A week ago my diabetic wife went to the ER for an infected foot. They put her on an IV with an antibiotic and all went well. They then plugged in a different IV and immediately she went into what was obviously anaphylactic shock. They shooed the kids out of the room but I stayed, making myself very small in a corner, because it was my duty to be present. I held my tongue, except for a suggestion that the IV may have been preserved with a sulfite of some sort, to which she is very allergic. They checked; it wasn’t.
A nurse announced that she had gotten some Benadryl in, and I meekly asked, “What about epinephrine?” It was like they had forgotten the first thing you punch into someone in that condition, but they pumped two loads into her in the next couple minutes.
So, here I am, a civilian, though one with a family and personal history of messy allergies, wondering WTF? Is it part of the procedure to put in the Benadryl first then wait a few minutes for the epi?
Aftermath: Her ribs still hurt from the CPR, the foot infection is superficial, her foot hurts because she broke it in several places trying to get into daughter’s car a month ago (the EMTs had to come and help her up, but she wouldn’t let them take her to have someone look at it because she’s a terrible patient), and she’s still in the hospital for reasons I can’t fathom because she’s a terrible communicator, though one reason is that she’s now on Medicare, something they set up the last time she was in after calling me and asking if she had other insurance.
“Nope.”
“But this only pays $400/day.”
“We had better coverage under Obamacare, but now my company offers this junk.”
My mom got IV Benadryl when she had anaphylaxis during a blood transfusion (she was allergic to the preservative in the blood product) four or five years ago, and the same thing happened a few years earlier when a coworker accidentally gave her advil that they thought was Tylenol. Seems like they use Benadryl when you’re still breathing?
During my hospital stay, I had a reaction to a chocolate and almond bar (never had one before or since). I only got as far as severe itching by the time(just a few minutes) I got a shot of Benadryl followed by two pills of same.
Epinephrine is the medicine that makes the most difference in severe allergic reactions. Benadryl, ranitidine and steroids are often added, sometimes Ventolin. If you are intubating or need other pressors things are serious.
For many allergic reactions to IV medicine, usually a rash going down the arm, Benadryl and steroids are sufficient. Epinephrine is better if the reaction is severe, which may involve drop in blood pressure, shortness of breath, facial or tongue swelling, vomiting and/or wheezing.
If they were doing CPR because of this, in a diabetic, a number of other things could have been going on, many things can cause shock aside from anaphylaxis. It is also possible that there is a protocol that permits the nurse to give Benadryl but the doctor needs to order or push the epinephrine. But in general terms, you are right, if it was anaphylactic shock.
It’s not my area of specialty, but as I understand it, a common protocol is to give Benadryl first, monitor closely, and then give Epi if the symptoms don’t resolve and/or if they get worse (like if their oxygen level goes down, and turning the oxygen in their mask up doesn’t help.) Benadryl is longer acting, I believe the reasoning goes, and if it does the job alone, there’s no reason to submit someone to the pain and side effects of Epi.
HOWEVER, this is not universal, and not without its detractors. There are also health care professionals that feel you should do Epi first, that it’s safe enough in trained hands and carefully dosed, and that the longer onset of Benadryl isn’t worth mucking around with.
So it’s really up to hospital protocol and/or the professional judgement of the practitioner who has assessed the patient.
Benadryl attacks the cause of anaphylaxis, and is a very safe medication. Epinephrine goes after some of the symptoms, and is more difficult and dangerous to use.
Uncontrolled high blood pressure can be a factor in whether Epiniphrine is a first choice, especially when there’s already an IV in place and diphenhydramine can be given IV (very fast and effective). Go the safer route with diphenhydramine first and patient is able to breathe, or give epinephrine first and risk a stroke if the other may have worked but a minute slower…
You and WhyNot are better qualified than I am, for sure! I too would have thought epi first since it’s so fast acting (of course, I have no clue how quickly IV Benadryl works).
I’m curious about CPR / anaphylaxis: I have this image that anaphylaxis (dayum, that’s a tricky word to type, trips up my fingers) causes immediate breathing distress and the heart doesn’t stop… at least not right away, and restarting the heart won’t help if the airway isn’t open. Am I mistaken?
We’ve been able to avoid anaphylaxis here fortunately; nobody has severe allergies to anything except my son to peanuts, and even his is “mild” enough that the last time he got some by mistake he just felt nauseous for a while and then upchucked.
Dropzone - scary stuff; I’m glad they stabilized her quickly. Any idea what DID cause the reaction? was it a different antibiotic? different batch of same antibiotic? (as in, one batch was bad). And, can you get the doctors to talk to YOU, since it sounds like you’re getting garbled third-hand info from your wife? I’d have thought that unless she requires ongoing IV antibiotics, she’d be stable enough to come home unless something else has been going on.
Also on the sulfites, for my own edification: I’ve reacted to sulfites to foods, but have taken Tylenol 3 tablets with no problem. Do you have any clue whether sulfites in IV meds cause issues? Has your wife reacted to that? I always inform doctors, but when I was in labor with my son and begging for pain relief the first thing they tried to give me was sulfite-preserved. NDFH* tried arguing with me: “What will it do to you?” “I’m not sure and I don’t thing NOW is the time to find out!” (one of many reasons I regret only hitting her once**)
Nazi Doctor From Hell
** No, I don’t routinely assault medical personnel. But she kept jamming her fingers into my solar plexus without warning or explanation. The third time she did it I smacked her hand away. I claim self defense. Sadly I was in no position (literally) to smack the idiot anesthesiologist who had me screaming in agony from a botched epidural. Nor was the doctor in reach when she revealed she’d lied to me to get me to come to the hospital earlier than I needed to.
Just to echo what other experts have said: Benadryl IV if they’re trying to die from an anaphylactic reaction, epinephrine if they’re actually seeming to be succeeding at it.
I used the latter on a guy I watched become a pulseless non-breather as we got the IV line in. His BP vanished, and rather than shoot Benadryl, I pushed epi. He came back quick, but came back with a terrible headache.
Your medical librarian has to chime in with this caveat - if you are out of the hospital, the recommendations are different IF you have access to injectable epinephrine and you’ve encountered a known allergen. While there’s still some professional debate (if the person is asymptomatic), there’s no question that using your EpiPen/equivalent is generally safe. Oral Benadryl is great stuff, but use your EpiPen if you just realized that you ate the forbidden peanut http://www.aaaai.org/ask-the-expert/when-epinephrine-injection
At recent conferences like Resuscitation, they emphasize early epinephrine for several reasons, but the best is it works a lot more effectively than antihistamines like Benadryl.
It is not uncommon for diabetics to get severe foot infections, even to need amputations. They are at risk for septic shock, severe dehydration and coma states due to high blood sugar. Blood pressure can drop in severe anaphylaxis but if CPR was given, I would likely give epinephrine but cardiogenic and hypovolemic shock must also be considered, and probably treated. Anaphylactic shock is difficult for experts to diagnose. I know Dropzone to be very intelligent but unless the patient recovered very quickly after getting epinephrine the situation may be more complex. As I said, you’d have to see it.
I would recommend epinephrine or EpiPen use if there is severe vomiting, low blood pressure, wheezing or swelling of the neck, lower face or tongue. Usually there is a rash as well, which by itself does not usually need epinephrine but Benadryl would be a reasonable start. Known exposure to an allergen in the absence of symptoms would not usually require EpiPen but close monitoring, though this might depend on what happened in previous exposures (ICU, intubation).
Actually, in a wilderness setting the rule I’ve been taught is push Benedryl ASAP as long as the person can swallow pills (or use liquid Benedryl). If they get so bad that their throat is closing up give them the Epi and then push more Benedryl. No one is coming to help you for a few hours and I only carry two Epi-pens. My plan is to only use them when they are critical since they only last a few minutes and only treat symptoms. The Benedryl will fight the allergic reaction and the Epi is there so I can get more Benedryl in my system.
For me it’s bee stings. For the most part I can weather a sting without anaphalaxis but if I go over the edge I want to save the Epi for when it’s most needed.
Strictly speaking, Mama Zappa, anaphylaxis does not always cause wheezing or breathing difficulty. CPR is used when the heart is not pumping blood to the body. The blood needs to be oxygenated to be useful, so the airway may need to be opened. The patient may require intubation to protect or secure the airway. The patient may require oxygen, temporary airway measures or be breathing spontaneously. There are many heart arrhythmias, so this needs to be investigated using ECG and, ideally, a quick ultrasound.
Benadryl (dipenhydramine) is used to stop the body’s response to the allergen, thereby allowing the downstream symptoms to stop developing / worsening.
Epinephrine is used to hit the pause button on the symptoms that are already happening. It doesn’t actually reverse the process (or not much - I guess it brings up BP and heart rate), just puts it on hold.
So if you use epi, you have to be doing something else (Benadryl, steroids, whatever) otherwise it just means you’ll die in 15 minutes instead of right now.
It’s more complicated, but you are partially right.
Benadryl is an antihistamine. Histamines are chemicals produced by mast cells, which help the body heal wounds, protect the brain and fight pathogens. However, they can also cause inflammation and allergic reactions. Benadryl stops mast cell degranulation, so stops mild allergies from getting worse, like you say. Ranitidine (Zantac) is a different class (H2) of antihistamine, and is usually added.
More severe allergies involve immunochemicals called complements. These can embiggen blood vessels, dropping blood pressure, make skin red and itchy, cause spasm of the windpipe, etc. Epinephrine is a strong vasopressor which narrows blood vessels, relaxes breathing muscles, makes the heart beat stronger and faster, and counteracts a wider range of immunochemicals, which is why it is first line for a severe allergic reaction.
If you need to give epi, it is far stronger and more effective than steroids and Benadryl. In a hospital, pulse and blood pressure would be monitored. A second dose of epinephrine may need to be given if allergic symptoms worsen or return, though this is actually much less common than traditionally taught. Most of the deaths from anaphylaxis (incidence usually reported as 0.3%) are since epinephrine was not given, due to misdiagnosis or undertreatment.
