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Allergic Reactions and Envenomations

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					16: Allergic Reactions and Envenomations
     Allergic Reactions
     All   i R    ti
       g
• Allergic reaction
   – Exaggerated immune response to
     any substance
• Histamines and leukotrienes
   – Chemicals released by the
     immune system
     i            t
                    Anaphylaxis
                    A   h l i
•                  g
    Extreme allergic reaction
•   Involves multiple organs
•   Can rapidly result in death
•   Most common signs:
     – Wheezing
     – Urticaria (hives)
Severe All
S            i R    ti
       Allergic Reaction
Five G   l All      C t    i
Fi General Allergen Categories
      •                        g
          Insect bites and stings
      •   Medications
      •   Plants
      •   Food
      •   Chemicals
      Insect Bites and Stings
      I    t Bit     d Sti
                        g
• Death from insect stings outnumber those
  from snakebites.
             j           g      g g g
• Venom is injected through stinging organ.
• Some insects and ants can sting
  repeatedly.
    p      y
      Signs and Symptoms
      Si      dS    t
           p ,        g,
• Sudden pain, swelling, and
  redness at site
• Itching and sometimes a
  wheal
• Sometimes dramatic
  swellings
Removing Sti
R    i   Stingers
Anaphylactic Reactions to Stings
A   h l ti R     ti    t Sti
    %        people          g
 • 5% of all p p are allergic to bee, ,
   hornet, yellow jacket, and wasp stings.
      p y                    pp         y
 • Anaphylaxis accounts for approximately
   200 deaths a year.
 • Most deaths occur within half an hour of
   being stung.
           Signs and Symptoms
            of Allergic Reaction
• Itching and burning        • Chest tightness and
• Widespread urticaria         coughing
• Wheals                     • Dyspnea
• Swelling of the lips and   • Anxiety
  tongue                     • Abdominal cramps
• Bronchospasm and           • Hypotension
  wheezing
              p
• You are dispatched to a p            possible allergic
                            park for a p             g
  reaction.
• You arrive to find a crowd of onlookers around a
                                     You are the Provider



  25-year-old man.
• He appears very anxious and has hives all over his
             arms.
  chest and arms He thinks he was stungstung.
• He says it is hard to breathe, and is dizzy.
        yp                               g
• What type of reaction is this man having?
• What vital signs would you expect?
• What is your next step?
                                    You are the Provider (continued)
              Scene Size-up




• Remember crew safety.
• Check environment for source of the reaction—
  insects, foods, medications.
• Call ALS immediately if reaction is serious, as in
       case
  this case.
          g
• Vital signs are:
   – BP 94/56 mm Hg           You are the Provider (continued)



   – Pulse 130 beats/min
   – Respirations 42 breaths/min
   – Pulse oximetry 90%
• You explain that you need to administer
  epinephrine, then administer it.
• Your partner administers high-flow oxygen and
            the ti
  removes th stinger.
• You have patient lie down with feet propped up.
                Initial Assessment




• General impression
  – May present as respiratory distress and/or
    cardiac distress in the form of shock.
  – Patients may feel sense of impending doom.
    Check         f ll f    di l identification tags.
  – Ch k carefully for medical id tifi ti t
  – See what treatment has been administered prior
    to your arrival.
  – If unresponsive, immediately evaluate and treat
    life threats.
           Airway and Breathing
           Ai       dB    thi
          y     y
• You may only have a few
  minutes to assess the airway
  and provide lifesaving measures.
• Place conscious patient in tripod
  position.
• Quickly listen to lungs for
  wheezing.
• Provide high-concentration
             g
  oxygen via nonrebreathing
  mask, but be prepared to assist
                       necessary
  with ventilations if necessary.
                   Circulation
                   Ci   l ti
                                     y
• Look for indications of circulatory distress.
• If unresponsive without a pulse, begin CPR and
  AED resuscitation.
• Rapid heart rate; cool, moist skin; and delayed
  capillary refill times indicate hypoperfusion.
           Transport Decision
           T       tD i i
        p promptly.
• Transport p     p y
• Take patient medications and auto-injectors
  with you.
• Treat respiratory distress and shock, then
  transport immediately.
             Focused History and Physical Exam




• Unresponsive patients receive a rapid physical
  exam.
• For responsive patients, obtain a SAMPLE history.
• SAMPLE history helps determine:
     History of specific allergies
   – Hi t      f      ifi ll i
   – If patient carries medication for an allergy
   – If reaction is related to food or environment
          Focused Physical Exam
          F     d Ph i l E
                p      y y     ,         y y     ,
• Evaluate respiratory system, circulatory system,
  mental status, and skin.
• Be alert for altered mental status.
• Thoroughly assess breathing and auscultate.
• Check for wheezing and stridor.
         Signs and Symptoms (1 of 2)
         Si      dS    t
•             g        y,     y
    Sneezing or itchy, runny nose
•   Tightness in chest or throat
•   Irritating, persistent dry cough
•   Hoarseness
•   Rapid, labored, or noisy
    respirations
•   Wheezing and/or stridor
•   Decreased bl d pressure
    D           d blood
•   Increased pulse
•          skin,
    Pale skin dizziness
         Signs and Symptoms (2 of 2)
         Si      dS    t
• Loss of consciousness,  ,   •   Anxietyy
  coma                        •   Abdominal cramps
• Flushing, itching, or       •   Headache
  burning skin                •   Itchy, watery eyes
• Urticaria                   •   Decreasing mental
• S lli
  Swelling                        status
• Warm, tingling feeling in
  the face, mouth, chest,
  feet, hands
            Baseline Vital Signs
            B   li Vit l Si
          p    ,   p        ,       p       ,     ,
• Assess pulse, respirations, blood pressure, skin,
  and pupils.
• Watch for shock.
• Fast pulses and hypotension are ominous signs.
• Skin signs may be unreliable due to rashes or
      lli
  swelling.
            Interventions
            I t     ti
                       q     p p
• Severe reactions require epinephrine and
  ventilatory support.
• Milder reactions may only require oxygen.
• In either case, transport.
                          p                 ,
• A few moments after EpiPen administration, the
  patient is breathing more easily.
• Blood pressure and pulse oximetry values have
  risen; respirations have decreased.
• The paramedics arrive and begin to administer
     fluids
  IV fluids.                  You are the Provider (continued)
                 Detailed Physical Exam




• Consider if:
   – Complaint or history is confusing.
   – There is extended transport time.
   – You need to clarify findings.
• In severe reactions, exam may be omitted.
                 Ongoing Assessment




• Monitor with vigilance; deterioration can be rapid
  and fatal.
• Note the effect of epinephrine. Consider second
  dose.
• If you are unsure whether to administer
  epinephrine, contact medical control.
• Document the patient’s response.
                 p            p
        Emergency M di l Care
        E         Medical C
                 p       g yg ,       prepared to
• In addition to providing oxygen, be p p
  maintain airway or give CPR.
• Placing ice over injury site may slow absorption of
  toxin, but may also freeze skin and cause more
  damage.
• You may or may not be allowed to assist with
  epinephrine depending on local protocols.
• Adult dose is 0.3 mg; p                        g
                       g pediatric dose is 0.15 mg.
           Using an Auto-Injector
           U i      A t I j t
• Receive order from medical
  direction.
• Follow BSI precautions.
  Make        th        i ti
• M k sure the prescription
  is for the patient.
• Make su e t e medication is
    a e sure the ed cat o s
  not discolored or expired.
Auto-Injector
A t I j t
      Administering an Auto-Injector
      Ad i i t i       A t I j t
                  y p
• Remove safety cap.
• Place tip of injector against
  lateral side of patient’s
  thigh.
  thigh
• Push injector firmly and
  hold until all medication is
  injected.
• Remove injector.
                     dose.
• Record time and dose
• Reassess and record vital
  signs.
    g
             Using an AnaKit (1 of 2)
             U i      A Kit
                   p         y
• Follow the same preliminary steps.p
• Prepare injection site.
• Hold syringe upright so that air rises to base of
  needle.
• Turn plunger one quarter turn.
           Using an AnaKit (2 of 2)
           U i      A Kit
                q     y
• Insert needle quickly.
• Push plunger until it stops.
• Have the patient chew and swallow Chlo-Amine
  tablets.
• Apply a cold pack.
                     Review
                     R i

1. The signs and symptoms of an allergic reaction
   are caused by the release of:

A. histamine.
B adrenalin.
B. d      li
C. epinephrine.
D. glucagon.
D glucagon
                      Review
                      R i

Answer: A

Response: The two chief chemicals released by the
  body that result in the signs and symptoms of an
                                       leukotrienes.
  allergic reaction are histamines and leukotrienes
  Epinephrine (Adrenalin) is used to treat allergic
  reactions.
                              Review
                              R i
         g        y                  g                        y
1. The signs and symptoms of an allergic reaction are caused by the
   release of:

A. histamine.
A histamine
Rationale: Correct answer
B. adrenalin.
Rationale: Adrenalin is also called epinephrine and is used to treat
    anaphylaxis along with benedryl.
C. epinephrine.
    p p
Rationale: Epinephrine is used to treat anaphylaxis.
D. glucagon.
Rationale: Glucagon is a hormone produced by the pancreas that
    helps in the control of metabolism.
                         Review
                         R i
                                       p           3y
2. You are called to a local baseball park for a 23-year-
   old man with difficulty breathing. The states that he ate
   a package of peanuts approximately 30 minutes ago,
                                              history.
   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
                              g
   wheezing, even without a stethoscope. You should be
   MOST suspicious of a/an:
A.     t    th      tt k
A acute asthma attack.
B. mild allergic reaction.
C.                  reaction.
C severe allergic reaction
D. moderate allergic reaction.
                        Review
                        R i
Answer: C

Rationale: The patient’s signs and symptoms indicate
  a severe allergic reaction, which is rapidly
  progressing to anaphylactic shock. Signs and
  symptoms of a severe allergic reaction include
  difficulty breathing, urticaria (hives) over large parts
  of the body, and signs of shock (eg, tachycardia,
  hypotension). Certain foods, such as shellfish and
  nuts, may result in a relatively slow onset of
  symptoms,
  symptoms but the symptoms can become just as
  severe.
                          Review (1 of 2)
                          R i
2. You are called to a local baseball park for a 23-year-old man with
    difficulty b   hi    The        h he              k      f
    diffi l breathing. Th states that h 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 H Y can h
    t h        di   d         f          Hg. You             him
                                                        hear hi
    wheezing, even without a stethoscope. You should be MOST
    suspicious of a/an:

A. acute asthma attack.
Rationale: Asthma presents with difficulty breathing, but patients will
    not have urticaria (hives).
B. mild allergic reaction.
                                              urticaria, itching,
Rationale: Mild reactions usually appear with urticaria itching and
    some swelling, but not hypotension and breathing difficulties.
                         Review (2 of 2)
                         R i
2. You are called to a local baseball park for a 23-year-old man with
   difficulty b  hi     The        h he              k      f
   diffi l breathing. Th states that h ate a package of peanuts
   approximately 30 minutes ago, and denies any allergies or past
   medical history. Your assessment reveals widespread urticaria,
   t h        di   d        f           Hg. You
   tachycardia, and a BP of 90/60 mm H Y can h              him
                                                       hear hi
   wheezing, even without a stethoscope. You should be MOST
   suspicious of a/an:

C. severe allergic reaction.
Rationale: Correct answer
D. moderate allergic reaction.
Rationale: The designation is mild or severe — not moderate.
                      Review
                      R i

3. When administering epinephrine by auto injector,
   the EMT-B should hold the injector in place for:

A. 5 seconds.
B 10 seconds.
B.         d
C. 20 seconds.
D.    seconds.
D 30 seconds
                        Review
                        R i

Answer: B

Rationale: When administering epinephrine via auto
  injector, the EMT-B should push the injector firmly
                             activates
  against the thigh until it activates. Hold the injector
  in place for 10 seconds to ensure that all the
  medication is injected.
                           Review
                           R i
                      g                y    j
3. When administering epinephrine by auto injector, the EMT-B
    should hold the injector in place for:

A 5 seconds
A.    seconds.
Rationale: The injector should be held in place for 10 seconds.
B. 10 seconds.
Rationale: Correct answer
C. 20 seconds.
Rationale: The injector should be held in place for 10 seconds.
D. 30 seconds.
Rationale: The injector should be held in place for 10 seconds
                        Review
                        R i
      y   g            p        g g           y p
4. 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. You should:

A. assist him in administering his epinephrine.
B. apply high-flow oxygen via nonrebreathing mask.
    pp y g            yg                     g
C. provide ventilatory assistance with a bag-mask
  device.
D elevate hi l
D. l                   d       him ith          blanket.
         t his legs and cover hi with a warm bl k t
                      Review
                      R i
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-mask device. He clearly
  requires epinephrine, but not before restoring
   d       t b thi first. Regardless of th
  adequate breathing fi t R        dl     f the
  situation, a patient’s airway must be patent and his
  or her breathing must remain adequate at all times.
                  g                   q
                                Review
                                R i
4. 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
                                   injector
    prescribed epinephrine auto injector. You should:

A. assist him in administering his epinephrine.
Rationale: Thi i part of th t t
R ti    l This is                      t but l ft th b thi has
                      t f the treatment, b t only after the breathing h
     been addressed.
B. apply high-flow oxygen via nonrebreathing mask.
Rationale: R
R ti             i ti        d     i t    due to diminished breathing.
        l Respirations need assistance d t di i i h d b thi
C. provide ventilatory assistance with a bag-mask device.
Rationale: Correct answer
D. elevate his legs and cover him with a warm blanket.
Rationale: You should treat for shock, but breathing is the first priority.
                            Review
                            R i
                   g                                   g y
5. You are treating a man who was bitten on the leg by a
   rattlesnake. The patient complains of generalized
   weakness and is diaphoretic. There is a large, swollen area
                                                      wounds.
   on his left lower leg with two obvious puncture wounds In
   addition to high-flow oxygen, appropriate treatment for this
   patient includes:
A.      l i         i l tourniquet and elevating th l
A applying a proximal t        i   t d l        ti the leg.
B. applying ice to the wound to help decrease pain and
   swelling.g
C. encouraging the patient to walk to help decrease venom
   spread.
D splinting th extremity and k
D. li ti the t           it          i      below th l
                               d keeping it b l            l f the
                                                   the level of th
   heart.
                      Review
                      R i

Answer: D

Rationale: Appropriate treatment for a pit viper bite
  includes supplemental oxygen (or assisted
                 needed)
  ventilation if needed), covering the wound with a
  sterile dressing, splinting the affected extremity,
  and keeping the extremity below the level of the
  heart. NEVER apply ice to a snakebite; doing so
  constricts the blood vessels and may only push the
                           bloodstream
  venom further into the bloodstream.
                         Review (1 of 2)
                         R i
                  g                                 g y
5. You are treating a man who was bitten on the leg by a
    rattlesnake. The patient complains of generalized weakness
    and is diaphoretic. There is a large, swollen area on his left
    lower leg with two obvious puncture wounds. In addition to high-
    flow oxygen, appropriate treatment for this patient includes:

A.                                                   leg.
A applying a proximal tourniquet and elevating the leg
Rationale: Tourniquets are not used, but a proximal constricting
    band may be indicated.
B.    l i ice to th        d t h l decrease pain and swelling.
B applying i t the wound to help d               i    d     lli
Rationale: Ice causes vasoconstriction and may push venom into
    the bloodstream.
                          Review (2 of 2)
                          R i
                   g                                g y
5. You are treating a man who was bitten on the leg by a
   rattlesnake. The patient complains of generalized weakness and
   is diaphoretic. There is a large, swollen area on his left lower leg
   with two obvious puncture wounds. In addition to high-flow
   oxygen, appropriate treatment for this patient includes:

C.
C encouraging the patient to walk to help decrease venom spreadspread.
Rationale: Walking only increases the movement of circulation, so
   the patient should be instructed to remain seated or lying down.
D. li ti the t         it    d keeping it b l
D splinting th extremity and k      i           the level of th h t
                                          below th l    l f the heart.
Rationale: Correct answer
                      Review
                      R i
6 pp            y      y               g
6. Approximately 3 days after removing a tick from his
   leg, a 35-year-old man presents with a local rash
   that resembles a “bulls-eye.” His BP is 110/68 mm
   Hg pulse is 100 beats/min and respirations are 22
   Hg,              beats/min,
   breaths/min with adequate air exchange. The
   MOST likely cause of this patient’s symptoms is:
              y              p          y p

A. Lyme disease.
B. an allergic reaction.
C. a systemic infection.
D. Rocky mountain spotted fever.
                      Review
                      R i

Answer: A

Rationale: Lyme disease, which is transmitted by an
  infected tick, presents approximately 2 to 3 days
        exposure,
  after exposure and includes a rash that appears to
  have a “bulls-eye” in the center. Within a few more
  days (in some cases, up to a week), the patient
  typically begins experiencing joint pain—especially
  in the knees.
                               Review
                               R i
6. Approximately 3 days after removing a tick from his leg, a 35-year-old
    man presents with a local rash that resembles a “bulls-eye.” His BP
    is              Hg, l is       beats/min, d         i ti
    i 110/68 mm H pulse i 100 b t / i and respirations are 22
    breaths/min with adequate air exchange. The MOST likely cause of
    this patient’s symptoms is:

A. Lyme disease.
Rationale: Correct answer
   a allergic eact o
B. an a e g c reaction.
Rationale: An allergic reaction presents with urticaria (hives), itching,
     and tenderness.
C. a systemic infection.
Rationale: A systemic infection presents with redness, swelling, and
     warm or hot skin at bite site.
D. Rocky mountain spotted fever.
R ti    l Rocky          t i      tt d f  i         d by tick bite,
Rationale: R k mountain spotted fever is caused b a ti k bit
     symptoms are fever, nausea, vomiting, headache, and muscle pain.
                       Review
                       R i

7. You are treating a woman who was stung
   numerous times by hornets. On assessment, you
   note that some of the stingers are still imbedded in
   her skin. You should:

A. leave the stingers in place.
B. scrape the stingers from her skin.
        p          g
C. pull the stingers out with tweezers.
D. cover the stings with tight dressings.
                       Review
                       R i

Answer: B

Rationale: Because of the venom left in the sac
  located at the end of the stinger, you should not
                                             them.
  grab the stingers in an attempt to remove them
  Instead, scrape them off with a rigid object such as
  a credit card.
                           Review
                           R i
7. You are treating a woman who was stung numerous times by
    hornets. On assessment, you note that some of the stingers are
    still imbedded in her skin. You should:

A. leave the stingers in place.
Rationale: A stinger will continue to inject venom even when the
    stinger is no longer attached to the insect.
B. scrape the stingers from her skin.
Rationale: Correct answer
C. pull the stingers out with tweezers.
   p            g
Rationale: Using tweezers may squeeze more venom into the
    patient.
                  g        g           g
D. cover the stings with tight dressings.
Rationale: Remove the stingers — do not leave them in place.
                      Review
                      R i

8. The adult epinephrine auto-injector delivers _____
   mg of a _________ solution via the
                    route.
   ______________ route

A. 0.15, 1:2,000,
A 0 15 1:2 000 subcutaneous
B. 0.3, 1:1,000, intramuscular
C. 0.15, 1:2,000, subcutaneous
D. 0.3, 1:2,000, intramuscular
                      Review
                      R i

Answer: B

Rationale: The adult epinephrine auto-injector deliver
  0.3 mg of a 1:1,000 solution via the intramuscular
  route The pediatric auto-injector delivers 0 15 mg
  route.                                     0.15
  of a 1:2,000 via the same route. The EMT-B should
  be thoroughly familiar with the dose and
  administration route for any drug he or she gives or
  assists the patient with.
                            Review
                            R i
8. The adult epinephrine auto-injector delivers _____ mg of a
    _________ solution via the ______________ route.

A. 0.15, 1:2,000, subcutaneous
Rationale: This is a pediatric dose, but it is not delivered
    subcutaneously.
B. 0.3, 1:1,000, intramuscular
Rationale: Correct answer
C. 0.15, 1:2,000, subcutaneous
Rationale: This is a pediatric dose, but it is not delivered
    subcutaneously.
D. 0.3, 1:2,000, intramuscular
                                                        (mg)
Rationale: This is the correct number of milligrams (mg), but it is
    the incorrect solution, it should be 1:1000.
                        Review
                        R i

9. The negative affects associated with anaphylactic
   shock are the result of:

A. severe internal fluid loss.
B. inadequate pumping of th h t
B i d        t        i    f the heart.
C. vasodilation and bronchoconstriction.
D.              system’s              adrenalin.
D the nervous system s release of adrenalin
                      Review
                      R i

Answer: C

Rationale: Anaphylactic shock is associated with two
  negative effects: breathing impairment and
  hypotension These effects are the result of
  hypotension.
  bronchoconstriction and vasodilation in response to
  a massive release of histamines and leukotrienes
  from the immune system.
                             Review
                             R i
          g                                  y
9. The negative affects associated with anaphylactic shock are the
    result of:

A.                       loss.
A severe internal fluid loss
Rationale: The body does not lose fluid; blood pools in the dilated
    circulatory system and causes less blood flow back to the heart.
B inadequate pumping of th h t
B. i d       t       i    f the heart.
Rationale: Inadequate pumping is not the problem; the cardiac output
    is deceased due to poor return back to the heart.
C. vasodilation and bronchoconstriction.
Rationale: Correct answer
D.              system s             adrenalin.
D the nervous system’s release of adrenalin
Rationale: Adrenalin is the treatment for anaphylaxis.
                      Review
                      R i

10. The MOST reliable indicator of upper airway
  swelling during a severe allergic reaction is:

A. stridor.
B anxiety.
B.      i t
C. cyanosis.
D. wheezing.
D wheezing
                       Review
                       R i

Answer: A

Rationale: Stridor is a high-pitched sound that is most
  often heard during inhalation. It indicates swelling
                airway. Wheezing,              sound,
  of the upper airway Wheezing a whistling sound
  is caused by narrowed bronchioles; it indicates
  narrowing or swelling of the lower airway. Anxiety
  and cyanosis can occur from a variety of causes;
  they are not exclusive to airway swelling.
                             Review
                             R i
                                              y        g      g
10. The MOST reliable indicator of upper airway swelling during a
    severe allergic reaction is:

A. stridor.
A stridor
Rationale: Correct answer
B. anxiety.
Rationale: This is typically a symptom of hypoxia or decreased
    oxygenation to the brain.
C. cyanosis.
    y
Rationale: This is a sign of hypoxia and inadequate tissue perfusion.
D. wheezing.
                                                          narrowing.
Rationale: This is a sign of lower airway constriction or narrowing

				
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