Final answer:
The late signs and symptoms of hyperkalemia include serious cardiac and neurological effects such as arrhythmias, mental confusion, muscle weakness, numbness, and potentially paralysis. Hyperkalemia is often a result of decreased potassium excretion due to renal failure, dehydration, or Addison's disease, causing dangerous elevation of potassium levels in the blood.
Step-by-step explanation:
The late signs and symptoms of hyperkalemia, an elevated level of potassium in the blood, may include serious cardiac and neurological effects. The cardiac symptoms are of particular concern as hyperkalemia can cause dangerous heart rhythms, including arrhythmias that can lead to cardiac arrest. Patients with late-stage hyperkalemia might experience mental confusion, muscle weakness (including weakened respiratory muscles), numbness, and in severe cases, paralysis. It's important to note that these symptoms are related to elevated plasma potassium levels rather than increased intracellular potassium.
Several conditions can cause hyperkalemia, such as renal failure, severe dehydration, and Addison's disease. These conditions lead to decreased excretion of potassium by the kidneys, causing an accumulation in the blood. This excess potassium in the extracellular fluid (ECF) results in a partial depolarization of cell membranes, which can impede the ability of the cells to repolarize normally after an action potential. This is especially critical in cardiac cells, as it can prevent the heart from relaxing after a contraction.
Potassium accumulation due to hyperkalemia is often accompanied by other metabolic disturbances such as metabolic acidosis, which can further increase the severity of the symptoms. Chronic kidney disease, a common cause of hyperkalemia, can exacerbate cardiovascular complications.