lost causes Hypokalemia

which occurs when serum K+ is less 3.5 meq/l :-

Symptoms of Hypokalemia are :

• Weakness, tiredness, or cramping in arm or leg muscles, sometimes severe enough to cause inability to move arms or legs due to weakness (much like a paralysis)
• Tingling or numbness
• Nausea or vomiting
• Abdominal cramping, bloating
• Constipation
• Palpitations (feeling your heart beat irregularly)
• Passing large amounts of urine or feeling thirsty most of the time
• Fainting due to low blood pressure
• Abnormal psychological behavior: depression, psychosis, delirium, confusion, or hallucinations.

SITUATION 2:- If too much K+ is given by the doctor too quickly, it can cause hyperkalemia which is defined as serum K+ more than 5.5 meq/l

Symptoms of Hyperkalemia are:-

• tiredness or weakness
• a feeling of numbness or tingling
• nausea or vomiting
• trouble breathing
• chest pain
• palpitations or irregular heartbeats

In extreme cases, high potassium can cause paralysis or heart failure. If left untreated, high potassium levels can cause your heart to stop.