Tuesday, 18 October 2011

Dr Doctor - a postural drop of 140!

Really interesting case on the ward at the moment. 80 year old man admitted with TIA type symptoms whenever he stood up. Found to have a postural drop in systolic blood pressure between 90 - 140 mmHg. Just to put that in perspective, postural hypotension is considered to be a drop in systolic BP of more than 15 mmHg. The usual culprit is too many antihypertensive medications.

Trouble with this chap is, his systolic BP usually runs around 200 (normal is around 120). Treatment for postural hypotension (after stopping antihypertensive meds) is fludrocortisone, a potent steroid that acts like aldosterone to increase sodium and water retention. Contraindicated in this chap with such a high systolic BP.

The team is also somewhat baffled by the cause of this phenomenon. Addison's disease is a possibility, but random cortisol measurement was normal, suggesting he doesnt have a steroid deficiency. He doesnt have diabetes, so autonomic neuropathy is unlikely, although there are a few other rare causes of autonomic neuropathy. He doesnt have Parkinson's disease so this cant be multisystem atrophy (a Parkinson's plus syndrome affecting the autonomic nervous system). Maybe he has some sort of baroreceptor problem.

We're also unsure as to why his usual systolic BP is so high, and are considering secondary causes of hypertension. He does have chronic kidney disease (renal artery stenosis or other intrinsic renal disease could cause raised BP). We're awaiting 24 hour catecholamine levels (if raised may indicate a phaeochromocytoma - rare adrenaline secreting tumour). We should check his other hormones for Cushing's, Conn's and acromegaly, and look for coarctation of the aorta.

Oh dear, I seem to have regurgitated a medical textbook.

No comments:

Post a Comment