chapter 33: environmental emergencies

how does physical condition affect exposure?

• pts who are ill or in poor physical condition cannot tolerate extreme temps as well as people whose cardiovascular, metabolic, and nervous systems are functioning well

• exertion also plays a role [brisk walk generates body heat when it is both cold and hot]

how does age affect exposure?

• children and older adults are more likely to experience temp-related illness

• infants have poot thermoregulation at birth → cannot shiver and generate heat until about 12-18 months

  • infant’s surface-area-to-mass radio is larger than an adults, so they heat up and cool down faster

• older adults lose subcutaneous tissues as they age, reducing the amount of insulation they have

  • poor circulation → contribute to increased heat loss

  • medications → can affect older person’s body thermostat

  • lying immobile on hot or cold surface after a fall → can rapidly lead to overexpsure

how does nutrition and hydration affect exposure?

• calories are required for metabolism function

  • calories provide fuel to burn, creating heat during the cold, and water provides sweat for evaporation and removing heat

• good hydration provides water as a catalyst for much of this metabolism

• lack of food or water will aggravate both hot and cold stress

• alcohol use can include fluid loss and increase risk for temp-related injuries

how do environmental conditions affect exposure?

• air temperature, humidity level, and wind can complicate or improve environmental situations

• extremes in temperature and humidity are not needed to rpoduce hot or cold injuries

  • hypothermia often occurs at temps between 30-50 degrees

  • heatstroke often occurs when temp is 80 degrees and humidity is 80%

• when evaluating pt condition, consider environment and whether the pt is prepared for that situation

what is conduction, convection, evaporation, radiation, and respiration and how do they lead to heat loss?

• conduction: transfer of heat from a part of the body to a colder object or substance via direct contact

  • heat can also be gained if object/substance is warm

• convection: occurs when heat is transferred to circulating air, such as when cool air moves across the body surface

  • heat can be gained if air moving across person’s body is hotter than temp of the environment, like in industrial settings

• evaporation: conversion of any liquid to a gas, a process that requires energy [heat]

  • natural mechanism by which sweating cools the body

• radiation: transfer of heat by radiant energy, which is a type of invisible light

  • causes heat loss, such as when a person stands in a cold room

  • heat can also be gained by radiation, like when standing by a fire

• respiration: causes body heat loss as warm air in the lungs is exhaled and cooler air in inhaled

what are the 3 ways the rate and amount of heat loss or gain can be modified?

1. increase or decrease heat production

   • shiver or increase movement to increase heat production

   • reduce level of activity to reduce heat production

2. move to an area where heat loss is decreased or increased

   • move out of a cold environment and seek shelter from wind to decrease heat loss

   • move into shade can decrease heat production by reducing ambient temp by 10 degrees or more

     • if pt cannot be moved, create shade and fan the pt

3. wear appropriate clothing for the environment

   • wear layers of insulated clothing [wool, down, synthetics] in cold environments

     • protective clothing traps perspiration and prevents evaporation

     • cover head, hands and feet and remove wet clothing

   • wear lightweight, loose fitting clothing in hot environments

what is hypothermia? how does the body protect itself against heat loss? what happens as cold exposure worsens? what populations is hypothermia most common among?

• hypothermia: occurs when body’s core temperature falls below 95°F

• to protect against heat loss, the body:

  • constricts blood vessels in the skin → blue lips and/or fingertips

  • shivers create additional heat

• as cold exposure worsens and these mechanisms are overwhelmed, body functions slow and mental status deteriorates

• most common among:

  • geriatric, pediatric, and ill people who are less able to adjust to temp extremes

  • pts with illness or injuries, such as burns, shock, head injury, stroke, generalized infection, spinal cord injuries, diabetes, and hypoglycemia

  • pts who have taken certain drugs or consumed alcohol

what is mild hypothermia and what are the signs and symptoms? what is moderate hypothermia and what are the signs and symptoms? what is severe hypothermia and what are the signs and symptoms?

• mild hypothermia: core temp is between 90°F and 95°F

  • pt is alert and shivering in an attempt to gain head

  • HR and RR are usually rapid

  • light-skinned people can be red, but may eventually appear pale, then blue due to constriction of blood vessels

• moderate hypothermia: core temp is between 86°F and 93.2°F

  • when core temp is less than 90°F, shivering stops and muscular activity decreases

    • at first, fine muscle activity ceases, then all muscle activity stops and mental status deteriorates

• severe hypothermia: core temp is below 86°F

  • shivering stops, muscular activity decreases then stops, and mental status deteriorates

what happens as core temp drops below 85°F? what about when core tempts drop below 80°F? what about when core temp hits 80°F?

• as core temp drops towards 85°F:

  • pt becomes lethargic and stops fighting the cold

  • LOC decreases, and pt may try to remove their clothes

  • pt experiences poor coordination and memory loss, along with reduced or complete loss of touch, mood changes, impaired judgement

  • pt becomes less communicative, experiences joint or muscle stiffness, and has trouble speaking

  • pt begins to appear appears rigid or stiff

• as core temp drops below 80°F:

  • all cardiorespiratory activtiy may cease

  • pupillary reaction will slow

  • pt may appear dead

    • never assume a cold, pulseless pt is dead

    • pts can survive severe hypothermia with emergency care

• if core temp continues to fall to 80°F:

  • vital signs slow

  • pulse becomes slower and weaker

  • respirations become shallow or absent

  • cardiac dysrhythmias may occur as BP decreases

how do you assess if a pt in severe hypothermia is truly dead?

• perform an extended pulse check [up to a full minute[

• assess at the carotid or femoral pulse

• remember: pt in cardiac arrest from hypothermia should not considered dead until aggressive rewarming has been attempted alongside resuscitation

what is frostnip? what is immersion foot? how does the skin present in both frostnip and immersion foot?

• frostnip: occurs after prolonged exposure to the cold, when skin may freeze but the deeper tissues are unaffected

  • because frostnip is usually painless, the pt often is uanware that a cold injury has occurred

• immersion foot [trench foot]: occurs after prolonged exposure to cold water

• in both frostnip and immersion foot, skin is pale and cold to the otuch; normal color does not return after palpation of the skin

  • skin of foot will be wrinkled, but it can also remain soft

  • pt will report loss of feeling and sensation in injured area

what is frostbite? how do ice crystals affect the cells? how does change in water content affect the cells? what happens when the ice inside the cells thaw? what occurs during less severe damage?

• frostbite: most serious local cold injury, as tissues are actually frozen, permanently damaging cells

  • presence of ice crystals within the cells may cause physical damage

  • change in the water content in the cells may also cause changes in the concentration of critical electrolytes, permanently changing cell chemistry

• when ice thaws, further chemical changes occur, causing permanent damage or cell death [necrosis or gangrene]

  • if gangrene occurs, the dead tissue must be surgically removes, sometimes by amputation

• less severe damage results in exposed part becoming inflamed, tender to touch, and unable to tolerate cold exposure

how can frostbite be identified? how does frostbite present itself? what is the difference in skin damage ebtween superifical and deep frostbite?

• frostbite can be identified by the hard, waxy feel of affected tissues

  • injured part has a firm to frozen feeling upon touch

  • if only skin deep, skin will feel leather or thick instead of hard

  • blisters and swelling may be present

  • in light-skinned people with deep injury that has thawed or partially thawed, the skin may appear red or white, or mottled and cyanotic

• depth of skin damage will vary

  • superficial frostbite → only skin is frozen

  • deep frostbite → deeper tissues are frozen

• sometimes, you may not be able to tell superficial from deep frostbite

what should you determine and investigate when responding to a pt with frostbite?

• determine:

  • duration of exposure

  • temp to which the body part was exposed

  • wind velocity during exposure

• investigate:

  • exposure to wet conditions

  • inadequate insulation from cold or wing

  • restricted circulation from tight clothign or shoes or circulatory disease

  • fatigure

  • poor nutrition

  • alcohol/drug abuse

  • hypothermia

  • diabetes

  • cardiovascular disease

  • age

how to conduct a scene size up for a potential cold injury?

• note environmental conditions:

  • air temp

  • wind chill

  • wet or dry

• ensure scene is safe

• identify potential safety hazards like wet grass, mud, or icy streets

• cold environments may present special challenges for you and your pt, so consider special hazards such as avalanches

• summon additional help, like search and rescue, asap

• look for MOI indicators

how to conduct a primary assessment of cold injuries?

• perform rapid exam to look for and treat life threats

• if CC is feeling cold, assess core temp by placing back of hand on abdomen

• evaluate LOC using AVPU → if altered, indication of cold injury

• consider spinal immobilization based on scene size-up and CC

• if cardiac arrest if suspected, provide high-quality chest compressions, then address airway and breathing after

• if breathing is slow or shallow, ventilation with bag mask may be necessary

  • use warmed and humidified oxygen if available

• if radial pulse is absent, palpate for a carotid pulse and wait for up to 60 seconds before deciding pt is pulseless

• assume shock is present and treat accordingly

• bleeding may be difficult to find due to slow circulation and thick clotting

• all pts with hypothermia require rapid transport for evaluation and treatment

• handle pt for transport quickly, safely, and gently

  • rough handling can cause a cold, slow, weak heart to fibrillate

• if transport is delayed, protect pt from further heat loss

how to history take a pt with a cold injury?

• investigate CC

• obtain medical history and be alert for injury-specific signs and symptoms, as well as any pertinent negatives

• find out how long pt was exposed to cold environment

• figure out any meds taken and any underlying medical conditions, as they can have an impact on the way cold affects pt’s metabolism

• figure out pt’s last oral intake and activity prior to exposure to determine severity

how to conduct a secondary assessment on a pt with a cold injury?

• focus physical exam on severity of hypothermia, assessing areas directly affected by cold exposure, and the degree of damage

  • + determine any other injuries/conditions that were not initially found

• do a careful examination of pt’s entire body

• vital signs can be altered by hypothermia and can indicate severity

  • RR may be slow and shallow → low oxygen in the body

  • low BP and slow HR → moderate to severe hypothermia

  • changes in mental status should be evaluated with AVPU

  • determine core body temp with hypothermia thermometer

  • pulse oximetry will be inaccurate due to lack of perfusion in extremities

how to conduct reassessment of a cold injury?

• reassess vitals and CC

• identify and treat changes in pt’s condition

• keep a close eye on LOC and vitals

• as body rewarms, sudden redistribution of fluids and release of built-up chemicals can have harmful effects, including cardiac dysrhythmias

• be vigilant even if pt’s condition appears to improve

• review all treatments that have been performed

• reassess oxygen delivery and continue to provide for a warm environment by removing wet or frozen clothing

  • do not remove if clothing is frozen TO pt’s skin

• communicate all info you have gathered to receiving facility

• when documenting, include:

  • pt’s physical status

  • conditions of scene

  • info gathered from bystanders

  • changes in pt’s mental status during treatment and transport

what is general management protocol for cold emergencies?

• to prevent damage to feet, do not allow pt to walk

• remove wet clothing and place dry blankets over and under the pt

• give pt warm, humidified oxygen if available

• do not roughly handle pt with moderate-severe hypothermia, as it may cause ventricular fibrillation, which may not respond to defibrillation

• do not massage extremities

• do not allow pt to eat or use any stimulants [coffee, tea, soda, or tobacco] as they are vasoconstrictors and can further impair circulation

what are the defining factors of mild hypothermia? how should you treat it?

• mild hypothermia: pt is alert, shivering, responds appropriately, and core body temp is between 90°F-95°F

• treatment:

  • begin passive rewarming slowly → place pt in warm environment, remove wet clothing, and apply heat packs to groin, axillary, and cervical regions

  • turn heat up high in pt compartment of ambulance

  • do not place heat racks directly on skin

  • if allowed by local protocols, give warm fluids by mouth, assuming pt is alert and can swallow without difficulty

how should you treat moderate to severe hypothermia?

• active rewarming is best accomplished in ED

  • warm IVs, lavage with warm fluids, and rewarding blood outside body before reintroducing it [extracorporeal rewarming]

  • rewarming pt too quickly may cause fatal cardiac dysrhythmia or other significant complications → why local protocols dictate appropriate rewarming methods based on core body temps

• your goal is to prevent further heat loss, so:

  • remove pt from cold environment

  • place pt in the ambulance, remove wet clothing, cover pt with blankets, and transport

what is the general emergency treatment of local cold injuries in the field?

• remove pt from further exposure to the cold

• handle injured part gently and protect it from further injury

• remove any wet or restricting clothing from pt, especially over the injured part

how do you treat frostnip and immersion foot?

• frostnip treatment should include:

  • contact with a warm object [may be all that the pt needs]

  • usage of your hand or the pt’s own body for heat gain

  • a tingling or reddening of the skin in light-skinned people

• immersion foot treatment should include:

  • removal of wet shoes, boots, socks, and gradual rewarming of the foot

  • splinting the extremity, covering it loosely with a dry, sterile dressing

  • NO rubbing or massaging of the injured tissues

  • NO re-exposure to the cold

how do you treat a late/deep cold injury?

• remove any jewelry from injured part and cover the injury loosely with a dry, sterile dressing

  • do not break blisters or rub or massage the area

  • do not apply heat or reward the part [this should be done in the ED]

• do not allow the pt to stand or walk on a frostbitten foot

• evaluate the pt’s general condition for the signs or symptoms of systemic hypothermia

• support vital functions as necessary and provide rapid transport

• if hospital care is unavailable and medical control instructs you to rewarm:

  • immerse frostbitten part in water with a temp between 102°F-104°F

  • check water temp with thermometer before immersing the limb and recheck frequently during rewarming

  • make sure water temp never exceeds 105°F

  • keep frostbitten part in water until it feels warm and sensation returns

• expect pt to report severe pain

• cover frostbitten part with soft, padded, sterile cotton dressings

what is hyperthermia? what are the 2 most efficient ways to decrease heat? what two things can reduce heat loss? what are risk factors for hyperthermia? what are the 3 forms of heat emergency? who is at greatest risk?

• hyperthermia: high core temp, usually 101°F or higher

• two most efficient ways to decrease heat:

  • sweating [and evaporation of the sweat

  • dilation of skin blood vessels

• high air temp can reduce heat loss by radiation

• high humidity reduces heat loss through evaporation

• risk factors:

  • inability to acclimate

  • vigorous exercise, causing loss of fluid and electrolytes

• 3 forms of heat emergency [which can all be present in same pt]

  • heat cramps

  • heat exhaustion

  • heat stroke

• pts at greatest risk for heat emergencies:

  • children

  • geriatric pts

  • pts with heart disease, COPD, diabetes, dehydration, and obesity

  • pts with limited mobility

• alcohol and certain drugs dehydrate the body or decrease sweat production

what are heat cramps and where do they normally occur? what is the cause(s) of heat cramps? when should you suspect heat cramps?

• heat cramps: painful muscle spasms that occur after vigorous exercise

  • usually occurs in leg or abdominal muscles

  • when abdominal muscles are involved, pain and muscle spasm may be so severe pt appears to have an acute abdominal condition

• exact cause is not well understood, but pay possibly be due to:

  • sweat produced during strenuous exercise causes a change in body’s electrolyte balance

  • dehydration

• if a pt with sudden onset of abdominal cramps has been exercising vigorously in a hot environment, suspect heat cramps

what is heat exhaustion and what is it caused by? who is particularly at risk? what are the signs and symptoms?

• heat exhaustion [heat prostration, heat collapse]: hypovolemia as the result of the loss of water and electrolytes from heavy sweating

  • most common heat emergency

  • commonly caused by heat exposure, stress, and fatigue

• people who work/exercise vigorously and those who wear heavy clothing in warm, humid, or poorly ventilated environments are particularly prone to heat exhaustion

• signs and symptoms:

  • dizziness, weakness, or syncope indicating change in LOC with accompanying nausea, vomiting, or headache

  • muscle cramping

  • onset while working vigorously or exercising in hot, humid, or poorly ventilated environments, or extended time in hot, humid environments

  • onset at rest due to lack of acclimation to environment

  • cold, clammy skin with ashen pallor

  • dry tongue and thirst

  • normal vitals, though HR is usually rapid and weak and diastolic BP may be low

  • normal or slightly elevated body temp; onr are occasions, as high as 104°F

what is heat stroke? who is the most at risk for developing heat stroke? how do pts present? what are the signs of heat stroke as it progresses?

• heatstroke: occurs when body is subjected to more heat than it can handle and normal mechanisms for getting rid of the excess heat are overwhelmed

  • body temp rises rapidly to the level at which tissues are destroyed

  • least common but most serious heat emergency

• heatstroke can develop in:

  • pts during vigorous physical activity, or when they are outdoors or in a closed, poorly ventilated, humid space

  • people [particularly geriatric pts] experiencing heat waves while living in buildings with no air conditioning or with poor ventilation

  • children left unattended in a locked vehicle on a hot day

• pts often have hot, dry, flushed skin from overwhelming their sweating mechanism → can have heat stroke even if they are still sweating

• body temp can rise to 106°F or more

• as core temp rises, LOC decreases, resulting in unconsciousness

  • first sign if often change in behavior

  • pt quickly becomes unresponsive and seizures may occur

  • pulse is unusually strong and rapid, then becomes weaker as BP falls

  • RR increases as body attempts to compensate

how to conduct scene size up for heat emergencies?

• perform environment assessment, as heat emergency may be secondary

• if pt is unconscious, has altered LOC, or requires IV fluids to treat shock, call for ALS assistance

• look for MOI indicators

• cooling prior to transport is indicated if facilities are available

  • if pt is palced in a cold-water immersion bath, monitor the pt and assist as necessary

    • do not remove until temp has normalized to a level between 101°F and 102°F

    • do not overcool the pt → can lead to shivering

• closely monitor pt

• protect yourself from heat and stay hydrated

• long-sleeved shirts and long pants may be uncomfortable, but they can help protect from blood or bodily fluid splashes

how to conduct primary assessment for heat emergencies?

• observe how pt interacts with you and the environment

• ask about CC

• perform rapid scan and avoid tunnel vision

• assess mental status using AVPU

• assess ABCs and treat any life threats

• if pt is unresponsive,

  • be cautious of how you open the airway

  • consider spinal immobilization if trauma possible

  • insert airway and provide bag-mask ventilations

• if circulation is adequate, assess for perfusion and bleeding

• assess skin condition carefully

  • moist, pale, cool skin → excessive fluid and salt loss

  • hot, dry skin or hot, moist skin → body cannot regulate core temp

• treat aggressively for shock by removing pt from heat and position pt to improvide circulation

• if there are signs of heatstroke, provide rapid transport

how to history take for heat emergencies?

• investigate CC

• obtain SAMPLE

  • pts with inadequate oral intake or who are taking diuretics may have difficulty tolerating heat exposure

• determine pt’s exposure to heat and humidity and activities prior to onset of symptoms

how to conduct a secondary assessment of heat emergencies?

• if unresponsive, perform a secondary assessment of the entire body

  • obtain vitals to help understand severity

• if conscious, perform assessment of specific areas of the body

• assess pt for muscle cramps or confusion

• examine pt’s mental status and take virals

• pay special attention to skin temp, turgor [ability of skin to resist deformation; tested by gently pinching the skin on back of hand], and level of moisture

  • helps determine severity

• check pt’s body temp with thermometer

  • pulse oximetry is also useful for heat-related emergencies

how to conduct reassessment of environmental emergencies?

• watch pt’s condition carefully for deterioration

• remove pt as quickly as possible from hot environment

• pts with heat cramps or exhaustion usually respond well to passive cooling and oral fluids

• pts with heatstroke should be immediately transported to cool ambulance, passively cooled with clothing removal, and actively cooled by spraying pt with water and fanning to enhance evaporation

• any decline in LOC is an ominous sign

• monitor vitals every 5 mins

• evaluate effectiveness of interventions

• do not overcool pt

• inform ED staff asap and document environmental conditions/activities pt was performing prior to emergency

what are symptoms of heat exhaustion vs heatstroke?

• heat exhaustion:

  • dizziness or fainting

  • heavy sweating

  • cold, pale, and clammy skin

  • nausea or vomiting

  • fast, weak pulse

  • weakness or muscle cramps

  • excessive thirst

• heatstroke:

  • headache

  • confusion or delirium

  • possible loss of consciousness

  • absence of sweating or dry skin [except in exertional heatstroke]

  • hot, red skin

  • nausea or vomiting

  • rapid heart rate

  • body temp above 104°F

how do you manage/treat a pt with heat cramps?

• promptly remove pt from hot environment, including direct sunlight

• loosen any tight clothing

• administer high flow oxygen if pt shows sign of hypoxia or respiratory distress

• rest cramping muscles → pt should sit or lie down until they subside

• replace fluids by mouth

  • give water or diluted balanced electrolyte solution, like a sports drink

  • in most cases, plain water is most useful

  • do not give salt tablets or solutions with high salt conc

• cool pt with a cool water spray or mist and add convection by fanning pt

steps to treating heat exhaustion

1. move pt to a cooler environment. remove extra clothing

2. give oxygen if indicated, check blood glucose level if indicated. perform cold-water immersion or other cooling measures as available. place pt in supine position and fan

3. if pt is fully alert, give water by mouth

4. if nausea develops, secure and transport the pt on his or her left side

how to manage heatstroke?

• move pt out of hot environment and into ambulance

• set air conditioning to maximum cooling

• remove pt’s clothing

• administer high-flow oxygen if indicated

  • if needed, assist pt’s ventilations with bag mask and appropriate airway adjuncts. if pt is unresponsive and unable to protect their airway, consider rapid transport and cooling en route

• provide cold-water immersion in an ice bath, if possible. cooling should begin immediately and continue en route to hospital

  • if not possible to cool en route and cold-water immersion is available on scene, continue on scene until cool temp is between 101°F - 102°F

• cover pt with wet towels or sheets and spray with cool water and fan them

• aggressively and repeatedly fan pt with ot without dampening the skin

• exclude other causes of altered mental status and check blood glucose

• provide rapid transport to hospital and notify hospital asap

• do not overcool pt and call ALS assistance if pt begins to shiver

what is drowning? what are the major risk factors? what is laryngospasm and why does it occur? what happens in severe cases of laryngospasm?

• drowning: process of experiencing respiratory impairment from submersion or immersion in liquid

• major risk factors:

  • alcohol consumption

  • preexisting seizure disorders

  • geriatric pts with cardiovascular disease

  • unsupervised access to water

• young children can drown in 1 inch of water if left unattended

• inhaling small amounts of either fresh or saltwater and severely irritate the larynx, causing laryngospasm → prevents more water from entering lungs

• in severe cases such as water submersion, the lungs cannot be ventilated due to significant laryngospasm

  • progressive hypoxia occurs until pt loses consciousness → spam relaxes and rescue breathing is possible

  • if pt has not already been removed from water, pt may inhale deeply, and more water may enter the lungs

what saying should you remember for water rescue? what does it mean? how is ice rescue similar to water rescue? what should you always have available during water rescue?

• in water rescue, remember: REACH, THROW, and ROW, and only then GO

  • try to reach for the pt

  • if that doesn’t work, throw the pt a rope, life preserver, or any floatable

  • use boat if one is available

  • do not attempt a swimming rescue unless you are trained and experienced in proper techniques

  • always wear a helmet and personal floatation device

• ice rescue is similar, and may involve reaching with a pole pr ladder ot throwing a rope/floatation device

  • pt who has fallen through ice may be coached into place arms onto ice, kicking and rolling out of the water, and crawling to safety

• make sure you always have immediate access to a personal flotation device and other rescue equipment

  • survival rates drastically decline the longer a victim is immersed

when should you assume a spinal injury has occurred in the water? what type of spinal injury is common in diving incidents? what should you do if a pt has a spinal injury in a diving incident?

• assume spinal injury exists with the following conditions:

  • submersion has resulted from a diving mishap or fall from a significant height

  • pt is unconscious, and no info is available to rule out the possibility of a neck injury

  • pt is conscious but reports weakness, paralysis, or numbness in arms or legs

  • you suspect spinal injury despite what witnesses say

• regardless, you should remember:

  • most spinal injuries in diving incidents affect cervical spine

  • when spinal injury is suspected, protect the neck from further injury

  • to do this, you have to stabilize the suspected injury while pt is still in water

steps to stabilizing spinal injuries in the water

1. turn the pt to a supine position by rotating the entire upper half of the body as a single unit

2. as soon as the pt is turned, begin artificial ventilation using the mouth-to-mouth method or a pocket mask

3. float a buoyant backboard under the pt

4. secure the pt to the backboard

5. remove the pt from the water

6. maintain the body’s normal temp and apply oxygen if the pt is breathing. begin CPR if breathing and pulse are absent.

what happens when a person is submerged in water colder than body temp? what is the diving reflex? why can a person survive longer in cold water than in warm water? how long should resuscitative efforts last?

• when a person is submerged in water colder than body temp, heat will be conducted from body to water

  • resulting hypothermia can protect vital organs from lack of oxygen

  • exposure to cold water will occasionally activate certain primitive reflexes, which may preserve basic body functions for prolonged periods

• when a person dives or jumps into very cold water, the diving reflex may cause immediate bradycardia → loss of consciousness and drowning

  • pt may be able to survive for an extended period of time underwater due to a lowering of the metabolic rate associated with hypothermia

  • local protocols often dictate that resuscitative efforts continue for up to 1 hr after submersion, while simultaneously rewarming the pt

what are descent problems caused by during diving? what body cavities are affected and how does the diver alleviate these symptoms? when is it a cause for concern? what happens if a pt has a ruptured eardrum while diving? what rare but serious problem may occur at the bottom of the dive, and what causes it? what is required?

• diving injuries are separated into 3 phases of the dive:

  • descent, bottom, and ascent

• descent problems usually caused by sudden increase in pressure as dive deepens

  • some body cavities cannot adjust to increased external pressure

    • pain in lungs, sinus cavities, middle ear, teeth, and area of face surrounded by diving mask

  • pain causes diver to return to the surface to equalize pressure, and problem clears up by itself

  • if diver continues to report pain, particularly in the ear, after returning to the surface should be transported to the hospital

• if a person has a ruptured eardrum while diving and cold water enters the middle ear through the eardrum, the diver may lose balance and orientation

  • diver may then shoot to surface an experience ascent problems

• problems at the bottom of the dive caused by inadequate mixing of oxygen and CO2 in the air the diver breathes and accidental feeding of poisonous CO into the breathing apparatus

  • both are the result of faulty connections in diving gear and rarely seen

  • can cause drowning or rapid ascent requiring emergency resuscitation and transport

what is an air embolism? what causes air embolism? what 3 medical conditions can arise from air embolism? what secondary problems does each one cause?

• air embolism: a dangerous ascent emergency that involves bubbles of air in the blood vessels

  • can occur on a dive as shallow as 6 feet

• caused by the diver holding their breath during rapid ascent

  • air pressure in lungs remains at high level while external pressure decreases → air inside lungs rapidly expands, causing alveoli to rupture and air to enter bloodstream

• air released from the pressure can cause:

  • pneumothorax: air enters the pleural space and compresses the lungs

  • pneumomediastinum: air enters the mediastinum, the space within the thorax that contains the heart and great vessels

  • air emboli

• pneumothorax and pneumomediastinum result in pain and severe dyspnea

• air embolus acts as a plug and prevents normal flow of blood and oxygen to a specific body part → affects the brain and spinal cord the most out of the 3

what are the signs and symptoms of air embolism?

• blotching [mottling of the skin]

• pink or bloody froth at nose and mouth

• severe pain in muscles, joints, or abdomen

• dyspnea and/or chest pain

• dizziness, nausea, and vomiting

• dysphasia [difficulty speaking]

• cough

• cyanosis

• difficulty with vision

• paralysis and/or coma

• irregular pulse and cardiac arrest

what is decompression sickness? what 3 things cause it? what is the biological mechanism behind it [how does nitrogen cause it]? what is the most striking symptom?

• decompression sickness: commonly called the bends, occurs when bubbles of gas [especially nitrogen] obstruct the blood vessels resulting from:

  • too rapid an ascent from a dive

  • too long of a dive at too deep a depth

  • repeated dives within a short period of time

• during the dive, nitrogen dissolves in the blood and tissues due to pressure

  • when the diver ascends, external pressure decreases, and dissolved nitrogen forms small bubbles in the tissues

  • bubbles can lead to problems similar to those in air embolism, but severe pain in certain tissues or spaces in the body is most common

• most striking symptom is abdominal and/or joint paint so severe that the patient literally doubles up or “bends”

what is the difference between air embolism and decrompression sickness? how does a hyperbaric chamber assist in treatment?

• air embolism occurs immediately on return to surface

• decompression sickness may not occur for several hours

• both require same emergency treatment → BLS followed by recompression in a hyperbaric chamber

  • recompression allows the bubbles of gas to dissolve into the blood and equalizes the pressure inside and outside the lungs

• gradual decompression can take place under controlled conditions to prevent bubbles from reforming

how to conduct a scene size up for drowning and diving emergencies?

• check for hazards to your crew

• never dive through moving water → even a small amount can cause a vehicle to be swept away

• never attempt a water rescue without training and equipment → call for additional resources early

• if pt is still in the water, look for best, safest means of removal

• consider trauma and spinal immobilization when the scene is a recreational setting

• check for additional pts based on where and how the emergency occured

• look for MOI indicators, and how it produced the injuries expected

how to conduct a primary assessment of a drowning and diving emergency?

• pay particular attention to chest pain, dyspnea, and complaints related to sensory changes when diving emergency is suspected

• determine LOC using AVPU → be suspicious of drug/alcohol use too

• open airway and assess breathing in unresponsive pts

• consider possibility of spinal trauma

• suction according to protocol if pt has vomited

• provide ventilation with bag mask if needed, with airway adjunct if indicated

• if pt is responsive, provide high-flow oxygen with nonrebreathing mask

• if no risk of spinal injury, position pt to protect airway from aspiration

• auscultation and reassessment of breathing sounds is key

  • provide info about diminished or gurgling sounds, and any changes in lung sounds, to ALS providers and receiving facility

  • breath sounds are significant for pts with scuba diving injuries → pneumothorax or tension pneumothorax may develop during ascent

• check for pulse

  • if unmeasurable, begin CPR and apply AED according to guidelines

  • evaluate pt for adequate perfusion and treat for shock as normal

• if MOI suggests trauma, assess for bleeding and treat appropriately

how to history take for drowning and diving emergencies?

• investigate CC

• obtain medical history and be alert for injury-specific signs and symptoms and pertinent negatives

• obtain SAMPLE history with special attention to dive parameters:

  • depth

  • length of time pt was underwater

  • time of onset of symptoms

  • previous diving activity

• note any physical activity, alcohol or drug consumption, and other medical conditions

how to conduct a secondary assessment of a drowning and diving emergency?

• if pt is responsive, focus physical exam on basis of CC and history

  • get a thorough examination of pt’s lungs, including breath sounds

• serious drownings usually result in unresponsive pts

  • begin with full body scans for hidden life threats and potential trauma

• scuba divers with problems should be assessed for indications of decompression sickness or air embolism

• focus on pain in the joints and abdomen

• assess whether your patient is getting adequate ventilation and oxygenation

• check for signs of hypothermia

• complete a detailed assessment en route to hospital if possible

• examine pt for respiratory, circulatory, and neurologic compromise

• assess peripheral pulses, skin color/discoloration, itching, pain, and paresthesia

• check pulse rate, quality, and rhythm

  • pulse and BP may he hard to palpate if pt has hypothermia

  • check for both peripheral and central pulses and listen over chest for a heartbeat if pulses are weak

• check respiratory rate, quality, and rhythm and listen for breath sounds

• assess and document pupil size and reactivity

how to conduct a reassessment of a drowning and diving emergency?

• reassess vitals and CC

• recheck pt interventions

  • pt condition may deteriorate rapidly due to pulmonary injury, fluid shifts, cerebral hypoxia, and hypothermia

  • pts with pneumothorax, air embolism, or decompression sickness may decompensate quickly

• assess pt’s mental status constantly and assess vitals every 5 mins, paying close attention to respirations and breath sounds

• document circumstances of drowning and extrication

• document and tell receiving facility:

  • how long pt was submerged

  • temp of water

  • clarity of water

  • if there was possibility of cervical spine injury

  • complete dive profile [may be available in dive log on a dive computer or from pt’s diving partner]

  • diver’s equipment and disposition of the equipment

how do you provide emergency care for drowning or diving emergencies?

• begin artificial ventilations asap, even before victim is removed from water

  • spinal immobilization must continue

• if pt is not breathing, clear any vomit manually or with suction and asisst ventilations with a bag-mask device or pocket mask

  • DO NOT roll pts onto their side or perform abdominal thrusts unless airway is obstructed → will not remove water

  • frothy sputum in airway does not require suction removal

  • when resuscitating a pt who has drowned, address airway and breathing first, THEN begin compressions and use the AED

• if pt is breathing spontaneously but has been submerged, administer oxygen

• use pulse oximetry to titrate oxygen delivery

• treat all drowning pts for hypothermia by removing wet clothing and wrapping them in blankets

• aeromedical evacuation for someone who has sustained an injury from ascent is contraindicated → decrease in air pressure may worsen decompression injury

how to provide emergency care for pts with suspected air embolism or decompression sickness

• if pt is conscious and has been suspected of having air embolism or decompression sickness:

  • remove pt from water and try to keep them calm

  • administer oxygen

  • consider possibility of pneumothorax and monitor pt’s breath sounds for development of tension pneumothorax

  • provide prompt transport to ED or nearest recompression facility for treatment

what is breath-holding syncope? what biological processes cause it? what is emergency treatment for it? what precautions can prevent most immersions?

• breath-holding syncope: a loss of consciousness caused by a decreased stimulus for breathing

  • happens to swimmers who breathe in and out rapidly and deeply before entering the water in an effort to expand their capacity to stay underwater

  • hyperventilation involved lowers CO2 levels → because high CO2 levels is the strongest stimulus for breathing, the swimmer may not feel the need ot breath even after using all oxygen in their lungs

• emergency treatment is the same as that for a drowning pt

• precautions to prevent most immersions:

  • all swimming pools should be surrounded by a fence at least 6 ft high with slats no farther apart than 3 inches, and self-closing, self locking gates

  • the most common problem is a lack of adult supervision

  • half of all teenage and adult drownings are associated with alcohol use

what are dysbarism injuries? what are altitude illnesses? what are 3 altitude illnesses that affect the CNS and pulmonary systems?

• dysbarism injuries: any signs and symptoms caused by the difference between the surrounding atmospheric pressure and the total gas pressure in various tissues, fluids, and cavities of the body

  • altitude illnesses occur when an unacclimatized person is exposed to diminished oxygen pressure in the air at high altitudes

• 3 altitude illnesses that affect the CNS and pulmonary systems:

  • acute mountain sickness

  • high altitude pulmonary edema [HAPE]

  • high altitude cerebral edema [HACE]

what is acute mountain sickness? what are signs and symptoms? how is it treated? what other causes of the same symptoms should be considered?

• acute mountain sickness: caused by diminished oxygen pressure in the air at altitudes above 5,000 feet, resulting in diminished oxygen in the blood [hypoxia]

• signs and symptoms:

  • headache

  • light-headedness

  • fatigue

  • loss of appetite

  • nausea

  • difficulty sleeping

  • shortness of breath during physical exertion

  • swollen face

• treatment: stopping ascent and descending to lower altitude

• consider other possible causes for the same symptoms, such as hypoglycemia or carbon monoxide poisoning from a camping stove

what is high-altitude pulmonary edema [HAPE]? at what altitude does it occur? what are signs and symptoms? how is it treated in the field?

• high-altitude pulmonary edema [HAPE]: fluid collects in the lungs, hindering the passage of oxygen into the bloodstream

  • can occur at altitudes of 8000 ft or greater

• signs and symptoms:

  • shortness of breath

  • cough with pink sputum

  • cyanosis

  • rapid pulse

• treatment: providing oxygen, descending to lower altitude, prompt transport

  • if respirations are inadequate, provide positive-pressure ventilation with a bag-mask device

what is high altitude cerebral edema [HACE]? what are signs and symptoms? how is it treated in the field?

• high altitude cerebral edema [HACE]: usually occurs in climbers and may accompany HAPE

  • can quickly become life threatening

• signs and symptoms:

  • severe, constant, throbbing headache

  • ataxia [lack of muscle coordination and balance]

  • extreme fatigue

  • vomiting

  • loss of consciousness

• treatment: providing oxygen, descending to lower altitude, prompt transport

  • if local protocol allows, CPAP may be helpful for a pt with respiratory distress from HAPE

how much energy is associated with lightning in amps, volts, and temps? what increases the risk of being struck by lightning? what is the splash effect? how does tissue damage from lightning differ from other electric-related injuries?

• the energy associated with lightning comprises a direct current of up to 200,000 amps and a potential of 100 million volts or more

  • temps generated from lightning vary between 20,000°F and 60,000°F

• any type of activity that exposes a person to a large, open area increases the risk of being struck by lightning

  • current associated with lightning discharge travels along the ground

• splash effect: some people are injured or killed by direct strikes; many are indirectly struck standing near an object that has been struck

• tissue damage caused by lightning is different from other electric-related injuries, because tissue damage pathway occurs OVER the skin rather than through it

• because the duration of a lightning strike is short, skin burns are usually superficial and full-thickness burns are rare

what are the 3 categories of lightning injuries and what are their symptoms?

• mild: loss of consciousness, amnesia, confusion, tingling, and other nonspecific signs and symptoms

  • if burns are present, they’re usually superficial

• moderate: seizures, respiratory arrest, dysrhythmias that spontaneously resolve, and superficial burns

• severe: cardiopulmonary arrest

  • because of delay in resuscitation, often due to occurrence in remote location, many of these pts do not survive

what should you do if the area around you has become charged? when does respiratory or cardiac arrest begin in a lightning strike victim? what is reverse triage?

• if you suddenly feel a tingling sensation or your hair stands on end, the area around has become charged → sure signs of an imminent lightning strike

  • squat down into a ball, close but not touching the ground

  • if standing near a tree or other tall object, move away as fast as possible, preferably to a low-lying area

• when someone is struck by lightning, respiratory or cardiac arrest occurs immediately, if at all

  • delayed cardiac or respiratory arrest is less likely to develop in those who are conscious following a lightning strike → most likely will survive

• focus your efforts on those who are in respiratory or cardiac arrest

  • reverse triage: used in treating multiple victims of lightning strikes, where focus is on those who are in respiratory and cardiac arrest [and would be considered deceased in conventional triage]

how to provide emergency medical care for lightning injuries?

• move pt to a place of safety, preferably a sheltered area

• manually stabilize pt’s head in a neutral in-line position and open airway with jaw-thrust maneuver

• if pt is in respiratory arrest with a pulse, begin immediate bag-mask ventilations with 100% oxygen

• if pt is in cardiac arrest, attach an AED asap and provide defibrillation

• if severe bleeding is present, control it immediately

• if CPR or ventilations are not required, address other injuries and provide continuous monitoring while en route

• pt with signs and symptoms of a lightning strike but no obvious life threats should still be transported to the ED for evaluation