Lev0phed

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My dad had an anaphylactic reaction to a couple bee stings the other day (he has a known allergy), necessitating a visit to one of the EDs near where their cabin is located. When he got there, his systolic pressure was something like 80 and he was pretty altered. He was give epi, IVFs, etc. and apparently improved pretty rapidly.

Anyway, the er doc (not sure if it was an FM since it's a rural area) wanted to d/c him two hours later because his pressure was back up. I got on the phone and called him, told him that that should be a slam dunk admission for OBS especially in a 70 year old. Suffice it to say, he was reluctant to admit.

I checked the reccs on UpDate in the biphasic anaphylaxis article and it seems to agree with me. Of course my dad had 0 interest in staying in the hospital because hes stubborn and im sure that didnt help.

Curious to know what the standard of care is in this situation. I certainly wouldnt have considered this a BS 24-hour admission.
 

filhodeinferno

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My dad had an anaphylactic reaction to a couple bee stings the other day (he has a known allergy), necessitating a visit to one of the EDs near where their cabin is located. When he got there, his systolic pressure was something like 80 and he was pretty altered. He was give epi, IVFs, etc. and apparently improved pretty rapidly.

Anyway, the er doc (not sure if it was an FM since it's a rural area) wanted to d/c him two hours later because his pressure was back up. I got on the phone and called him, told him that that should be a slam dunk admission for OBS especially in a 70 year old. Suffice it to say, he was reluctant to admit.

I checked the reccs on UpDate in the biphasic anaphylaxis article and it seems to agree with me. Of course my dad had 0 interest in staying in the hospital because hes stubborn and im sure that didnt help.

Curious to know what the standard of care is in this situation. I certainly wouldnt have considered this a BS 24-hour admission.
He probably wouldn't have been admitted where I work. Observe for 4-6 hours then DC if he responded that well and looked that good.
 

EctopicFetus

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He probably wouldn't have been admitted where I work. Observe for 4-6 hours then DC if he responded that well and looked that good.
Agreed. Same where I am. I would obs in the ED and then dc unless multiple other comorbities. UP to date isnt the gold standard. It is there for guidance.

I can assure you those patients dont get admitted at any busy hospital unless they dont get better or have other issues.
 
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fahimaz7

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Biphasic is super rare. It averages 8 hours after initial episode but has been described 48 hours later. I would D.C. him home with an epi pen in hand. I've only admitted 2 in 5 years and both had a biphasic reaction while in the ED during their obs period. Neither had a third dose of epi during their admission.
 

cbrons

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So this is a situation where the E.M. literature and I.M. literature differ in their recommendations. If you look at Tintinelli's it basically says that very few of these patients require admission, even if they were hypotensive or require airway intervention on admission (assuming that these interventions completely ameliorated the problem). If you look at texts like Hospital Medicine or even UpToDate (pretty sure the authors of those articles are immunologists), then they suggest a more cautious approach that includes admitting anyone who was unstable when they arrived in the E.D. for 24-hour admission, regardless of whether or not they're clinically improved compared to their initial presentation.

I actually completely disagree with the EM literature on this one, because ~20% of anaphylactic reactions are biphasic. There is a medscape article which points this out and then goes on to say that too many of these patients are discharged from the E.D. inappropriately. From a medicolegal standpoint, there is very little harm in admitting patients with severe presentations regardless of their status 2-3 hours post-treatment, and few internists would give you hard a time about it IMO.
 

Mad Jack

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My dad had an anaphylactic reaction to a couple bee stings the other day (he has a known allergy), necessitating a visit to one of the EDs near where their cabin is located. When he got there, his systolic pressure was something like 80 and he was pretty altered. He was give epi, IVFs, etc. and apparently improved pretty rapidly.

Anyway, the er doc (not sure if it was an FM since it's a rural area) wanted to d/c him two hours later because his pressure was back up. I got on the phone and called him, told him that that should be a slam dunk admission for OBS especially in a 70 year old. Suffice it to say, he was reluctant to admit.

I checked the reccs on UpDate in the biphasic anaphylaxis article and it seems to agree with me. Of course my dad had 0 interest in staying in the hospital because hes stubborn and im sure that didnt help.

Curious to know what the standard of care is in this situation. I certainly wouldnt have considered this a BS 24-hour admission.
I've seen many anaphylaxis cases with rapid reversal like this (and been one myself) and I've never had one become an admit. Usually it's 4ish hours of obs after symptom resolution, here's an epi pen in case symptoms return and a script for prednisone, see you later.

I don't know if that's standard of care, but it's just what I've been witness to at both a large tertiary care center and a community hospital.
 

filhodeinferno

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So this is a situation where the E.M. literature and I.M. literature differ in their recommendations. If you look at Tintinelli's it basically says that very few of these patients require admission, even if they were hypotensive or require airway intervention on admission (assuming that these interventions completely ameliorated the problem). If you look at texts like Hospital Medicine or even UpToDate (pretty sure the authors of those articles are immunologists), then they suggest a more cautious approach that includes admitting anyone who was unstable when they arrived in the E.D. for 24-hour admission, regardless of whether or not they're clinically improved compared to their initial presentation.

I actually completely disagree with the EM literature on this one, because ~20% of anaphylactic reactions are biphasic. There is a medscape article which points this out and then goes on to say that too many of these patients are discharged from the E.D. inappropriately. From a medicolegal standpoint, there is very little harm in admitting patients with severe presentations regardless of their status 2-3 hours post-treatment, and few internists would give you hard a time about it IMO.
20%?! That seems a bit high....but admittedly I haven't review the numbers on this recently.
 

fahimaz7

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20%?! That seems a bit high....but admittedly I haven't review the numbers on this recently.
"To our knowledge, this is the largest study to date examining ED allergic reactions, anaphylaxis, biphasic reactions, and allergy-related mortality. We identified 2,819 patient encounters during a 5-year period, which composed 0.66% of all ED patients. We applied an objective and reproducible definition for anaphylaxis to each study patient and identified 496 patient encounters with anaphylaxis. Clinically important biphasic reactions, which satisfied the definition for anaphylaxis with recurrent or new signs or symptoms without reexposure to an allergen, were identified through a comprehensive strategy, revealing an incidence of 0.18%. This assists clinicians by demonstrating that few patients with allergic reactions or anaphylaxis have subsequent clinically important biphasic reactions."

Recent annals study. http://www.annemergmed.com/article/S0196-0644(13)01536-9/fulltext
 

GeneralVeers

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Yep D/C home after symptom resolution. I only admit for persistent symptoms after 2 hours or so if not responding well to meds.
 

cbrons

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"To our knowledge, this is the largest study to date examining ED allergic reactions, anaphylaxis, biphasic reactions, and allergy-related mortality. We identified 2,819 patient encounters during a 5-year period, which composed 0.66% of all ED patients. We applied an objective and reproducible definition for anaphylaxis to each study patient and identified 496 patient encounters with anaphylaxis. Clinically important biphasic reactions, which satisfied the definition for anaphylaxis with recurrent or new signs or symptoms without reexposure to an allergen, were identified through a comprehensive strategy, revealing an incidence of 0.18%. This assists clinicians by demonstrating that few patients with allergic reactions or anaphylaxis have subsequent clinically important biphasic reactions."

Recent annals study. http://www.annemergmed.com/article/S0196-0644(13)01536-9/fulltext
That's but one of the studies that looked at this issue. From the UpToDate article:

Estimates of the incidence of biphasic reactions vary from 1 to 23 percent of all anaphylactic reactions. Most studies have been done in emergency departments. Both retrospective and prospective protocols have been employed [13,26]. One study assessed the frequency of "clinically important events" and found that these were rare (0.18 percent), and there were no fatalities [26]. However, severe second reactions occurred more frequently in other studies, and fatalities have been reported [13,16,23].

Other studies have evaluated the incidence of biphasic anaphylaxis in selected clinical settings.

●Biphasic reactions occurred in 10 and 23 percent of cases in two studies of patients receiving immunotherapy, both of which included adults and children [32,33].

●Rates of biphasic anaphylaxis were much lower in a study of children undergoing oral food challenges (1.5 to 2 percent) [10,28]. (See "Oral food challenges for diagnosis and management of food allergies", section on 'Safety'.)


incidence and characteristics of biphasic anaphylaxis: a prospective evaluation of 103 patients.
AU
Ellis AK, Day JH
SO
Ann Allergy Asthma Immunol. 2007;98(1):64.
BACKGROUND Although it is known that anaphylaxis can follow a biphasic course, reports of its incidence are conflicting. Furthermore, little is known about predictors of biphasic reactivity.
OBJECTIVE To describe the incidence and characteristics of biphasic anaphylaxis occurring in a Canadian tertiary care center.
METHODS All patients with emergency department visits and inpatients given a diagnosis of "allergic reaction" or "anaphylaxis" during a 3-year period were evaluated. Patients were contacted within 72 hours to establish symptoms and determine the presence of biphasic reactivity. A full medical record review ensued, and uniphasic and biphasic cases were compared using the Mann-Whitney U test for continuous data and the chi2 and Fisher exact tests for ordinal data.
RESULTS A total of 134 patients with anaphylaxis were identified; complete follow-up was obtained for 103 patients. Twenty patients (19.4%) experienced confirmed biphasic reactivity. Average time to onset of the secondphase was 10 hours (range, 2-38 hours); 8 patients (40.0%) had their second phase occur more than 10 hours after the initial reaction. The clinical presentations and histories of uniphasic and biphasic reactors were similar. Time to resolution of initial symptoms was significantly longer for biphasic reactors (112 vs 133 minutes; P = .03). Differences in management were noted: biphasic reactors received less epinephrine (P = .048) and tended to receive less corticosteroid (P = .06).
CONCLUSIONS Biphasic reactivity occurred with an incidence of 19.4%, consistent with first descriptions. The second-phase onset was 10 hours on average, but it occurred as late as 38 hours. Biphasic anaphylaxis may be related, in part, to undertreatment.
 

fahimaz7

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That's but one of the studies that looked at this issue. From the UpToDate article:

Estimates of the incidence of biphasic reactions vary from 1 to 23 percent of all anaphylactic reactions. Most studies have been done in emergency departments. Both retrospective and prospective protocols have been employed [13,26]. One study assessed the frequency of "clinically important events" and found that these were rare (0.18 percent), and there were no fatalities [26]. However, severe second reactions occurred more frequently in other studies, and fatalities have been reported [13,16,23].

Other studies have evaluated the incidence of biphasic anaphylaxis in selected clinical settings.

●Biphasic reactions occurred in 10 and 23 percent of cases in two studies of patients receiving immunotherapy, both of which included adults and children [32,33].

●Rates of biphasic anaphylaxis were much lower in a study of children undergoing oral food challenges (1.5 to 2 percent) [10,28]. (See "Oral food challenges for diagnosis and management of food allergies", section on 'Safety'.)


incidence and characteristics of biphasic anaphylaxis: a prospective evaluation of 103 patients.
AU
Ellis AK, Day JH
SO
Ann Allergy Asthma Immunol. 2007;98(1):64.
BACKGROUND Although it is known that anaphylaxis can follow a biphasic course, reports of its incidence are conflicting. Furthermore, little is known about predictors of biphasic reactivity.
OBJECTIVE To describe the incidence and characteristics of biphasic anaphylaxis occurring in a Canadian tertiary care center.
METHODS All patients with emergency department visits and inpatients given a diagnosis of "allergic reaction" or "anaphylaxis" during a 3-year period were evaluated. Patients were contacted within 72 hours to establish symptoms and determine the presence of biphasic reactivity. A full medical record review ensued, and uniphasic and biphasic cases were compared using the Mann-Whitney U test for continuous data and the chi2 and Fisher exact tests for ordinal data.
RESULTS A total of 134 patients with anaphylaxis were identified; complete follow-up was obtained for 103 patients. Twenty patients (19.4%) experienced confirmed biphasic reactivity. Average time to onset of the secondphase was 10 hours (range, 2-38 hours); 8 patients (40.0%) had their second phase occur more than 10 hours after the initial reaction. The clinical presentations and histories of uniphasic and biphasic reactors were similar. Time to resolution of initial symptoms was significantly longer for biphasic reactors (112 vs 133 minutes; P = .03). Differences in management were noted: biphasic reactors received less epinephrine (P = .048) and tended to receive less corticosteroid (P = .06).
CONCLUSIONS Biphasic reactivity occurred with an incidence of 19.4%, consistent with first descriptions. The second-phase onset was 10 hours on average, but it occurred as late as 38 hours. Biphasic anaphylaxis may be related, in part, to undertreatment.
Are you EM or IM? Do you admit all of your patients who receive epi? If so, are they observed for 72 hours as biphasic reactions have been described that far out? Even with an advanced degree in immunology I don't keep patients in fear of the biphasic reaction. The treatment is epi and they leave my department with it in hand. If 20% of my populations has a biphasic anaphylactic reaction they certainly don't come back for it. In fact, I've never evaluated an ED patient for a biphasic reaction after being sent home earlier for a presumed uniphasic reaction...
 

southerndoc

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I observe for 2 hours. If they need repeat epi they get admitted. If their vitals are stable, they go to the house with a script for an EpiPen, methylprednisolone, and OTC diphenhydramine/famotidine.

There's no reason to keep an anaphylaxis that doesn't require repeat epinephrine doses except in rare instances. The hypotension is to be expected with anaphylaxis and is easily treated.
 
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Janders

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I keep them 4 hours if they needed epi. Maybe more like 3 if they are with family, have an epi pen, live nearby, appear trustworthy, etc etc....
 

Tenk

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3-4 hours then D.C. assuming 100% resolution and a good means to return if need be.
 

BoardingDoc

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"To our knowledge, this is the largest study to date examining ED allergic reactions, anaphylaxis, biphasic reactions, and allergy-related mortality. We identified 2,819 patient encounters during a 5-year period, which composed 0.66% of all ED patients. We applied an objective and reproducible definition for anaphylaxis to each study patient and identified 496 patient encounters with anaphylaxis. Clinically important biphasic reactions, which satisfied the definition for anaphylaxis with recurrent or new signs or symptoms without reexposure to an allergen, were identified through a comprehensive strategy, revealing an incidence of 0.18%. This assists clinicians by demonstrating that few patients with allergic reactions or anaphylaxis have subsequent clinically important biphasic reactions."

Recent annals study. http://www.annemergmed.com/article/S0196-0644(13)01536-9/fulltext
Thank you. The majority of biphasic reactions I'm aware of are primarily in pediatric patients. If you come in with anaphylaxis, you get epi and improve, you go home. Maybe obs for 2 hours, but honestly if we need to move people and you're doing fine,I am not aware of any good data which state that you shouldn't be the one that's safe to leave
 

TimesNewRoman

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That's but one of the studies that looked at this issue. From the UpToDate article:

Estimates of the incidence of biphasic reactions vary from 1 to 23 percent of all anaphylactic reactions. Most studies have been done in emergency departments. Both retrospective and prospective protocols have been employed [13,26]. One study assessed the frequency of "clinically important events" and found that these were rare (0.18 percent), and there were no fatalities [26]. However, severe second reactions occurred more frequently in other studies, and fatalities have been reported [13,16,23].

Other studies have evaluated the incidence of biphasic anaphylaxis in selected clinical settings.

●Biphasic reactions occurred in 10 and 23 percent of cases in two studies of patients receiving immunotherapy, both of which included adults and children [32,33].

●Rates of biphasic anaphylaxis were much lower in a study of children undergoing oral food challenges (1.5 to 2 percent) [10,28]. (See "Oral food challenges for diagnosis and management of food allergies", section on 'Safety'.)


incidence and characteristics of biphasic anaphylaxis: a prospective evaluation of 103 patients.
AU
Ellis AK, Day JH
SO
Ann Allergy Asthma Immunol. 2007;98(1):64.
BACKGROUND Although it is known that anaphylaxis can follow a biphasic course, reports of its incidence are conflicting. Furthermore, little is known about predictors of biphasic reactivity.
OBJECTIVE To describe the incidence and characteristics of biphasic anaphylaxis occurring in a Canadian tertiary care center.
METHODS All patients with emergency department visits and inpatients given a diagnosis of "allergic reaction" or "anaphylaxis" during a 3-year period were evaluated. Patients were contacted within 72 hours to establish symptoms and determine the presence of biphasic reactivity. A full medical record review ensued, and uniphasic and biphasic cases were compared using the Mann-Whitney U test for continuous data and the chi2 and Fisher exact tests for ordinal data.
RESULTS A total of 134 patients with anaphylaxis were identified; complete follow-up was obtained for 103 patients. Twenty patients (19.4%) experienced confirmed biphasic reactivity. Average time to onset of the secondphase was 10 hours (range, 2-38 hours); 8 patients (40.0%) had their second phase occur more than 10 hours after the initial reaction. The clinical presentations and histories of uniphasic and biphasic reactors were similar. Time to resolution of initial symptoms was significantly longer for biphasic reactors (112 vs 133 minutes; P = .03). Differences in management were noted: biphasic reactors received less epinephrine (P = .048) and tended to receive less corticosteroid (P = .06).
CONCLUSIONS Biphasic reactivity occurred with an incidence of 19.4%, consistent with first descriptions. The second-phase onset was 10 hours on average, but it occurred as late as 38 hours. Biphasic anaphylaxis may be related, in part, to undertreatment.
So you respond to a series of 500 patients in a journal with an impact factor of 4.3 with a series of 103 in a journal with an impact factor of 2.6. Sounds right
 

e30ftw

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D/C 4 hrs post EPI administration unless there are complicating circumstances.
 

filhodeinferno

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"To our knowledge, this is the largest study to date examining ED allergic reactions, anaphylaxis, biphasic reactions, and allergy-related mortality. We identified 2,819 patient encounters during a 5-year period, which composed 0.66% of all ED patients. We applied an objective and reproducible definition for anaphylaxis to each study patient and identified 496 patient encounters with anaphylaxis. Clinically important biphasic reactions, which satisfied the definition for anaphylaxis with recurrent or new signs or symptoms without reexposure to an allergen, were identified through a comprehensive strategy, revealing an incidence of 0.18%. This assists clinicians by demonstrating that few patients with allergic reactions or anaphylaxis have subsequent clinically important biphasic reactions."

Recent annals study. http://www.annemergmed.com/article/S0196-0644(13)01536-9/fulltext
Ah, that makes much more sense. 0.18% sounds more what I'd expect rather than 20%. If it was that high, maybe we'd be admitting them.
 

Rendar5

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I actually completely disagree with the EM literature on this one, because ~20% of anaphylactic reactions are biphasic. There is a medscape article which points this out and then goes on to say that too many of these patients are discharged from the E.D. inappropriately. From a medicolegal standpoint, there is very little harm in admitting patients with severe presentations regardless of their status 2-3 hours post-treatment, and few internists would give you hard a time about it IMO.
20% of those with anaphylaxis do not have have a biphasic reaction. You quoted a pieced literature that also says the same thing. The 20% you mention only applies to immunotherapy agents which is not something commonly seen in the ED.
 

swoopyswoop

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Just wondering, why doesn't your dad already have an Epi pen for his known allergy? Or was it not previously anaphylaxis?
 

Venko

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For me it's a discussion with the pt and family.

If they want to leave and are reasonable and live nearby, I would be fine letting them go.

I would recommend four hours obs in our ED if they are okay with it.

If the family isn't comfortable and want to stay longer, I wouldn't fight.


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TooMuchResearch

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Wasnt previously anaphylaxis.

He required 2 doses in total.
Two doses stacked close together or spaced apart?

If I need more than two (0.3-0.5 mg depending on location) doses, then it's IV epi and admit. Otherwise pretty much everyone goes home, usually about 2 hours after epi if they look good. My biggest concern on discharge is the cost of the epi pen.

Then again, sometimes older people get admitted even if they look good. I wasn't there so it's hard to say. If family is concerned, obs/admit is often reasonable.
 
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