What is Hyperkalemia?
The normal potassium level for a person is from 3.5 to 5.0 milliEquivalents per liter (mEq/L). When a person's potassium goes above 5.0 mEq/L, they are considered to be hyperkalemic. Potassium is especially important in the function of nerves and muscles (including a person's heart).
The most common cause of an increased potassium levels is kidney failure. The kidneys help to get rid of excess potassium in a person's body. When the kidneys fail, the potassium continues to build up and can be fatal if untreated. A few other causes of hyperkalemia are found below:
- Alcohol or drug use which causes rhabdomyolisis, muscle breakdown which releases potassium into the bloodstream
- Overuse of potassium supplements
- Certain types of chemotherapy
- Trauma including severe burns
- Specific blood pressure medications or anti-diuretics
Insulin and Glucose: Insulin is the facilitator that brings glucose into the cells. When this happens, potassium follows the glucose which decreases the serum potassium level. Last night I cared for a patient with a high potassium level of 6.7 mEq/L. The order that the doctor gave me for insulin and Dextrose 50% in water (D50 or IV glucose) was to administer one amp (50 mL) of D50 and 10 units of insulin given IV push.
Albuterol Nebulizer: Albueterol is a beta-2 adrenergic agonist. As such, it promotes the reuptake of potassium on the cellular level. The doctor last night ordered the insulin/glucose combination and the albuterol nebulizer as the first interventions for my patient's high potassium level.
Kayexelate: Kayexelate or sodium polystyrene sulfonate is a laxative which cause potassium to be excreted through the stool. It can be taken either orally (in non-critical hyperkalemic patients) or rectally (as an enema for an emergency hyperkalemic crisis). Most of the absorption occurs in the colon so enemas are the most effective and quick way to begin excretion of potassium from the GI tract.
Dialysis: In hemodialysis, potassium can be quickly removed using the dialysis machine. There is a certain mixture (or bath as the dialysis nurses call it) that is used for blood filtration which removes or adds electrolytes to a patient's body. This is the most invasive, but probably most effective way to remove potassium. A dialysis catheter must be placed prior to HD being performed. Because of this, it is a last resort done after the prior treatments have not worked or if the potassium levels is critically high with no time to wait for the above interventions.
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