Tuesday, June 28, 2011

Primary Aldosteronism: An Approach

Someone asked in the chatbox for me to elaborate on why the CT scan isn't definitive in the diagnostic evaluation of primary aldosteronism. This is probably too long of an explanation to fit in there, so I thought I'd write a post about it.

Primary aldosteronism implies that the adrenal(s) is autonomously making inappropriate amounts of aldosterone, independent of the usual kidney-mediated renin-angiotensin system. The evaluation is undertaken usually in one of two situations- the discovery of an adrenal incidentaloma, or in the investigation of resistant hypertension.

In these cases, the first step is to document autonomous aldosterone secretion; we do this by means of a morning serum aldosterone and renin activity assuming that interfering drugs are not in the picture. A positive screening test includes an elevated aldosterone level, typically greater than 15 ng/dL, and an elevated aldosterone to renin ratio. Many of us use 15 or even 20:1. If this is positive, we move on to the confirmatory biochemical test of showing nonsuppressed aldosterone levels despite a good amount of salt in the system. This can be done by oral salt loading and measurement of 24-hour urine Sodium (should be greater than 200) with concomitant high urinary aldosterone (more than 12).

Alternatively, one can do the IV Saline suppression test showing a high (greater than 10) serum aldosterone despite 2 liters of Normal Saline.

(diagram pilfered fromNature Clinical Practice Endocrinology & Metabolism 2005)

At this point, you've documented that the patient is making inappropriate amounts of aldosterone and that the problem lies within the adrenal (ie not a case of renal artery stenosis leading to secondary hyperaldosteronism). However, as it turns out there are several subtypes of primary aldosteronism:

The exam-favorite Conn's syndrome or aldosterone-producing adenoma is often quoted.

However there can often also be adrenal hyperplasia which can bilateral.

(will not really mention the rare glucocorticoid remediable aldosteronism).

And so the problem is although you know the patient has the biochemical pathology, you don't know which adrenal is causing it. And without going into too much detail, as it turns out nonfunctioning adrenal adenomas are not uncommon, while adrenal hyperplasia may often not be visible on CT or MRI. And so, even if you see a juicy 2 cm right adrenal adenoma, you won't know if this is the source of the high aldosterone, or if this was just an innocent bystander while it's really microscopic pathology in the LEFT gland that's churning out the hormone and causing the blood pressure problems. And the last thing you want to do is to have your surgeon colleague remove the wrong gland, only to find out post-op that your patient remains hypertensive and hypokalemic.

And so, if you look at many of the guidelines out there, IF a patient is deemed to be a good surgical candidate, then often adrenal vein sampling for aldosterone (often normalized to cortisol, to correct for the dilutional effect of the converging veins) is required to lateralize the lesion. And AVS is a technically challenging procedure that only the most experienced of interventional radiologists can do skillfully.

The good news is, medical treatment with Spironolactone is usually very successful. So for most of my patients I try to direct them in this route, rather than the surgical. Because the truth is, if it's hypertension that they're hoping to cure, with many patients (first degree relative with hypertension, or prolonged history of hypertension etc) even if the surgeon took out the correct adrenal, they will STILL be hypertensive (though improved). There, a longish explanation for a fascinating clinical problem. I'd direct you to the Endocrine Society Clinical Practice Guideline if you wanted more bedtime reading.

7 Comments:

Anonymous Anonymous said...

brilliant

5:42 AM  
Anonymous CWS said...

Thanks.. looking forward to more posting regarding endocrine...

10:45 AM  
Blogger 艾丰 said...

jianbin1214
fitflops shoes
fitflops sale
fitflops sale clearance
fitflops sale
fitflops shoes
michael kors outlet
michael kors outlet
michael kors outlet
tiffany and co
tiffany jewellery
beats by dr dre
beats by dre
oakley sunglasses
oakley sunglasses
ray-ban sunglasses
ray ban sunglasses
hollister uk
lululemon outlet
ugg outlet
ugg boots
ugg boots
rolex watches
mulberry handbags
mulberry bags
mulberry outlet
mulberry sale
mulberry handbags
mulberry handbags
louis vuitton handbags
louis vuitton handbags
toms shoes
omega watches
ferragamo shoes

8:43 PM  
Blogger 艾丰 said...

jianbin1214
fitflops shoes
fitflops sale
fitflops sale clearance
fitflops sale
fitflops shoes
michael kors outlet
michael kors outlet
michael kors outlet
tiffany and co
tiffany jewellery
beats by dr dre
beats by dre
oakley sunglasses
oakley sunglasses
ray-ban sunglasses
ray ban sunglasses
hollister uk
lululemon outlet
ugg outlet
ugg boots
ugg boots
rolex watches
mulberry handbags
mulberry bags
mulberry outlet
mulberry sale
mulberry handbags
mulberry handbags
louis vuitton handbags
louis vuitton handbags
toms shoes
omega watches
ferragamo shoes

8:45 PM  
Blogger 柯云 said...

2016-04-19keyun
abercrombie and fitch
coach outlet clearance
tory burch shoes
michael kors outlet
tiffany rings
polo ralph lauren outlet
cheap toms
louis vuitton handbags
cheap ray ban sunglasses
oakley outlet
hollister clothing
christian louboutin sale
adidas trainers
louis vuitton bags
michael kors bags
michael kors outlet
toms
michael kors outlet clearance
christian louboutin shoes
nfl jerseys
coach outlet store
fitflop shoes
michael kors handbags
concords 11
louis vuitton bags
ralph lauren outlet
gucci handbags
jordan retro 11
kate spade handbags
louis vuitton purses
celine handbags
cheap rolex watches
ray ban outlet
rolex watches
air jordan 4
beats by dr dre
louis vuitton handbags
air jordan shoes
hollister clothing store

3:33 AM  
Blogger Hoai Nguyen said...

chung cư 69B Thuỵ Khuê, chung cu 69B Thuy Khue, chung cư C51 Bộ công an, chung cu C51 Bo cong an, chung cư gold season 47 nguyễn tuân, chung cư gold season, chung cư 47 nguyễn tuân, chung cư vinata tower 289 khuất duy tiến, chung cư vinata towers, chung cư the garden hill, chung cư the garden hill 99 trần bình, chung cư Bắc Hà tây hồ tây, chung cư hải đăng tower, chung cư hải đăng 29 láng hạ, chung cư 29 láng hạ
chung cư Mon city, chung cư Mon city mỹ đình, hd mon city, mon city, dự án mon city, dự án mon city mỹ đình, chung cư mon city, chung cu mon city, chung cư mon city mỹ đình, mon city, hd mon city, chung cư hải đăng city, chung cư hải đăng mỹ đình
chung cư 423 minh khai, chung cư imperia sky garden, chung cu 423 minh khai

4:03 AM  
Blogger Hoai Nguyen said...

Thị trường sôi động với dự án Chung cư vinata tower, nằm trên mặt đường Khuất duy tiến, dự án chung cư vinata towers, chung cư vinata tower 289 khuất duy tiến,
Chung cư the artemis số 3 lê trọng tấn,
Chung cư udic riverside,
Dự án the manor central park khởi công, sắp ra hàng liền kề the manor central park, biệt thự the manor central park. Dự án the manor nguyễn xiển sẽ ra hàng trong năm 2016 này, the manor central park nguyễn xiển hứa hẹn là một siêu dự án cao cấp.
chung cư vinata towers Nếu bạn cần thông tin về dự án chung cư Modern Interior 41 Lê văn lương
chung cư 201 Minh khai Vietracimex
chung cư thanh xuân tower Hiện tại, chúng tôi đang phân phối chung cư tháp doanh nhân, tháp doanh nhân ngay chân cầu Trắng Hà Đông tháp doanh nhân hà đông ra hàng 400 căn hộ chung cư the legend toạ lạc mặt đường Nguyễn Tuân - Nguỵ Như kon Tum chung cư the legend 109 nguyễn tuân hoặc dự án chung cư vietracimex mở bán đợt đầu chung cư thanh xuân tower giá cực sốc chung cư eco green city vẫn còn nhiều căn tầng đẹp chung cu eco green city là một lựa chọn tốt chung cư eco green city nguyễn xiển sắp tới đây chung cu eco green city nguyen xien mở bán tiếp toà CT2 eco green city sở hữu vị trí đắc địa eco green city nguyễn xiển mua ngay dự án eco green city

4:04 AM  

Post a Comment

<< Home