Treatment and evaluation of hypokalemia and hyperkalemia in the neonate.
Review causes of hypokalemia and hyperkalemia; identify ways to evaluate for hypokalemia and hyperkalemia; recommendations for evaluation and treatment of hypokalemia and hyperkalemia.
Electrolyte abnormalities are a recognized problem in the neonatal population that health care providers face on a daily basis; specifically, hypokalemia and hyperkalemia. Knowing how to assess and verify for potassium abnormalities prior to initiating treatment is invaluable. Prior to treating electrolyte abnormalities, it is important to evaluate the causes, which can range from a sampling error to effects of medications to a syndrome. The following is a guideline with recommendations on treatment of hypokalemia and hyperkalemia based on the severity and condition of the neonate.
Hyperkalemia is defined as a serum potassium value >6 mmol/L. Immediate intervention is necessary if cardiac changes are present.
If sample was obtained from heel stick the specimen should be analyzed for hemolysis. If no hemolysis is present and the value is >6.5 mmol/L, a repeat venous or arterial specimen should be sent to the laboratory for analysis. Falsely elevated capillary specimens are commonly due to hemolysis.
In the first 48 hours of life, potassium should be withheld from intravenous fluids until urine output is well established and potassium level is decreasing; this is especially important for extremely low birth weight (ELBW) infants. Check all intravenous fluids to ensure that potassium has not been added to the solution. When potassium is added to fluids, maintenance requirements are 1–2 mEq/kg/day.
If hyperkalemia is present in the very low birth weight (VLBW) or ELBW infant in conjunction with low urine output, this is nonoliguric hyperkalemia. Goal is to promote the movement of potassium from the extracellular fluid into the cells by one of three ways:
Administering IV glucose (2 mL/kg of D10) with insulin (0.05 units/kg), followed by a continuous infusion of insulin (0.1 units/kg/h with 2−4 mL/kg/h of D10).
Recheck K 30–60 minutes after starting infusion. Wean insulin drip as the K drops to <6 mmol/L, since there will be a drift downward after stopping.
Administering IV sodium bicarbonate (1–2 mEq/kg/dose) over 30–60 minutes.
Administering albuterol via nebulization (2.5 mg) or IV (4–5 μg/kg/dose over 20 minutes).
If hyperkalemia is severe and/or life threatening, administer 10% calcium gluconate (0.5–1 mL/kg IV) over 5 minutes.