Emergency Field Medicine: Anaphylaxis

Unit 4: Emergency Medicine

Objectives of Emergency Field Medicine

• Identify relationships between basic facts and general principles in emergency field medicine.
• Identify relationships between basic facts and general principles for managing victims of violent crimes.
• Determine step-by-step procedures for managing obstetrical emergencies.

Overview of Topics

• Management of Environmental Emergencies covered
• Venomous Stings/Bites and Poisonous Plants listed
• Management of victims of violent crimes
• Management of victims of sexual assault
• Management of Obstetrical Emergencies

Anaphylaxis

• Anaphylaxis relates to topics of venous stings, bites and poisonous plants in the overview
• Anaphylaxis is an acute, potentially life-threatening allergic reaction.
• Immunoglobulin E (IgE) mediates anaphylactic reactions
• Anaphylaxis happens in previously sensitized people when re-exposed to a sensitizing antigen.
• Common triggers: drugs like beta-lactam antibiotics and insulin.
• Common triggers: foods like nuts, eggs, and seafood.
• Common triggers: proteins like tetanus antitoxin and blood transfusions
• Common triggers: animal venoms and latex.
• The identification of a trigger is helpful, but, treatment should not be delayed to obtain a history.
• Symptoms often begin within 15 minutes of exposure involving skin, upper/lower airways, cardiovascular system or the GI tract.
• Progression can be rapid, leading to shock and potential death.
• Skin signs and symptoms consist of pruritus, urticaria, cyanosis, angioedema, and flushing.
• Cardiac signs and symptoms consist of palpitations
• EENT signs and symptoms consist of sneezing, rhinorrhea, and swelling of the face, lips, and eyes
• Respiratory system signs and symptoms consist of dyspnea, choking sensation, stridor, wheezing, hoarseness, bronchospasms, and cough.
• GI signs and symptoms consist of abdominal cramps, diarrhea, nausea, and vomiting.
• CNS signs and symptoms consist of dizziness and seizures.
• VS signs and symptoms consist of hypotension, tachycardia, and shock;
• Treatment of anaphylaxis is immediate transport/EVAC unless emergent treatment is indicated
• Prepare for ALS intervention, administer oxygen as well as, possible intubation and isotonic fluids

Medications for Treatment of Anaphylaxis

• Give epinephrine promptly subcutaneous, intramuscular or intravenous epinephrine, is a cornerstone in treating anaphylaxis;
• Intramuscular administration of 0.3 to 0.5mg using a 1:1,000 solution in the mid-outer thigh, can be repeated every 5-15 minutes
• Intravenous administration using 1:10,000 solution if intramuscular is inadequate
• Albuterol is usable if for a bronchospasm resistant to epinephrine
• Nebulizer or metered dose inhaler can administer 2.5 to 5mg in 3mL saline
• Antihistamines, IV H1 blockers like Diphenhydramine
• Consider H2 blockers such as Famotidine
• Corticosteroids, IV 125mg methylprednisolone

Environmental Stressors

• Exposure to environmental stressors in the field affect the body through heat gain and loss
• Conductive heat impacts ground, rocks, water, and direction of heat flow is from higher to lower temperature.
• Convective facilitates conductive heat exchange by molecules moving  in gas or liquid form.
• Convective causes rapid heat loss as warmed molecules are pushed away, such as with a fan or wind.
• Radiative heat happens because energy is transmitted away in absence of objects for example a light bulb or fire
• Evaporative heat loss happens from moisture on skin surface, this carrying warmed molecules from the body.
• Evaporative heat loss is a combination of conduction and convection.
• Sweating, wet skin exposed to wind, and exhalation/inhalation during respiration all relate to evaporative loss.

Heat And Cold Injuries

• Accidental hypothermia relates to heat and cold injuries
• Accidental Hypothermia is described as an unintentional normal core temperature decrease by 3.6°F
• Accidental Hypothermia is a core temperature below 95°F.
• Pathology impacts the nervous system, cardiovascular system, and respiratory system.
• Pathology impacts also renal system leading to clinical presentation
• Can be any combination of the above, as well as obtain details from medical history
• Treatment consists of removing wet clothing, keep patient horizontal and do not allow exertion or massage extremities, stabilize injuries/wounds then heated IV fluids
• Treatment consists of heated humidified oxygen, water bottles in groin and axillae,wrap in warm clothes, bedding emergency blanket

Immersion in Cold Water

• Hypothermia results when immersed in water with a T< 91.4° F
• A significant risk occurs in temperatures below 77° F
• Physiological responses involve if head is above water in phase 1: the 0-2 minutes of cold shock
• Rapid onset within minutes can cause immediate death if not able to stay afloat
• Phase 1 may lead to aspiration and drawing due to gasp reflex and inability to breath-hold
• Hyperventilation, tachycardia and peripheral vasoconstriction
• Phase 2 occurs from 5-15 minutes with cold incapacitation involving motor skills
• Peripheral tissues get significant cooling, decreasing coordination, making survival survival impossible
• Phase 3 occurs after thirty mins, you could be one,set to a hypothermia. it shows the same signs as accidental hypothermia and possible to survive for up to an hour if head above water
• Phase 4 involves circum rescue collapse with Shock after rescue with possible cardiac arrest
• If not circumcised use same guidelines as accidental hypothermia

Trench Foot information

• Trench Foot pathology caused by prolonged cold exposure, restricted circulation
• Trench Foot causes injury to vessels, skin, nerves, and muscles;
• Clinical findings during cold exposure include bright red skin then pale as well as maceration of the skin

Prehyperemic Phase Details of Trench Foot

• Occurs when removed and prior to rewarming and may last hours to days
• Extremities become yellowish-white mottle or pale blue
• Walking is difficult since Extremities continue to feel cold and numb;
• Peripheral pulse initially thready then delayed cap refill Hyperemic phase results in increased blood flow beginning abruptly, lasting weeks: 

Hyperemic Phase Details of Trench Foot

• Affected are hot, erythematous, painful and edematous. 
• Pulses are Full and bounding with delayed cap refill and Intense burning, throbbing, shooting pain
• Throbbing/burning progress after 24-36 hours, where shooting/stabbing occurs. Proprioception retained
• Edema and blisters may slough with pink dermis indicating gangrene
• Post-hyperemic phase occurs over weeks/years - even permanent
• there may be no obvious physical signs that recur and dull aches and anesthesia

Focused History Details of Trench Foot

• Assess for concurrent and Gather relevant information to not delay treatment
• Once re-freezing is eliminated, raise the temp if needed, cool extremities by exposing steadily from a fan
• Continue local cooling, avoid nicotine and keep injuries alleviated

Defining Frostbite

• A true freezing injury where ice crystals tend to form in deep or shallow tissues
• Clinical presentation: coldness, numbness with appearance of yellowish white color
• Intense vasoconstriction occurs Ischemia involved extremity perceive clumsy or patient has extreme pain
• Throbbing begins 2-3 days after rewarming and can last for a variable time frame .
• Ischemic neuritis begins after 1wk this can also be felt as tingling
• Some patients may have burning or electric current sensations about 2 days after the injury and lasting for about 6 weeks
• All patients affected by a frostbite injury experience some degree sensory loss, and focused history can affect the extent. You can assess this concurrent to trench for you and address conditions of exposure.

Treatment For Frostbite

• Is to get and remove the clothing and attempt removal after you have made the effort the re-warm if possible.
• The attempt of re-warming can be done by placing warm fluids or companion's bodies to keep at a max of 10 minutes. And if swelling is to occur and the wound can removed use a dose of NSAIDs to help. However, you do not apply heat and instead let it recover naturally

Types of Heat Cramps

• Heat Cramps are a series of painful skeletal that muscles or occur during the activity of exercising of large parts of the body within an area. Assess for any signs and symptoms leading up to the injury
• The treatment requires rest, replacement of electrolytes with avoidance of table salt.

Heat Rash

• Heat Rash aka miliaria rubra, prickly heat, sweat rash relates to heat cramp
• Blocked sweat glands from build up cause reactions such as redness and blister like lesions
• Ensure the area is not sweating frequently, use topical corticosteroids, as well as antihistamine and be mindful of the current status

Heat Exhaustion facts

• Heat Exhaustion Mild to moderate heat illness associated with core body temperatures from 101.3° to 104.0°F
• Can develop acutely in athletes in heat which reduces the body
• Fatigue is also a symptom with related dizziness and headache along with some confusion but otherwise there is no other major abnormalities to expect

Heatstroke

• A life-threatening condition with core body temperature above 104.0°F
• Sweat-soaked and pale skin is classic, with older adults being more dry
• Use caution with patients with Delirium or agitation that gets to the point of combativeness including the presence of stupor, seizures, coma Ensure open airway when treating, actively cooling with immersion cold or ice water. Monitor for hypothermia Temperature decreases below 102 °F so maintain heat levels to avoid toxicity.

Sunburns

• Sunburn caused by overexposure to ultraviolet radiation in variable time or high intense light
• UVR include UVA, UVB, UVC with UVC being blocked, UVB being an epidermis and dermis reflection, UVA reaching the dermis with cell inflictate
• To treat these provide symptomatic relief

Altitude Sickness

• Altitude Sickness is a range 4,921 to 18,045ft where hypoxic tolerance is reduced. This occurs through barometric pressure
• Acute Cerebral Hypoxia can occur when ascent is too rapid, resulting in sleepiness, vertigo, dizziness, and hallucinations.
• High Altitude Headache has often anorexia, nausea and symptoms due to the same acute sickness. Give O2

Acute Mountain Sickness Details

• It has similar symptoms to influenza, hangover, exhaustion so evaluate altitude attained, and headache to fatigue
• Then consider and evaluate with a focused history of ascent and rate. Then descend then Low flow Oxygen Acetaminophen, NSAIDs, Zofran may then be given to help

Concerns with High Atittudes

• High Altitude Cerebral Edema (HACE) is a deadly illness that has Altered LOC, onset to the heart. Ensure symptoms are ataxic gait, impaired mentation, confusion, drowsiness/ stupor.
• At first HACE highest priority is descent and Dexamethasone
• High Altitude Pulmonary Edema (HAPE) has multiple phases that can include Dyspnea and/or is severe

Barotrauma

• Barotrauma occurs in Pressure Related Injuries due to equilibrium Gas, or air in lungs can lead to Air embolism,
• Follow guidelines based on pulmonary injuries

Pressure Injuries

• Pressure injuries are from the body not being able to equilibrate and so the Barotrauma injuries are the effect These usually come from blocked areas in the body:
• Middle Ear; usually affects the blockage due. In this case, to address you could use decongestants as well topicals
• Sinuses can result due to front sinuses are commonly affected. Address using dives, with a history, and manage topically. The use of topical decongestants has been shown to have a positive on the patient's experience
• For the Gastrointestinal or the the Airways the management is from the expansion where lung injuries can be lethal. If so treat them

Arthropod Venom and Response

• Poisons, venoms, and toxins from various sources can cause three responses
• Neurotoxic, which affects the peripheral or central nervous systems.
• Hemotoxic is by breaking down red blood cells, local tissues, therefore, disrupts the cardiovascular function, or cytotoxic by cellular destruction through any of those tissues it comes intact by.
• With various plants, ensure the toxins is regardless since it can trigger anaphylactic

Details about Pit Vipers

• Pit Vipers inject thermal receptor venom organs between the eyes that are neuroxic and inhibits
• These Vipers are able to provide side effects that lead to weakness dizziness,
• Provide patient care by keeping the location clean to reduce the severity

Details about Venomous Lizard

• Venomous Lizard lower teeth inject venom non neural, however, to detach the lizard you must apply something
• To provide patient care you have to maintain to remove any and all material

Arthropods have various ways to sting and inject the venom, to note and manage

• Beest have a very hard venom than can lead to death even by 50
• Wasps are generally less than honey bees, so take care to clean the area

Centiped or Millipedes

• Centipedes or Millipedes the former contain hooks while the latter is primarily acid contact and the main
• Centiped or Millipedes requires heat and pain where in the middle the most important aspect has been to try the use of water to clean the area
• Various spiders including recluse and widow*
• Spider venom comes from its fangs and has various compositions and potency
• Tarantulas and Baboon** Spiders produce neurotoxicity and skeletal muscle destruction in rodents
• Treat this with supportive care, and cleaning
• Treatment With Scorpions or Similar*
• With Scorpion venom, it needs to be for any heart or pulmonary systems. Consider the location of the symptoms. Then use anti toxicity as needed. This will include a focus on
• For marine life you would use a warm, clean or distilled water source to keep the area clean as well removing debris. It is common to find yourself using it to help keep the water, you must. Do you provide some pain relief.

Conclusion

• Unit 4 Emergency Medicine focused on Management of Environmental Emergencies with various envenom and plant life injuries