Allergy Flashcards
anaphylactic rxn onset
will start w/in 30 minutes after antigen exposure, often immediately. IV antigen will produce the most severe rxn and orally ingested can be delayed up to 3 hrs. the more immediate the rxn, the more severe it is
anaphylactic rxn course
mild reaction will resolve within 30 minutes. Symptoms for all will peak within minutes. A small percentage of people will have a biphasic course. the important thing to remember is that half of all anaphylactic fatalities occur within the first hour so fast recognition and treatment is key as well as continued monitoring.
3 conditions that must be met for anaphylaxis to occur
exposure to an antigen (IgE ab formation), a latent period (mast cell and basophil sensitization), and re-exposure to antigen
principle COD in anaphylaxis
laryngeal edema. Do not hesitate to intubate early
2nd MCC COD in anaphylaxis
Hypotension. give large fluid bolus to help.
most anaphylactic deaths are from what agent?
IV PCN
2nd most common cause of life threatening anaphylaxis
hymenoptera venoms. honeybee will leave the stinger in, must remove!
high risk its for RCM
previous severe rxn, atopy/allergies/asthma, cardiac and renal patients. Shellfish allergy is not a contraindication
protocol for high risk RCM or previous RCM rxn
PO prednisone 50 mg @ 13, 7 and 1 hour before procedure. Diphenhydramine 50 mg IM x1 right before procedure. consider ephedrine 25 mg PO 1 hr before procedure and consider H2 antagonist (ranitidine) PO 3 hrs before procedure.
All patients stop metformin 48 hrs prior to procedure. If do not do this must give 3-4 L of fluid.
initial management of anaphalaxis
ABC’s- give epinephrine ASAP
EpiPen, pre-filled, can give SQ x2 before get to ED
Management of anaphylaxis in ED
remove triggering agent (may need to tourniquet proximal to the site). If pt is hypotensive place in trendelenberg position and give rapid IV 500 ml NS bolus w/in first 5 minutes. Set up on the cardiac monitor, ECG stat, and give O2. Always be prepared for ET intubation. Start on med protocol
emergent med protocol for anaphylaxis
Diphenhydramine 50 mg IV bolus + Methylprednisolone 125 mg IV bolus + 0.3mg epic IM q 5-15 min pro + inhaled albuterol 10mg/hr + ranitidine 50 mg IV bolus
long term medical management of anaphylaxis
methylprednisolone 1-2 mg/kg/day BID x 5 days (medrol dose pack) + cetirizine 10 mg BID x 5-7 days + ranitidine 150 mg PO BID x 5 days
anaphylaxis dispisition
stable and responsive to meds will have to observe in ED x 4 hrs if received epi. D/c home with pt education, rx for 2 epi-pens and referral to allergist
