How To Use an Epi Pen to Treat Severe Allergic Reactions

An Epi Pen, or epinephrine auto-injector, is a treatment for severe allergic reactions (also known as anaphylaxis) resulting in respiratory distress and/or shock (hypoperfusion).  An Epi Pen administers an exact dosage of epinephrine to the patient.  Adult Epi Pens deliver a single dose of .3 mg and should be used on any patient weighing more than 66 lbs.  The Epi Pen Jr. delivers .15 mg of epinephrine and should be used on children weighing less than 66 lbs.

Allergic reactions can be caused by a variety of environmental factors including, but not limited to insect, snake or spider venom, food products, medications and pollen. Most people who are aware that they may experience a life-threatening allergic reaction will have an Epi Pen prescribed to them.  An Epi Pen will automatically inject its dose of liquid epinephrine into a patient when the safety cap is removed and the auto-injector is placed firmly against the patient's thigh.  If you are ever in a situation where someone is experiencing an anaphylactic reaction, you should not hesitate to administer the patient's prescribed Epi Pen.

Two major indicators of anaphylaxis (a severe allergic reaction) are respiratory compromise-difficulty breathing, potentially including wheezing-and shock-weak pulse, rapid heartbeat, low blood pressure, decreased mental status.  The speed with which an allergic reaction occurs after exposure to the offending allergen is also an indicator of how severe the reaction will ultimately be.  Most anaphylactic reactions occur within 20 minutes of exposure to an allergen, but reaction time can vary from seconds to hours.  Nevertheless, the general rule is that the faster the allergic reaction occurs, the more severe the reaction will be.

To treat a severe allergic reaction with an Epi Pen:

1. Direct a bystander to call 911.  Have someone nearby immediately call 911 and explain the medical emergency in as much detail as possible.  Anaphylactic reactions can cause a patient's airway to swell shut, which is a problem that only paramedics can effectively treat at the scene.  Make to sure to get an ambulance dispatched as soon as possible.  Time is the most important factor in an anaphylactic emergency-the sooner a patient is treated, the better his or her odds are for a full recovery.

2. Establish and maintain an airway.  Your first concern with any emergency medical situation should always be the patient's airway.  Since respiration is oftentimes compromised in a severe allergic reaction, this is an important step.  Utilize the head-tilt, chin-lift or jaw-thrust maneuver as described in How To Perform CPR, if necessary.
3. Suction any secretions and maintain oxygen therapy if possible.  Clearly this is not always possible, but you should do your best.  Remove any secretions or vomit from the patient's mouth by rolling him on his side and allowing the contents to drain.  If oxygen is available and you're comfortable administering it to the patient, do so.
4. Be prepared to perform mouth-to-mouth.  If the patient's breathing is inadequate, it is necessary that you assist her respirations by breathing for her.  Use the mouth-to-mouth breathing technique described in How To Perform CPR.
5. Determine that the patient is suffering an anaphylactic reaction.  The only indication for administering an Epi Pen is that the patient is, indeed, suffering a severe allergic (or anaphylactic) reaction.  The two major indicators of a severe allergic reaction are difficulty breathing and shock (hypoperfusion).  Other signs and symptoms may include:
   • itching
   • hives
   • widespread flushed skin
   • cyanosis (blue coloring around the lips and other mucus membranes that indicates inadequate oxygenation)
   • severe edema (swelling)
   • tachycardia (significantly increased heart rate)
   • hypotension (low blood pressure)
   • weak or absent peripheral pulses
   • decreased mental status
   • respiratory distress, including wheezing and/or stridor (a high-pitched sound heard upon inhalation that indicates swelling of the larynx)

6. Administer an Epi Pen. If the patient has an Epi Pen prescribed to him, has potentially been exposed to an allergen (look for other signs and symptoms that may indicate an allergic reaction) and is experiencing difficulty breathing and/or shock, administer the Epi Pen now.  To do so: 
   1. Check that the medication has not expired.
   2. Remove the safety cap from the auto-injector.
   3. Place the tip of the auto-injector on the outside of the patient's thigh, mid-way between his hip and knee.
   4. Push the Epi Pen firmly against the patient's thigh until the needle is deployed and the epinephrine has been injected.
   5. Dispose of the Epi Pen in a biohazard container, being careful not to prick yourself or those around you with the now-exposed needle.
   6. Note the dose of epinephrine that was given and the time it was administered.

7. Transport the patient to the hospital.  Typically you should wait for an ambulance to arrive to transport the patient to the hospital.  However, since time is critical in a severe allergic reaction, there may be situations where you should drive the patient to the hospital yourself.  If you're unsure about whether or not to wait for the ambulance to arrive, ask the 911 dispatcher what you should do.  Always transport a patient who has received an Epi Pen injection to the hospital.  The effects of the epinephrine dose could wear off in as little as 10 to 20 minutes.