Hyperkalemia

Question: How do I reply to an answer to my Hyperkalemia question? I just posted a question about my husband needing a low potassium diet due to hyperkalemia. Someone was kind enough to answer me but I don't know how to post and answer to a question he/she asked in return. I'm new to this. Please guide me through the process. Thanks, YoungAtHeart

Answer: You cannot answer your own question. But you can add additional information. If you have another e-mail address with yahoo. then you can answer the question under that name.

Question: What is the affect of hyperkalemia and hypokalemia on heart rate? Also tell the mechanism of their affect on heart rate.

Answer: Either one can stop your heart and can go into cardiac arrest

Question: What is the affect of slight hyperkalemia and hypokalemia on heart rate? Also tell the mechanism of their affect on heart rate.

Answer: Doc from India?..........................

Question: Please explain why someone with Hyperkalemia would be prescribed? High doses of Potassium 3x daily and why would a person who has low bloodpressure 90/50 and CHF be prescribed drugs like Coreg, and Imdur, both of which cause reduction in blood pressure?

Answer: Wow, this is not good. Hyperkalemia as you know is high potassium, so I don't know why a doctor would prescribe potassium 3 times per day when they already have a high potassium level. And you are right about Coreg. Coreg is used for people who have high blood pressure. Imdur is used for people who have angina, but one of the precautions with Imdur is not to take it if you have low blood pressure. I am unsure if you are talking about yourself or someone you know, but the physician needs to be questioned regarding this and personally I would find another physician. I know that does not answer your question as to why, but I have no answer as to why this would be done. It does not make any sense as to why these would be prescribed with the information you have given. Best wishes.

Question: Pls help me on HyperKalemia and Insuline glucose treament? I know hyperkalemia is k+ high in blood. We use insuline glucose to move k+ from the blood into the cell: how this works? And based on this treatment, the cell really won't care too much K+ in cellular level- will this cause cellular K+ toxicity? Thank you so much.

Answer: It works because the pump is one of the sodium-potassium pumps, and the intracellular potassium level isn't increased markedly because almost all the total body potassium is intracellular, so you're basically spitting in the ocean.

Question: what is the effect of hypokelamia and hyperkalemia on cell excitability? what is the effect of hypokelamia and hyperkalemia on cell excitability?

Answer: Hyperkalemia will do two things - it will depolarize the cell somewhat, but also, since the conductance of potassium channels is also dependent on extracellular potassium concentration, hyperkalemia increases potassium channel conductance. So, in the hyperkalemic state, the delayed outward potassium current will be greater, decreasing repolarization time, so in a way, it increases excitability by allowing the cell to fire again sooner (which is why it leads to a susceptibility for arrhythmias in the heart). Because the cell is also slightly depolarized, at first, the excitability may also be increased because of this - however, being in a depolarized state also means that more sodium channels will be in the refractory state, which will eventually prevent excitability (which is why potassium is used to stop the heart). Hypokalemia will decrease potassium channel conductance and lengthen repolarization time and the refractory period (when the cell can't fire again), decreasing excitability in that sense.

Question: why do your nerve and muscle cells get abnormally excited in hyperkalemia? I was wondering if someone could explain this simply to me so I understand. a sudden increase in extracellular K+ makes nerve and muscle cells abnormally excitable. Why though? Also what is depolarization. Please help!

Answer: Hemolysis can cause an increase in potassium in the blood. Hemolytic anemia can be genetically passed on or acquired from drugs or toxins. It causes the breakdown of red blood cells and the hemoglobin is then released into the fluid surrounding these cells. Repolarization is the return of membrane potential to negative (normal state) after an action potential changed it to a positive state. Sodium-potassium pumps control the amount of sodium and potassium that enters a cell, which controls the membrane electrical potential by changing the ratio of these negative and positively charged ions. The myocytes (muscle cells) of the heart have these sodium-potassium pumps in their membranes in order to have a resting membrane potential of -90mV. Now if our friend who has hyperkalemia has an abundance of potassium ions outside the cells, the concentration gradient across the membrane declines and causes a decrease in the resting membrane potential, which causes a decrease in the maximum action potential (the last point of depolarization). When the membrane potential becomes less and less negative and reaches -45mV, Calcium channels are stimulated so that calcium is released into the cells and potassium is released out. Then when the calcium channels close, the potassium channels continue to allow K+ to leave in order to restore the negative potential across the membrane. The increase in extracellular K+ of people with hyperkalemia changes the effects of important antiarrhythmic agents (drugs that help keep the heart from pumping too fast) which work with the potassium pumps and the change allows the pumps to release even more K+ from the heart cells in a certain time. The higher concentration of potassium leaving makes the resting potential even more positive and even closer to the threshold potential (the membrane potential it must reach at depolarization for an action potential). Edit: I didn't see you're 'simply' request. Basically the added extracellular K+ changes the membrane potential so that the action potential required for contraction is easier to reach.

Question: How does acidosis cause hyperkalemia? What is the mechanism behind this?

Answer: Well, in general terms it is like this: "Acidic blood plasma, or acidosis, is an occasional cause of hyperkalemia. Acidosis, which occurs in a number of diseases, is defined as an increase in the concentration of hydrogen ions in the bloodstream. In the body's attempt to correct the situation, hydrogen is taken up by muscle cells out of the blood in an exchange mechanism involving the transfer of potassium ions into the bloodstream. This can abnormally elevate the plasma's concentration of potassium ions. When acidosis is the cause of hyperkalemia, treating the patient for acidosis has two benefits: a reversal of both the acidosis and the hyperkalemia." That's pretty general, but it covers the basics. Are you looking into a specific condition?

Question: multivitamins, lots of fruit/veg; is it poss that i could get hyperkalemia,hypercalcemia? I take one centrum, and one 600mg calcium supplement each day along with a balanced diet that includes alot of friuts/veg. I was wondering if it was possible for me to get hyperkalemia or hypercalcemia, or will my kidneys just excrete the excess vitamin/electrolytes?

Answer: Good question. Well your liver and kidneys can put up with a lot, but some things they just cant process. Like for instance too much carrots can turn you yellow, and thiamine acid can turn you reddish, but it would take a lot to do so. Also each person is different so consult your doctor. Bit from my point of view eating healthy is OK, just REALLY mo niter those supplements because accidents happen, and it could really hurt you. Your best bet is just to go talk to a doctor or nutritionist

Question: Hyperkalemia? What is the rationale for giving calcium gluconate to treat hyperkalemia?? How does it treat it, and do you put your patient at risk for hypercalcemia?

Answer: Calcium gluconate acts as a diuretic when a patient is not on diuretics. It aids in treating hyperkalemia without causing hypercalcemia if given at the right dose. This is why when it is given CBC blood test are done 4hrs after giving the medication so adjustments can be made to ensure not to much or to little is being given.