Anaphylaxis: Difference between revisions
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==Background== | ==Background== | ||
==Clinical Features== | ==Clinical Features== | ||
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*Cardiovascular symptoms (35%) | *Cardiovascular symptoms (35%) | ||
**[[Hypotension]] | **[[Hypotension]] | ||
===Expected Course=== | |||
====Uniphasic (80-90%)==== | |||
*Symptoms peak within 30 minutes to 1 hour after onset, resolve within 30 minutes to 1 hour of receiving treatment<ref>Ewan PW. '''ABC of allergies – Anaphylaxis,''' ''BMJ'' 1998; 316: 1442-1445 </ref> | |||
====Biphasic (10-20%)==== | |||
''Biphasic reactions are rare and can occur anywhere from 10 minutes up to six days after an initial reaction.''<ref> Milne K. Biphasic Allergic Reactions: Observation, Treatment Guidelines http://www.acepnow.com/article/biphasic-allergic-reactions-observation-treatment-guidelines/</ref> | |||
*Uniphasic response, followed by asymptomatic period of hour or more, then return of symptoms | |||
*The second phase does not necessarily resemble the first! | |||
*More likely with a severe initial presentation, hypotension, and recurrent epinephrine dosing requirements in the emergency department<ref>Ellis AK, Day JH: Incidence and characteristics of biphasic anaphylaxis: A prospective evaluation of 103 patients. Ann Allergy Asthma Immunology. 2007; 98:64-69</ref> | |||
*Little evidence to support the use of discharge steroids to prevent a biphasic reaction | |||
*0.4% of patients with anaphylaxis had a rebound event while in the ED<ref name="biphasic"/> | |||
==Differential Diagnosis== | ==Differential Diagnosis== | ||
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{{Shock DDX}} | {{Shock DDX}} | ||
==Diagnosis== | |||
Anaphylaxis is highly likely when ANY ONE of the following criteria is fulfilled<ref>Brown SGA, Mullins RJ and Gold MS. '''Anaphylaxis: diagnosis and management,''' ''MJA'' 2006; 185: 283–289 </ref><ref>Lieberman P et al. '''The diagnosis and management of anaphyalxis: An updated practice parameter,''' ''J Allergy Clin Immunol'' 2005;115;3:S483-S523 </ref> | |||
===Criterion 1 (90% of patients)=== | |||
*Acute onset of an illness involving the skin, mucosal tissue, or both AND at least one of the following: | |||
**Respiratory Compromise | |||
**Reduced blood pressure or associated symptoms ([[Syncope]], [[Dizziness]]) | |||
===Criterion 2 (10-20% of pts)=== | |||
*TWO OR MORE of the following that that occur rapidly after exposure to a LIKELY allergen for that patient | |||
**Involvement of the skin-mucosal tissue (hives, swollen lips-tongue-uvula) | |||
**Respiratory compromise | |||
**[[Reduced BP|Hypotension]] or associated symptoms | |||
**Persistent gastrointestinal symptoms: ([[Vomiting|vomiting]], [[Diarrhea|diarrhea]], crampy [[Abd Pain|abdominal pain]]) | |||
===Criterion 3=== | |||
*[[Reduced BP|Hypotension]] after exposure to a KNOWN allergy for that patient (minutes to hours): | |||
**Adults: systolic blood pressure (SBP) <90 mmHg or >30% reduction from baseline | |||
**Pediatrics | |||
***1 month - 1 year: SBP <70 mmHg | |||
***1 year - 10 years: SBP <(70 mmHg + [2 x age]) | |||
***11 years - 17 years: SBP <90 mmHg | |||
==Management== | ==Management== |
Revision as of 06:40, 29 August 2015
Background
Clinical Features
- Cutaneous symptoms (90%)
- Respiratory symptoms (70%)
- Gastrointestinal symptoms (40%)
- Cardiovascular symptoms (35%)
Expected Course
Uniphasic (80-90%)
- Symptoms peak within 30 minutes to 1 hour after onset, resolve within 30 minutes to 1 hour of receiving treatment[1]
Biphasic (10-20%)
Biphasic reactions are rare and can occur anywhere from 10 minutes up to six days after an initial reaction.[2]
- Uniphasic response, followed by asymptomatic period of hour or more, then return of symptoms
- The second phase does not necessarily resemble the first!
- More likely with a severe initial presentation, hypotension, and recurrent epinephrine dosing requirements in the emergency department[3]
- Little evidence to support the use of discharge steroids to prevent a biphasic reaction
- 0.4% of patients with anaphylaxis had a rebound event while in the ED[4]
Differential Diagnosis
Acute allergic reaction
- Allergic reaction/urticaria
- Anaphylaxis
- Angioedema
- Anxiety attack
- Asthma exacerbation
- Carcinoid syndrome
- Cold urticaria
- Contrast induced allergic reaction
- Scombroid
- Shock
- Transfusion reaction
Shock
- Cardiogenic
- Acute valvular Regurgitation/VSD
- CHF
- Dysrhythmia
- ACS
- Myocardial Contusion
- Myocarditis
- Drug toxicity (e.g. beta blocker, CCB, or bupropion OD)
- Obstructive
- Distributive
- Hypovolemic
- Severe dehydration
- Hemorrhagic shock (traumatic and non-traumatic)
Diagnosis
Anaphylaxis is highly likely when ANY ONE of the following criteria is fulfilled[5][6]
Criterion 1 (90% of patients)
- Acute onset of an illness involving the skin, mucosal tissue, or both AND at least one of the following:
Criterion 2 (10-20% of pts)
- TWO OR MORE of the following that that occur rapidly after exposure to a LIKELY allergen for that patient
- Involvement of the skin-mucosal tissue (hives, swollen lips-tongue-uvula)
- Respiratory compromise
- Hypotension or associated symptoms
- Persistent gastrointestinal symptoms: (vomiting, diarrhea, crampy abdominal pain)
Criterion 3
- Hypotension after exposure to a KNOWN allergy for that patient (minutes to hours):
- Adults: systolic blood pressure (SBP) <90 mmHg or >30% reduction from baseline
- Pediatrics
- 1 month - 1 year: SBP <70 mmHg
- 1 year - 10 years: SBP <(70 mmHg + [2 x age])
- 11 years - 17 years: SBP <90 mmHg
Management
- Epinephrine
- 1:1000 IM 0.3 - 0.5mg (0.3 - 0.5mL) every 5 - 15 minutes[7][8]
- Give as soon as possible
- Always IM initially [9]
- If response to IM is inadequate: give epinephrine infusion 1:10,000 2 - 10 µg/min
- How to make a quick epi drip: Take your code-cart epi (it doesn't matter if it's 1:1,000 or 1:10,000) and inject 1mg into a liter bag of NS. Final concentration is 1mcg/ml. Run at 1cc/min and titrate to effect.
- Pediatric: Epinephrine 1:1000 0.01 mg/kg (max 0.5mg) IM every 5 to 15 minutes
- IV infusion: 0.05 - 1 mcg/kg/min
- 1:1000 IM 0.3 - 0.5mg (0.3 - 0.5mL) every 5 - 15 minutes[7][8]
- Supplemental oxygen
- Consider endotracheal intubation if airway edema present
- Normal saline bolus
- If unresponsive to epinephrine assume distributive shock and give 1 - 2 liters of normal saline
- Also consider
- Albuterol
- for bronchospasm resistant to IM epinephrine
- Antihistamines (for symptom control AFTER hemodynamically stable)
- Diphenhydramine: 25 to 50 mg IV
- Ranitidine: 50 mg IV (has been found to improve urticaria but not angioedema at 2 hours[10])
- Glucocorticoid
- MAY blunt biphasic reaction although little evidence to support usage[11]
- Methylprednisolone: 125 mg IV (2mg/kg in children)
- Dexamethasone: 10mg IV or PO (0.6mg/kg in children)
- Glucagon
- 1 - 5mg IV over 5 minutes followed by infusion of 5 - 15 µg/min[12]
- If taking beta-blocker AND unresponsive to epinephrine
- Consider adding additional pressor support if persistent hypotension present
- Albuterol
Disposition
Admit
- Severe and moderate presentations especially if symptoms did not respond promptly to epinephrine or required repeat dosing
Discharge
- Symptom-free for at least 4 hours and mild initial presentation
- Send home with an epinephrine autoinjector! (Epi-Pen)
- Up to 6% of the people with anaphylaxis have a repeat ED visit for anaphylaxis within 7 days[4]
See Also
References
- ↑ Ewan PW. ABC of allergies – Anaphylaxis, BMJ 1998; 316: 1442-1445
- ↑ Milne K. Biphasic Allergic Reactions: Observation, Treatment Guidelines http://www.acepnow.com/article/biphasic-allergic-reactions-observation-treatment-guidelines/
- ↑ Ellis AK, Day JH: Incidence and characteristics of biphasic anaphylaxis: A prospective evaluation of 103 patients. Ann Allergy Asthma Immunology. 2007; 98:64-69
- ↑ 4.0 4.1 Grunau BE et al. Incidence of Clinically Important Biphasic Reactions in Emergency Department Patients With Allergic Reactions or Anaphylaxis. Ann Emerg Med. 2013 Nov 13
- ↑ Brown SGA, Mullins RJ and Gold MS. Anaphylaxis: diagnosis and management, MJA 2006; 185: 283–289
- ↑ Lieberman P et al. The diagnosis and management of anaphyalxis: An updated practice parameter, J Allergy Clin Immunol 2005;115;3:S483-S523
- ↑ Dhami S. et al. Management of anaphylaxis: a systematic review. Allergy. 69 (2014) 168–175. http://onlinelibrary.wiley.com/store/10.1111/all.12318/asset/all12318.pdf?v=1&t=hrspdbpk&s=8067bfd5903c7ffebf4a274f062a71633ebe0507
- ↑ Sheikh A, Shehata YA, Brown SGA, Simons FER. Adrenaline (epinephrine) for the treatment of anaphylaxis with and without shock. Cochrane Database of Systematic Reviews 2008, Issue 4. Art. No.: CD006312. DOI:10.1002/14651858.CD006312.pub2
- ↑ Simons FER, Gu X, Simons KJ. Epinephrine absorption in adults: Intramuscular versus subcutaneous injection, J Allergy Clin Immunol 2001;108:871-3
- ↑ Lin, RY et al. Improved Outcomes in Patients With Acute Allergic Syndromes Who Are Treated With Combined H1 and H2 Antagonists. Annals of Emergency Medicine. 36:5 NOVEMBER 2000.
- ↑ Choo KJ, Simons E, Sheikh A: Glucocorticoids for the treatment of anaphylaxis: Cochrane systematic review. Allergy 2010; 65:1205-1211.
- ↑ Campbell RL, et al. Emergency department diagnosis and treatment of anaphylaxis: a practice parameter. Ann Allergy Asthma Immunol. 2014; 113:599e608.
- ↑ Schummer et al. The Pivotal Role of Vasopressin in Refractory Anaphylactic Shock. Anesthesia & Analgesia: August 2008 - Volume 107 - Issue 2 - pp 620-624.
- ↑ Dünser et al. Treatment of Anaphylactic Shock: Where Is the Evidence? Anesthesia & Analgesia: August 2008 - Volume 107 - Issue 2 - pp 359-361