Epinephrine & To Stick or Not To Stick William Hurley, MD FACEP Harborview Medical Center hurleyw@u.washington.edu Washington Poison Center hurley@wapc.org
Epinephrine & Describe common initiators of anaphylaxis. Describe the physiological process of anaphylaxis. Describe the management anaphylaxis. List the indications for epinephrine in the management of anaphylaxis. List the contraindications for epinephrine in the management of anaphylaxis
- Definition Serious allergic reaction Rapid in onset and may cause death (IgE mediated) Anaphylactoid (non-ige) Identical treatment Whiteside M, Fletcher A. Anaphylactic shock: no time to think. J R Coll Physicians Edinb. 2010 Jun;40(2):145-7.
Severity varies greatly Mild urticarial rash over hours Airway obstruction by edema in minutes Acute reactions Prompt recognition & management save lives Confusion over dose & use of epinephrine Jose R, Clesham GJ. Survey of the use of epinephrine for anaphylaxis by junior hospital doctors. Postgrad Med J 2007;83:610 11
Epidemiology True rate unknown (under-reporting) Lifetime prevalence ~ 75 per 100,000 Increasing Most common sixth & seventh decades Trigger factors change with age Food in adolescents & young adults Rate increases with socio-economic circumstances (medications)
Causes of Drugs Blood products Foods Stings
Causes of Drugs Blood products Foods Stings NSAIDS, aspirin, antibiotics, colloids, vitamin K, contrast media Packed cells, immunoglobulins, vaccines Eggs, peanuts, shellfish Bees, wasps, fire ants
Signs & Symptoms of Cardiovascular system Respiratory system Skin Facial Others
Signs & Symptoms of CV system Resp system Skin Facial Others Tachycardia, hypotension Bronchospasm, laryngeal edema, stridor Urticaria, erythema, angio-edema Facial edema, rhinitis, conjunctival edema Diarrhea, vomiting, metallic taste, confusion
Mechanisms of Degranulation of basophils & mast cells Release mediators Histamine, tryptase, interleukins Due to re-exposure of sensitized cells (IgE) Or another non-immunological mechanism Clinically, mechanisms are indistinct. Most common; urticaria (73%), itch (43%), dyspnea (29%), hypotension (10%)
Clinical Criteria for Acute onset illness (minutes to hours) Involvement of skin, mucosal tissue or both And at least one of the following: Respiratory compromise Reduced BP (<90 mmhg systolic) Symptoms of end-organ dysfunction Hypotonia, collapse, syncope
Acute Management of Rapid airway, breathing & circulation (ABC) assessment A should also include allergen removal Immediate treatment with IM epinephrine Delay in epinephrine administration is associated with more adverse outcomes (death) Time from exposure to cardiac arrest can be as short as one minute (IV medications)
Epinephrine in Alpha-adrenergic vasoconstrictive Reverses peripheral vasodilatation; alleviates hypotension, reduces angioedema & urticaria Beta-adrenergic stimulant properties Bronchodilatation, increase myocardial output & contractility, suppress further mediator release
Acute Management of ABC s Epinephrine Oxygen Treatment of shock Laid flat with legs elevated IV fluid challenge (500 1000 ml crystalloid) Up to 35% of circulating volume may extravasate
Acute Management of ABC s Epinephrine Oxygen Treatment of shock Laid flat with legs elevated IV fluid challenge (500 1000 ml crystalloid) Up to 35% of circulating volume may extravasate Others?
Acute Management of ABC s, Oxygen Epinephrine Treatment of shock, IV fluid Bronchospasm; beta-agonists (Albuterol) Corticosteroids (action in 2-4 hours) Methylprednisolone, Prednisone Antihistamines (H1 & H2 blockers) Diphenhydramine, Ranitidine Primary impact on urticaria & itching
Epinephrine Side Effects Mild Anxiety, tremor, tachycardia, elevated BP Severe (usually IV) Arrhythmias, Myocardial infarction, Stroke (CVA), Pulmonary edema Relative Contraindications Severe ischemic heart disease & stroke (CVA) In anaphylactic shock, benefit outweighs risks
WA EMT Basic Field Protocol (2005) I. Scene Size-Up / Initial Patient Assessment II. Focused History & Physical Examination III. Management IV. On-Going Assessment V. Transport http://www.doh.wa.gov/hsqa/emstrauma/down load/emtbprot.pdf
67 Year-Old Male after Hornet Sting WA EMT Basic Field Protocol (2005) I. Scene Size-Up / Initial Patient Assessment II. Focused History & Physical Examination III. Management IV. On-Going Assessment V. Transport
67 Year-Old Male after Hornet Sting I. Scene Size-Up / Initial Patient Assessment Hornet nest in workshed outside, few around Complaining of weakness Awake, talking
67 Year-Old Male after Hornet Sting II. Focused History & Physical Examination Prior History - Hypertension No history of allergic reactions. (Has been stung)
67 Year-Old Male after Hornet Sting II. Focused History & Physical Examination Prior History - Hypertension No history of allergic reactions. (Has been stung) Level of Consciousness - Alert, becoming somnolent Upper Airway Facial swelling, no hoarseness or stridor Lower Airway - Prolonged expirations, wheezing Skin Red, swelling, urticaria (hives) Vital Signs P 110, BP 94/50
67 Year-Old Male after Hornet Sting III. Management Remove offending agent (stinger) Open airway & provide oxygen Pulse Oximetry (if available)
Remove the Stinger Don t squeeze the venom sac Pull with fingers Scrape with credit card Honey Bee
67 Year-Old Male after Hornet Sting III. Management No stinger to remove Airway open, oxygen administered (15 L NRB mask) Increasing respiratory distress Pulse rate rises to 140 Pulse Oximetry falls to 88%
67 Year-Old Male after Hornet Sting III. Management Remove offending agent (stinger) Open airway & provide oxygen Severe respiratory distress Circulation Epinephrine 1:1,000 (Auto-injector) Adult (>30 kg = 66 lbs) 0.3 ml Pediatric (<30 kg = 66 lbs) 0.15 ml Approval of on or off-line medical control Record time & re-assess each 2 minutes Pulse Oximetry (if available)
Epinephrine - Indications IM (0.15-0.3 ml 1:1,000) Acute anaphyactic illness Life-threatening symptoms Airway (pharyngeal edema) Breathing (bronchospasm) Circulation (hypotension) IV Cardiac Arrest 10 ml 1:10,000 = 1 mg Do not give 1:1,000 epinephrine IV
Epinephrine Contra-Indications IM (0.15-0.3 ml 1:1,000) Severe hypertension (above 180/100) Acute cardiac ischemia Unless in Anaphylactic Shock Acute Stroke (CVA) IV Cardiac Arrest (10 ml 1:10,000) Patient not in Cardiac Arrest Do not give epinephrine IV for asthma, allergic reaction (unless in cardiac arrest)
67 Year-Old Male after Hornet Sting III. Management Indications; Wheezing, Hypotension Contraindications; None Epinephrine 1:1,000 (Auto-injector) Adult (>30 kg = 66 lbs) 0.3 ml Approval of on or off-line medical control Record time & re-assess each 2 minutes
67 Year-Old Male after Hornet Sting Treated with Epinephrine 0.3 ml IM at home. Progressive improvement enroute to hospital Hypotension persists for 1 hour Treated with additional dose of epinephrine Admitted to hospital Treated with Diphenhydramine, Ranitidine, Methylprednisolone. Monitored overnight Discharged home next day Epi-Pen & Allergy Referral.
67 Year-Old Male after Hornet Sting I. Scene Size-Up / Initial Patient Assessment II. Focused History & Physical Examination III. Management IV. On-Going Assessment V. Transport
67 Year-Old Male after Hornet Sting III. Management Remove offending agent (stinger) Open airway & provide oxygen Severe respiratory distress Circulation Epinephrine 1:1,000 (Auto-injector) Adult (>30 kg = 66 lbs) 0.3 ml Pediatric (<30 kg = 66 lbs) 0.15 ml Approval of on or off-line medical control Record time & re-assess each 2 minutes Pulse Oximetry (if available)
Epinephrine Use by EMT s Cases treated by EMTs with epinephrine for presumed anaphylaxis 2000-2003 King County, WA (n = 22) EMTs used epinephrine for presumed anaphylaxis in a discriminating manner Typically agreed with physician review No major adverse events. Rea TD, et al. Epinephrine use by emergency medical technicians for presumed anaphylaxis. Prehosp Emerg Care (2004) Oct-Dec;8(4):405-10.
Intracranial Hemorrhage after IM Epinephrine for Allergic Reaction Rare case ICH from 0.3 ml IM epinephrine after allergic reaction 65-yo woman wasp sting to the tongue Epi-Pen at Student Health Center Successful craniotomy & evacuation Unclear severity of tongue swelling & BP Levis JT, et al. Intracranial Hemorrhage after Prehospital Administration of Intramuscular Epinephrine. J Emerg Med (2008) Aug 30.
Epinephrine & Describe common initiators of anaphylaxis. Describe the physiological process of anaphylaxis. Describe the management anaphylaxis. List the indications for epinephrine in the management of anaphylaxis. List the contraindications for epinephrine in the management of anaphylaxis
Epinephrine & To Stick or Not To Stick William Hurley, MD FACEP Harborview Medical Center hurleyw@u.washington.edu Washington Poison Center hurley@wapc.org