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Hi All,
Physiology question for anyone who would be willing to provide some insight. I was talking with a doc friend over the phone about a case the other day, and, as usual, we got cut off.
He had a patient who was hypokalemic. I was asking about replacing potassium, and he was saying that since K+ is extracellular, simply replacing with more K+ is like "pissing in the wind." As he described it. Then he had to hop off.
It seems the patient was on Lasix and this was the initial cause...
So, I'm wondering, why wouldn't K+ replacement given in OR or ICU for that matter, not correct the problem? If the Sodium/Potassium pump has ATP to do work, whether there is a gradient or not, shouldn't it be able to overcome any gradient and get K+ into the cell so it can do its job? Is Na+ required to be given at the same time as K+? I recall the doc mentioning another molecule to give with K+ but connection was dicey and I don't think it was Na+... Also, I was told that a diet high in Carbs can also cause Hypokalemia, and I'm sure it's an oversimplification, but wouldn't that provide lots of ATP to get K+ where it belongs? (counterintuitive?)
I was doing some website reading and came across this sentence, "Unlike treatment of hyponatremia, potassium replacement is not a matter of calculating a correction based on serum potassium levels, since these are a poor reflection of the overwhelming proportion of potassium that is intracellular." So, now I'm confused, I thought K+ was extracellular... (3 NA+ out for every 2 K+ that go in, NA/K pump, no?) So a lab value of less K, is not really reflective of what's outside the cell, is that it? Because so much is inside the cell...
So, what do you do, in essence in the OR to treat hypokalemia whose cause is unknown to you during a case? Giving K simply won't do it, so I was told, and you cannot exactly get a history and figure out underlying causes (aside from you yourself giving something that you know may very well cause this condition, presumably that med might be stopped...)
Curiously,
D712
Physiology question for anyone who would be willing to provide some insight. I was talking with a doc friend over the phone about a case the other day, and, as usual, we got cut off.
He had a patient who was hypokalemic. I was asking about replacing potassium, and he was saying that since K+ is extracellular, simply replacing with more K+ is like "pissing in the wind." As he described it. Then he had to hop off.
It seems the patient was on Lasix and this was the initial cause...
So, I'm wondering, why wouldn't K+ replacement given in OR or ICU for that matter, not correct the problem? If the Sodium/Potassium pump has ATP to do work, whether there is a gradient or not, shouldn't it be able to overcome any gradient and get K+ into the cell so it can do its job? Is Na+ required to be given at the same time as K+? I recall the doc mentioning another molecule to give with K+ but connection was dicey and I don't think it was Na+... Also, I was told that a diet high in Carbs can also cause Hypokalemia, and I'm sure it's an oversimplification, but wouldn't that provide lots of ATP to get K+ where it belongs? (counterintuitive?)
I was doing some website reading and came across this sentence, "Unlike treatment of hyponatremia, potassium replacement is not a matter of calculating a correction based on serum potassium levels, since these are a poor reflection of the overwhelming proportion of potassium that is intracellular." So, now I'm confused, I thought K+ was extracellular... (3 NA+ out for every 2 K+ that go in, NA/K pump, no?) So a lab value of less K, is not really reflective of what's outside the cell, is that it? Because so much is inside the cell...
So, what do you do, in essence in the OR to treat hypokalemia whose cause is unknown to you during a case? Giving K simply won't do it, so I was told, and you cannot exactly get a history and figure out underlying causes (aside from you yourself giving something that you know may very well cause this condition, presumably that med might be stopped...)
Curiously,
D712