Primary aldosteronism (hyperaldosteronism): Clinical sciences

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Introduction0:00–0:30

Primary aldosteronism, also known as primary hyperaldosteronism or Conn syndrome, is a condition in which the adrenal glands produce an excessive amount of aldosterone.
These individuals typically present with hypertension that is refractory to medical management. Now, the most common causes of primary aldosteronism include adrenal adenomas, idiopathic hyperaldosteronism, as well as a genetic condition called familial hyperaldosteronism.Now, if your patient presents with a chief concern suggesting primary aldosteronism, first, you should perform an ABCDE assessment to determine if your patient is unstable or stable.

Unstable patient0:30–1:55

If the patient is unstable, stabilize the airway, breathing, and circulation. Next, obtain IV access and put your patient on continuous vital sign monitoring, including blood pressure, heart rate, and pulse oximetry.
Finally, if needed, don’t forget to provide supplemental oxygen.Now here’s a high-yield fact to keep in mind! A patient with primary aldosteronism can present with a hypertensive crisis, which occurs when the systolic pressure is above 180 or the diastolic pressure is above 120.
Blood pressure this high puts patients at risk for organ damage, such as acute myocardial infarction, acute renal failure, and intracranial hemorrhage.
Moreover, if there’s evidence of end-organ damage, the hypertensive crisis is often referred to as a hypertensive emergency.
On the flip side, the hypertensive crisis in the absence of end-organ damage is sometimes referred to as hypertensive urgency.
In both cases, your patient requires immediate treatment with an IV antihypertensive, such as nitroprusside, with the goal of gradually lowering blood pressure over 24 hours.
This way you are minimizing the risk of rapid drops in perfusion to vital organs and subsequent ischemic injuries.Now that we're done with unstable patients, let’s go back to the ABCDE assessment and discuss the stable ones.

Stable patient1:55–3:02

First, obtain a focused history and physical examination and order a basic metabolic panel or BMP for short. Your patient may report symptoms like headaches, muscle cramps, weakness, polyuria, and polydipsia.
The most important history findings typically include persistent hypertension, often despite the use of several antihypertensive medications; family history of early-onset hypertension, cerebrovascular accident, or primary aldosteronism.
Additionally, some individuals can have a previous imaging study revealing an incidental adrenal mass. On the other hand, the most important physical exam finding is elevated blood pressure, typically above 150/100.
But, if your patient is taking 3 or more antihypertensives, you should consider primary aldosteronism if blood pressure is still over 140/90.
In both cases, lab results might reveal hypernatremia, hypokalemia, and an elevated serum bicarbonate level.At this point, you should order a plasma aldosterone level and plasma renin activity.

Screening3:02–4:15

By calculating the aldosterone to renin activity ratio you can screen your patient for primary aldosteronism. If the ratio is less than 20 to 1, the screening is negative, so consider an alternative diagnosis.However, if the ratio is greater than 20 to 1, you should suspect primary aldosteronism.
To explain why the ratio is high in primary aldosteronism, recall that under physiologic conditions, renin levels increase when the kidneys are hypoperfused.
This can occur in the setting of hypovolemia, or hypotension. Renin then activates the angiotensin pathway, which in turn stimulates the adrenal glands to increase aldosterone secretion, with a net result of increased water reabsorption and an increase in blood pressure.In a healthy individual, we would only expect to see aldosterone levels increase in the setting of increased renin levels, yielding a normal aldosterone-to-renin ratio.
However, in primary aldosteronism, there is an inappropriate increase in aldosterone levels even when renin levels are low, which is why the aldosterone to renin ratio is abnormally high.Now, once you suspect it, you need to determine whether or not the criteria for diagnosis of primary aldosteronism are met.

Criteria for diagnosis4:15–5:36

These include hypertension, hypokalemia, an aldosterone level greater than 20 nanograms per milliliter, and plasma renin activity that is below the lower limit of normal, so below 1.0 ng/mL/hour, or even undetectable.
If any of these criteria are not met, order confirmatory testing. Confirmatory testing might include an oral sodium loading test, IV saline infusion test, fludrocortisone suppression test, or captopril challenge test.
The oral sodium loading test and IV saline infusion test consist of giving a load of sodium chloride, either orally or intravenously, and then assessing the urinary aldosterone excretion.
On the other hand, for the fludrocortisone suppression test, patients are given fludrocortisone together with sodium chloride loading for 4 days, after which urinary aldosterone excretion is measured.
Lastly, for the captopril challenge test, captopril is administered to the patient, and then the serum aldosterone levels are measured.If the results of confirmatory testing are negative, consider an alternative diagnosis.
But if the results of confirmatory testing are positive, you can confirm the diagnosis of primary aldosteronism. Now, let’s go back to the criteria for diagnosis of primary aldosteronism.

Adrenal adenoma5:36–6:28

If your patient meets all the criteria, you can confirm the diagnosis of primary aldosteronism without additional confirmatory testing.
Once you confirm the diagnosis, your next step is to order an adrenal CT scan. If the CT scan reveals a well-demarcated round or oval adrenal mass, you should suspect an adrenal adenoma.
In this case, consult the surgery team for further management and possible adrenalectomy.Adrenal vein sampling, will help distinguish between unilateral adenoma and bilateral hyperplasia.
A unilateral adenoma is associated with a marked increase in plasma aldosterone concentration on the side of the tumor, whereas patients with bilateral hyperplasia present little difference between the two sides.Now, if the CT scan reveals no adrenal mass, suspect familial hyperaldosteronism.

Idiopathic hyperaldosteronism6:28–6:59

If that’s the case, go through your patient's family history and ask specifically about hyperaldosteronism, early-onset hypertension, or cerebrovascular accident at a young age.
If there’s no family history suggesting familial hyperaldosteronism, diagnose idiopathic hyperaldosteronism and begin treatment with a mineralocorticoid antagonist, such as spironolactone or eplerenone.However, if the family history is suggestive of familial hyperaldosteronism, perform genetic testing to rule out or confirm the diagnosis.

Familial hyperaldosteronism6:59–7:44

If the testing is negative, diagnose idiopathic hyperaldosteronism and again, initiate treatment with a mineralocorticoid antagonist.
However, if the testing is positive, diagnose familial hyperaldosteronism, which can be further classified as type 1, 2, or 3.
Individuals with type 1 are treated with glucocorticoids, which can suppress elevated aldosterone levels. On the other hand, patients with types 2 and 3 are not responsive to this type of treatment, so you should consider mineralocorticoid receptor antagonists, or even surgical consultation for adrenalectomy.Alright, as a quick recap… If you suspect primary aldosteronism, calculate the plasma aldosterone-to-renin activity level ratio.

Review7:44–8:49

If the ratio is less than 20 to 1, consider an alternative diagnosis; but if it’s greater than 20 to 1, suspect primary aldosteronism.
Next, check whether your patient meets the criteria for primary aldosteronism. If any of the criteria are not met, use confirmatory testing to confirm or rule out the diagnosis.
On the flip side, if the patient meets all criteria, diagnose primary aldosteronism, and order an adrenal CT scan. If the CT scan reveals an adrenal mass, suspect an adrenal adenoma and consult the surgical team.
However, if the CT scan reveals no adrenal mass, review the family history. If the family history is not suggestive of familial hyperaldosteronism, diagnose idiopathic hyperaldosteronism.
But, if the family history is highly suggestive of familial hyperaldosteronism, order genetic testing to confirm or rule out the
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