EMT Chap 20: immunologic emergencies

Side effects of epinephrine

a. Increased pulse rate b. Anxiety c. Cardiac arrhythmias d. Pallor e. Dizziness f. Chest pain g. Headache h. Nausea i. Vomiting j. increase blood pressure

Allergic Reactions

-Almost 1,000 Americans die each year from allergic reactions -EMTs often respond to calls involving allergic reactions. -Most common causes of allergy-related emergencies involve: -Acute airway obstruction nCardiovascular collapse (shock) -You must be able to: -Handle and treat these life-threatening emergencies -Distinguish between the body's usual response to an allergen and an allergic reaction -Allergic reaction -Exaggerated immune response to any foreign substance (antigen) -Reactions can be mild and local or severe and systemic -Not caused directly by an outside stimulus: -Initial exposure to an antigen triggers formation of an antibody -Further exposures to the antigen produce antigen-antibody complexes that trigger an allergic reaction, causing the release of chemicals -Caused by the body's immune system -Antigen-antibody complex triggers the release of chemicals to combat stimulus -These chemical mediators cause physiologic changes in the body -Includes histamines and leukotrienes -Can present with symptoms from a runny nose to cardiac arrest -Substance enters the body by injection, inhalation, absorption or ingestion

Immunology

-Study of the body's immune system -The immune system protects the body from foreign substances and organisms -When a foreign substance invades the body: -The body goes on alert. -The body initiates a series of responses to inactivate the invader.

You must be able to:

-Treat these life-threatening complications -Distinguish between the body's usual response to an allergen and an allergic reaction Immunology is the study of the body's immune system

9.The adult EpiPen system delivers _____ mg of epinephrine, and the infant-child system delivers _____ mg. A.0.15, 0.3 B.0.3, 0.15 C.0.15, 0.5 D.0.5, 0.2

0.3, 0.15

As an EMT, you will often respond to calls involving an allergic reaction

1. Allergy-related emergencies may involve: a. Acute airway obstruction b. Cardiovascular collapse

Insect stings

1. Approximately 3% of adults and 1% of children are allergic to the venom of bees, wasps, and hornets, and allergic reactions to insect stings account for at least 50 deaths in the United States per year. 2. In about half of these deaths, the victim had never experienced a reaction to prior stings. 3. The stinging organ of most insects is a small, hollow spine projecting from the abdomen. 4. Venom can be injected through this spine directly into the skin. 5. Honeybees cannot withdraw their stinger. a. The honeybee flies away and dies. b. If the stinger is not removed, it can continue to inject venom for up to 20 minutes. c. Because they fly away, it is difficult to identify which species is responsible. 6. Wasps and hornets can sting multiple times. a. They do not die after stinging. 7. Some ants, especially the fire ant, also strike repeatedly, often injecting a particularly irritating toxin at the bite sites. 8. Applying ice sometimes makes stings and bites less irritating. i. The swelling associated with an insect bite may be dramatic and frightening. ii. As long as these manifestations remain localized, they are not usually serious.

Reassessment

1. En route to the hospital, repeat the primary assessment, reassess the patient's vital signs, and repeat a focused physical examination of the affected body systems. a. If the patient is unstable, reassess every 5 minutes; if the patient is stable, reassess every 15 minutes. b. The patient experiencing a suspected allergic reaction should be monitored with vigilance because deterioration of the patient's condition can be rapid and fatal. c. Monitor the patient's anxiety level and mental status. d. Watch for signs of shock and treat immediately if present. 2. Interventions a. Treatment is determined by the severity of the reaction. i. Mild reactions may require only supportive care and monitoring. ii. Anaphylaxis requires more aggressive treatment, including epinephrine and ventilatory support. iii. In either case, the patient should be transported to a medical facility for further evaluation. b. Recheck your interventions. i. You may need to give more than one injection of epinephrine. ii. Be sure to consult medical control before administering subsequent doses. iii. Even if the patient is experiencing relief, transport to the emergency department is still warranted because the medication's effect will wear off and symptoms will return. 3. Communication and documentation a. Documentation should include: i. Signs and symptoms found during the assessment ii. Reasons why you chose to provide the care you did iii. The patient's response to the treatment

Epinephrine

1. Epinephrine is a sympathomimetic hormone. a. It mimics the sympathetic (fight-or-flight) response. 2. It has various properties that cause the blood vessels to constrict, which reverses vasodilation and hypotension. 3. Other properties of epinephrine increase cardiac contractility and relieve bronchospasm in the lungs. 4. It can rapidly reverse the effects of anaphylaxis. 5. Epinephrine is prescribed by a physician and comes pre-dosed in an automatic epinephrine injector (EpiPen). 6. Some EMS systems are authorized to carry epinephrine as part of their regular on-board medications; in others, EMS providers may be permitted to help patients self-administer their own medication. 7. Refer to local protocols or consult online medical control. 8. All allergic emergency kits should contain a prepared, auto-injectable syringe of epinephrine. 9. The adult EpiPen system delivers 0.3 mg of epinephrine via a spring-loaded needle and syringe system; the infant-child system delivers 0.15 mg. 10. If the medication has expired or is discolored, do not give the medication. Inform medical control and continue to provide emergency transport. 11. See Skill Drill 20-1 to use an EpiPen auto-injector. 12. Epinephrine can have an effect within 1 minute, so it is the primary way to save the life of someone with a severe anaphylactic reaction. 13. Because epinephrine constricts blood vessels, it may cause the patient's blood pressure to rise significantly. 14. Patients without signs of respiratory compromise or hypotension and who do not meet the criteria for a diagnosis of anaphylaxis should not be given epinephrine. 15. Some areas may allow administration of epinephrine by intramuscular injection. a. With IM epinephrine injection, the concentration must be 1:1,000. b. Find out if your protocols allow for epinephrine IM injection.

History taking

1. Investigate the chief complaint or history of present illness. Identify signs and symptoms. 2. SAMPLE history a. If the patient is responsive, obtain the SAMPLE history (including OPQRST) and ask him or her the following questions specific to an allergic reaction: i. Have any interventions already been completed? ii. Has the patient experienced a severe allergic reaction in the past? 3. Be alert for any statements regarding the ingestion of foods that commonly cause allergic reactions. 4. Inquire about the presence of gastrointestinal complaints such as nausea and vomiting.

Anaphylaxis is an extreme, life-threatening allergic reaction.

1. Involves multiple organ systems 2. In severe cases, it can rapidly result in shock and death. 3. Three common signs: a. Urticaria (hives) i. Small areas of generalized itching or burning that appear as multiple, small, raised areas on the skin b. Angioedema i. Areas of localized swelling c. Wheezing i. A high-pitched, whistling breath sound that is typically heard on expiration ii. Results from bronchospasm/bronchoconstriction and increased mucus production 4. You may also note hypotension due to vasodilation, as well as increased capillary permeability. 5. An often-overlooked symptom of patients experiencing an allergic reaction is persistent gastrointestinal dysfunction (eg, nausea, vomiting, and abdominal cramps)

Secondary assessment

1. Physical examination a. If indicated, perform a rapid exam of the body from head to toe, or conduct a physical examination focused on the area(s) of chief complaint. b. If the patient is unconscious or otherwise unable to communicate: i. Remove clothing as necessary and look for the presence of bee stingers, signs of contact with chemicals, and other clues suggestive of a reaction. ii. Look for a medical alert tag that could indicate a severe allergy. c. If you have not already done so, auscultate for abnormal breath sounds such as wheezing or stridor, and carefully inspect the skin for swelling, rashes, or urticaria. d. If a systemic reaction continues, the body will have difficulty supplying blood and oxygen to the vital organs. Altered mental status is one of the first signs. 2. Vital signs a. Vital signs indicate whether the body is compensating for the stress imposed on the body by the reaction. b. Assess baseline vital signs, including pulse and respiratory rates, blood pressure, pupillary response, and oxygen saturation. c. Skin signs may be unreliable indicators of hypoperfusion, as they may vary widely or be hidden by rashes and swelling. 3. Monitoring devices i. In a patient experiencing an allergic reaction, pulse oximetry can be a useful method for assessing the patient's perfusion status. ii. The decision to apply oxygen should be based on airway patency, work of breathing, and abnormal lung sounds on auscultation, not solely on pulse oximetry readings.

Primary assessment

1. Quickly identify and treat any immediate or potential life threats. a. Assess the patient's airway, breathing, and circulation (ABCs), as deterioration can occur at almost any time and with very little warning. ABCs should be reassessed repeatedly throughout transport. 2. Form a general impression. a. Allergic reactions may present as a respiratory condition or as cardiovascular distress in the form of shock. b. Patients experiencing a severe allergic reaction will often appear very anxious. c. If your general impression finds the person anxious and in distress, immediately call for ALS backup if available. d. Look for a medical identification tag if the patient is found unresponsive or is unable to answer questions. 3. Airway and breathing a. Anaphylaxis can cause rapid swelling of the upper airway. i. You may have only a few minutes to assess the airway and provide life-saving measures. b. Not all allergic reactions are anaphylactic reactions. i. Work quickly to assess the patient to determine the severity of the symptoms and the number of body systems affected. c. Quickly assess for increased work of breathing, use of accessory muscles, head bobbing, tripod positioning, nostril flaring, and abnormal breath sounds. i. Wheezing is due to narrowing of the air passages, resulting from contraction of muscles around the bronchioles in reaction to the allergen, and mobilization of mucus in an attempt to "push out" the allergen. ii. As the patient's condition worsens, breathing may diminish to the point of being almost silent. iii. Stridor, a harsh, high-pitched sound heard on inspiration, can eventually lead to total obstruction. iv. The patient may eventually fatigue and may even stop breathing. In the latter case, cardiac arrest will shortly follow respiratory arrest. d. Assist the patient into a comfortable position, generally in a high Fowler's position, to maximize ventilations. e. If signs of shock emerge, immediately place the patient in the supine position, as tolerated. f. Listen to the lungs on each side of the chest. Do not hesitate to initiate high-flow oxygen therapy. g. For a patient in severe respiratory distress, you may have to assist ventilations using a bag-valve mask, attached to a high concentration of oxygen. 4. Circulation a. Some patients in anaphylaxis may present with signs and symptoms of circulatory distress, such as hypotension. b. Palpate for the presence and quality of a radial pulse. c. Assess for a rapid pulse rate; pale, cool cyanotic or red, moist skin; and delayed capillary refill, all of which may indicate hypoperfusion. d. Treatment for shock: i. Oxygen ii. Positioning (recumbent or supine as tolerated) iii. Preventing the loss of body heat e. The definitive treatment for anaphylactic shock is epinephrine. 5. Transport decision a. If anaphylaxis is suspected, or if a relatively mild allergic reaction appears to be worsening, immediate transport is warranted. i. Take along the patient's medications (eg, auto-injectors and inhalers). ii. If the patient is calm and does not exhibit severe symptoms, consider continuing the assessment, but err on the side of emergency transport.

Scene size-up immunologic emergency

1. Scene safety a. The patient's environment or recent activity may indicate the source of the allergic reaction. i. Sting or bite from an insect ii. Food allergy at a restaurant iii. New medication regimen b. A respiratory problem reported by dispatch may be an allergic reaction. i. Until a field impression of allergic reaction is firmly established, be mindful of other potential causes of respiratory distress. ii. Traumatic injury may also be present, secondary to the medical emergency. c. Follow standard precautions, with a minimum of gloves and eye protection. d. Consider the need for additional resources, such as advanced life support (ALS) personnel.

10.When administering epinephrine by auto-injector, the EMT should hold the injector in place for: A.5 seconds. B.10 seconds. C.20 seconds. D.30 seconds.

10 seconds

4.What is a wheal? A.A raised, swollen, well-defined area on the skin B.An area of localized swelling involving the lips, tongue, and larynx C.Generalized itching or burning that appears as multiple, small, raised areas on the skin D.An exaggerated immune response to any substance

A raised, swollen, well-defined area on the skin

Pathophysiology

A. An allergic reaction is an exaggerated immune response to any substance. 1. It is not caused directly by an outside stimulus, such as a bite or sting. 2. Rather, it is caused by the body's immune system, which releases chemicals to combat the stimulus. a. These chemicals include histamines and leukotrienes, both of which contribute to an allergic reaction. b. Given the right person and the right circumstances, almost any substance can become an allergen. i. First, the person becomes sensitized (exposed for the first time) to the substance. ii. Then, his or her immune system learns to recognize the substance. iii. When the patient is exposed to the substance again, an allergic reaction occurs. 3. Some patients may not know what is causing their allergic reaction, so you must be able to recognize the signs and symptoms and maintain a high index of suspicion. 4. An allergic reaction may be: a. Mild and local, characterized by itching, redness, and tenderness b. Severe and systemic, a condition known as anaphylaxis

Emergency Medical Care of Immunologic Emergencies

A. If the patient appears to be having a severe allergic (or anaphylactic) reaction: 1. Administer BLS. 2. Provide prompt transport to the hospital. 3. If a stinger is present, scrape the skin with the edge of a sharp, stiff object such as a credit card (do not use tweezers or forceps). a. Gently wash the area with soap or mild antiseptic. b. Remove jewelry from the area before swelling begins. c. Position the injection site slightly below the level of the heart. d. Apply ice or cold packs to the area, but not directly on the skin and not for more than 10 minutes at a time. 4. Be alert for signs of airway swelling and other signs of anaphylaxis such as nausea, vomiting, and abdominal cramps, and do not give the patient anything by mouth. 5. Place the patient in the supine position as indicated, and give oxygen if needed. 6. Monitor the patient's vital signs, and be prepared to provide further support as needed

Anatomy and Physiology of immune sys

A. The immune system protects the body from foreign substances and organisms. B. When a foreign substance invades the body: 1. The body goes on alert. 2. The body initiates a series of responses to inactivate the invader.

Common Allergens

A. The most common allergens fall into one of the following five general categories. 1. Food a. Certain foods (eg, shellfish, peanuts) may be the most common trigger of anaphylaxis. i. These foods account for 30% of deaths from anaphylaxis, most commonly in adolescents and young adults. b. Symptoms: i. May take more than 30 minutes to appear ii. May not include skin signs (eg, hives) iii. The reaction can be severe and involve the respiratory and/or cardiovascular systems. 2. Medication a. Medications are the second most common source of anaphylactic reactions, particularly antibiotics (eg, penicillin) and nonsteroidal anti-inflammatory drugs (NSAIDs). b. If the medication is injected, the reaction may be immediate (within 30 minutes) and severe. c. Reactions to oral medications may take more than 30 minutes to appear, but can also be very severe. 3. Plants a. Dusts, pollens, and other plant materials can cause a rapid and severe allergic reaction. b. Common plant allergens include ragweed, ryegrass, maple, and oak. 4. Chemicals a. Certain chemicals, makeup, soap, hair dye, latex, and various other substances can cause severe allergic reactions. b. Latex is of particular concern to health care providers; patients can be sensitive to it, and as many as 12% of health care providers become sensitized to latex. i. Use latex alternatives such as nitrile gloves. 5. Insect bites and stings a. When an insect (eg, a honeybee, wasp, ant, yellow jacket, or hornet) bites or stings a person, the act of injecting its venom is called envenomation. b. The reaction can be localized, causing swelling and itching at the site, or it may be a severe and systemic reaction (ie, anaphylaxis).

7.The MOST reliable indicator of upper airway swelling during a severe allergic reaction is: A.stridor. B.anxiety. C.cyanosis. D.wheezing.

A.stridor.

6.A young male is experiencing signs and symptoms of anaphylactic shock after being stung by a scorpion. His level of consciousness is diminished, his breathing is severely labored, you can hear inspiratory stridor, and his face is cyanotic. The patient has a prescribed epinephrine auto-injector. What should you do first? A.Assist him in administering his epinephrine. B.Apply high-flow oxygen via nonrebreathing mask. C.Provide ventilatory assistance with a bag-valve mask. D.Elevate his legs and cover him with a warm blanket.

Answer: C Rationale: The patient is not breathing adequately, as noted by his decreased level of consciousness, severely labored breathing, inspiratory stridor, and cyanosis. Therefore, you should first assist his ventilations with a bag-valve mask. He clearly requires epinephrine, but not before restoring adequate breathing first. Regardless of the situation, a patient's airway must be patent and his or her breathing must remain adequate at all times.

5.You are treating a woman who was stung numerous times by hornets. On assessment, you note that some of the stingers are still embedded in her skin. You should: A.leave the stingers in place. B.scrape the stingers from her skin. C.pull the stingers out with tweezers. D.cover the stings with tight dressings.

B.scrape the stingers from her skin.

3.You are called to a local baseball park for a 23-year-old man with difficulty breathing. He states that he ate a package of peanuts approximately 30 minutes ago and denies any allergies or past medical history. Your assessment reveals widespread urticaria, tachycardia, and a BP of 90/60 mm Hg. You can hear him wheezing, even without a stethoscope. You should be MOST suspicious of a(n): A.acute asthma attack. B.mild allergic reaction. C.anaphylactic reaction. D.moderate allergic reaction.

C.anaphylactic reaction.

2.The negative effects associated with anaphylactic shock are the result of: A.severe internal fluid loss. B.inadequate pumping of the heart. C.vasodilation and bronchoconstriction. D.the nervous system's release of adrenaline.

C.vasodilation and bronchoconstriction.

8.The most common trigger of anaphylaxis is: A.plants. B.chemicals. C.medications. D.food.

D.food.

Signs and symptoms of insect stings

a. Sudden pain b. Swelling c. Localized heat d. Widespread urticaria e. Redness in light-skinned individuals f. Itching and possibly a wheal (raised, swollen, well-defined area on the skin) In more severe (anaphylactic) cases, patients may experience: a. Bronchospasm and wheezing b. Chest tightness and coughing c. Dyspnea d. Anxiety e. Gastrointestinal complaints f. Hypotension g. Occasionally, respiratory failure h. If untreated, an anaphylactic reaction can proceed rapidly to death. i. More than two-thirds of patients who die of anaphylaxis do so within the first 30 minutes, so rapid treatment and transport is essential.

1.The signs and symptoms of an allergic reaction are caused by the release of: A.histamine. B.epinephrine. C.leukotrienes. D.both histamine and leukotrienes.

both histamine and leukotrienes The two chief chemicals released by the body that result in the signs and symptoms of an allergic reaction are histamines and leukotrienes. Epinephrine (adrenaline) is used to treat allergic reactions. Glucagon is a hormone secreted by the pancreas that helps control metabolism.

immunology

the study of the body's immune system, and the five categories of stimuli that may provoke an allergic reaction.