Rattibha

1/🧵 Let’s learn about Ace inh-induced angioedema

His lips & tongue swelled up hours after taking a blood pressure med he’d been on 10 years - lisinopril.
📍What’s the treatment?
📍Is it an allergy?
📍What’s a common thought error?
(Pic w Perm - trigger warning tweets 2 & 4)

2/ Angioedema is potentially life-threatening

It’s very scary to see the tongue & lips swelling up so much and the airway compromised.
The patients are watched in the ICU so that intubation and even tracheostomy can occur emergently if required.
What’s the Dz Mechanism?

3/ Is ACE-inh induced Angioedema an allergy?

NO! It’s not an IGE mediated allergic reaction.
💥 Pro Tip:
People can get angioedema from allergies, but they would be very itchy, and my patient was not itching at all.
That's because it's mediated by a buildup of bradykinin.

4/ So why do they nearly always get epinephrine, benadryl & steroids in the ED? @EM_RESUS teach us!

Those agents do NOT ⬇️ swelling when angioedema is due to ACE inh.
There's no medical tx for this other than time & possibly the need for an intervention to maintain the airway.

5/ My patient got those meds & did well, but the treatment & outcome we're unrelated.

Once he’s safely through the swelling, the main thing is to make sure he never gets an ACE inh for BP again. Switch him to other antihypertensives, even angiotensin receptor blockers (ARBs).

6/ Why is the swelling located in the tongue & face?

Bradykinin causes leakage of plasma proteins around the throat & lips, which are super thin & easily expandable.
I’m not aware that bradykinin receptors are clustered there?
Teach me if you know more, please.

7/ The science of this was first worked out by Dr. Nancy Brown & colleagues @VUMC_Medicine, which helped us differentiate between IGE mediated & bradykinin mediated edema.
See reference👇

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8/ Icatibant is an antagonist at bradykinin receptors.
You’d think that this approach would work for this problem, but trials have had poor results.
The mainstay approach is watchful waiting in a monitored setting & prevention of future exposure.

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9/fin
Because 2/3rds of people w heart Dz get ACE inhs, too many die every year from this problem.
Every patient who is on ACE-inh must be taught to seek help immediately if she or he starts noticing swelling.
Time is of the essence. Stay safe!
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