Hypoaldosteronism/Hyperaldosteronism Flashcards
What is the primary function of aldosterone?
Aldosterone promotes the reabsorption of sodium and the secretion of potassium in the renal tubule.
How does an excess of aldosterone affect serum sodium and potassium levels?
An increase in the level of aldosterone can decrease the level of sodium excreted in the urine significantly. It will also result in the dramatic loss of potassium into the urine.
How does a lack of aldosterone affect serum sodium and potassium levels?
A lack of aldosterone can result in the loss of as much as 10- 20% of the total body’s sodium content per day. Simultaneously, potassium will be conserved. The total lack of aldosterone secretion will result in death in as little as three days.
What ventilatory concerns should you have when anesthetizing a patient with hyperaldosteronism?
Hyperventilation could worsen the hypokalemia associated with hyperaldosteronism.
What is Conn’s syndrome?
Conn’s syndrome is another name for primary hyperaldosteronism. Primary aldosteronism is characterized by an excess of aldosterone due to a functional tumor.
What conditions are associated with primary hyperaldosteronism?
Hyperaldosteronism may occur with pheochromocytoma, hyperparathyroidism, and acromegaly.
What is secondary hyperaldosteronism?
Secondary hyperaldosteronism occurs when aldosterone levels are elevated as a result of increased renin levels. Renovascular hypertension is a common cause of secondary hyperaldosteronism.
What are the signs and symptoms of hyperaldosteronism?
The symptoms are often nonspecific. Systemic hypertension from sodium retention may cause headaches. Hypokalemia may produce polyuria, skeletal muscle weakness, nocturia, and muscle cramps. It eventually results in a hypokalemic metabolic alkalosis. Hypomagnesemia and abnormal glucose tolerance may also be present.
What signs are suggestive of hyperaldosteronism?
Hypokalemia in the presence of hypertension is suggestive of hyperaldosteronism (if potassium wasting diuretics are not being administered).
How can a diagnosis of hyperaldosteronism be ruled out?
An aldosterone level of 9.5 ng/dL after a saline infusion is used to eliminate hyperaldosteronism as the cause of hypokalemia and hypertension.
How can hyperaldosteronism affect the use of nondepolarizing muscle relaxants?
The hypokalemia associated with hyperaldosteronism can result in skeletal muscle weakness and potentiation of nondepolarizing muscle relaxants.
What is the most common cause of primary hyperaldosteronism?
The most common cause of primary hyperaldosteronism is unilateral adenoma in the adrenal gland. About 25% of these patients, though, may exhibit bilateral adenoma.
What are the cardiac considerations for a patient with hyperaldosteronism?
Patients with hyperaldosteronism have a high incidence of ischemic heart disease. A careful preoperative evaluation and close monitoring during anesthesia should be performed.
How might the presence of hyperaldosteronism affect your choice of volatile anesthetic?
Hyperaldosteronism can result in hypokalemic nephropathy and polyuria. In this scenario, the potentially negative effects of sevoflurane on the kidneys might preclude its use.
Should patients undergoing surgery for excision of an aldosteronoma receive supplementary exogenous corticosteroids?
A patient undergoing surgery for an isolated adenoma of the adrenal gland that is secreting aldosterone probably will not need exogenous corticosteroids. A patient presenting for excision of bilateral aldosteronomas, however, will likely need supplementation with corticosteroids.
