Potassium-related cardiac arrhythmias and their treatment.

Severe abnormalities of potassium balance constitute medical emergencies. Symptoms of hypokalemia are vague between 3.5 and 3.0 mEq/liter. Clinical problems can occur with the plasma potassium value lower than 2.7 mEq/liter. Hypokalemia and digitalis glycosides share electrophysiologic actions. Hypokalemia is both synergistic and potentiating for digitalis. In the presence of a normal amount of digitalis, toxicity may be prompted by coexisting hypokalemia. Hyperkalemia does not threaten life until plasma potassium values are greater than 7.0 mEq/liter. The immediate suspicion and recognition of hypokalemia or hyperkalemia in various clinical situations is imperative. Once suspected, confirmation of the diagnosis should follow immediately. Probably the single most useful diagnostic aid is the electrocardiogram, especially in critical situations with hyperkalemia. Prompt intravenous infusion of a calcium preparation, sodium bicarbonate, glucose, and insulin will provide rapid relief from serious hyperkalemia. The appropriate administration of these readily available drugs may obviate an otherwise critical situation.