Emergency Information and Recommendations from Canadian Allergists
Canadian allergists recommend the following six key points for dealing with anaphylaxis as stated in Anaphylaxis in Schools & Other Settings, 3rd Edition Revised.
1. Epinephrine is the first line medication that should be used for the emergency management of a person having a potentially life-threatening allergic reaction.12
In studies of individuals who have died as a result of anaphylaxis, epinephrine was underused, not used at all, or administration was delayed.6-9 The course of an anaphylactic episode cannot be predicted with certainty and may differ from one person to another and from one episode to another in the same person.5 It is recommended that epinephrine be given at the start of a known or suspected anaphylactic reaction. Epinephrine should be injected into the muscle of the mid-outer thigh.
2. Antihistamines and asthma medications should not be used instead of epinephrine for treating anaphylaxis.1,3,4
While they will do no harm when given as additional or secondary medication, they have not been proven to stop an anaphylactic reaction. Epinephrine is the only treatment shown to stop an anaphylactic reaction. The main benefit of antihistamines is in treating hives or skin symptoms.
3. All individuals receiving epinephrine must be transported to hospital immediately (ideally by ambulance) for evaluation and observation.
It is optimal to have individuals transported to hospital by paramedics or local emergency medical services. While epinephrine is usually effective after one injection, the symptoms may recur and further injections may be required to control the reaction. Repeat attacks have occurred hours later without additional exposure to the offending allergen.13-15 Therefore, it is recommended that a person suffering from an anaphylactic reaction be observed in an emergency facility for an appropriate period because of the possibility of either a “biphasic” reaction (a second reaction) or a prolonged reaction.13,14 For most individuals, a reasonable length of observation time is 4 to 6 hours. This time may vary depending on the judgment of the attending physician who will take into consideration factors such as the severity of the reaction, the person’s response to treatment, previous episodes, and distance from the hospital to the person’s home. More caution should be used in people with asthma because most fatalities associated with anaphylaxis occur in these individuals.14 Upon discharge from hospital, an epinephrine auto-injector prescription should be obtained and immediately filled, if not already available.
4. Additional epinephrine should be available during transport to hospital. A second dose of epinephrine may be given as early as 5 minutes after the first dose if there is no improvement in symptoms. 3,16
The second dose of epinephrine should only be given in situations in which the allergic reaction is worsening or not improving.
Signs that the reaction is worsening are that the patient’s breathing becomes more difficult or there is a decreased level of consciousness. Individuals who have been prescribed epinephrine are advised to have at least one epinephrine auto-injector with them at all times. It is important for people at risk of anaphylaxis to take extra precautions (e.g. packing a back-up auto-injector) when planning trips or camping outdoors. When travelling, they should try to be within a reasonable distance of a medical facility should an emergency occur.
5. Individuals with anaphylaxis who are feeling faint or dizzy because of impending shock should lie down unless they are vomiting or experiencing severe respiratory distress.17
To improve blood circulation, caregivers should assist in lifting the person’s legs and keeping the legs raised by putting something (e.g. a pillow) underneath. The person should continue to lie down until emergency responders arrive or until they have fully recovered. If the person feels nauseated or is vomiting, lay the person on his or her side to keep the airway clear and prevent choking on vomit.
(Note: Individuals having difficulty breathing should be kept sitting up.)
Do not make the person sit or stand immediately following a reaction (even if treated) as this could result in another drop in blood pressure.17
Individuals at risk should be advised to seek help when experiencing an allergic reaction and not to go off alone (e.g. to the washroom) if they are feeling unwell. If they are alone and lose consciousness, no one will know they need help.
6. No person experiencing anaphylaxis should be expected to be fully responsible for self-administration of an epinephrine auto-injector.
Individuals may not physically be able to self-administer epinephrine when they are suffering from a reaction. They may be anxious about using a needle, may downplay the seriousness of a reaction, or may not want to draw attention to themselves. They may also be confused. Assistance from others, especially in the case of children or teens, is crucial in these circumstances.