Chapter 32 Environmental Emergencies

Recovery techniques

On occasion, you may be called to the scene of a drowning and find that the patient is not floating or visible in the water. An organized rescue effort in these circumstances calls for providers who are experienced with recovery techniques and equipment, including snorkel, mask, and scuba gear.

Increase or decrease heat production

One way for the body to increase its heat production is to increase the rate of metabolism of its cells through shivering. Also, people often have a natural urge to move around when they are cold. When a person is hot, he or she tends to reduce the level of activity, thus reducing heat production.

Physical condition

Patients who are ill or in poor physical condition will not be able to tolerate extreme temperatures as well as those whose cardiovascular, metabolic, and nervous systems are all functioning well. Exertion also plays a role. For instance, a brisk walk will generate body heat when you are out in the cold, but will also produce heat when it is hot.

Primary Assessment

Pay particular attention to chest pain, dyspnea, and complaints related to sensory changes when a diving emergency is suspected. Determine the patient's LOC using the AVPU scale. Be suspicious of drug and alcohol use and the effects on the patient's LOC. Open the airway and assess breathing in unresponsive patients. Consider the possibility of spinal trauma and take appropriate actions. Suction according to protocol if the patient has vomited. Provide ventilations with a BVM for inadequate breathing. Use an airway adjunct to facilitate BVM ventilations as necessary. If the patient is responsive, provide high-flow oxygen with a nonrebreathing mask, and if there is no risk of spinal injury, position the patient to protect the airway from aspiration in the event of vomiting. Auscultation and frequent reassessment of breath sounds in drowning patients is a key part of your assessment. Provide information about diminished sounds or gurgling sounds, and any changes in the patient's lung sounds, to the ALS providers and/or the receiving facility. Breath sounds are significant for patients with scuba diving injuries; while the patient ascended to the surface, a pneumothorax or tension pneumothorax may have developed. Check for a pulse. It may be difficult to find a pulse because of constriction of the peripheral blood vessels and low cardiac output, resulting in cyanosis. If the pulse is unmeasurable, begin CPR and apply your AED according to BLS and the International Liaison Committee on Resuscitation (ILCOR) guidelines. Evaluate the patient for adequate perfusion and treat for shock by maintaining normal body temperature and improving circulation through positioning. If the MOI suggests trauma, assess for bleeding and treat appropriately. Usually, the patient will be stabilized in the nearest ED. Perform all interventions en route.

Nutrition and hydration

Your body needs calories for your metabolism to function. Staying well hydrated provides water as a catalyst for much of this metabolism. A lack of food or water will aggravate both hot and cold stress. Calories provide fuel to burn, creating heat during the cold, and water provides sweat for evaporation and removing heat. Alcohol use may increase fluid loss and place the patient at greater risk for temperature-related emergencies.

Dysbarism injuries

are 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.

Hot, moist skin

body is unable to regulate core temp

Hot,dry skin

body is unable to regulate core temp

Heat cramps H

eat cramps are painful muscle spasms that occur after vigorous exercise. They do not occur only when it is hot outdoors. The exact cause of heat cramps is not well understood. Sweat produced during strenuous exercise, particularly in a warm environment, causes a change in the body's electrolyte balance. Dehydration may also play a role. Large amounts of water loss can result from excessive sweating. This loss of water may affect muscles that are being stressed and cause them to spasm. Heat cramps usually occur in the leg or abdominal muscles. When the abdominal muscles are involved, the pain and muscle spasm may be so severe that the patient appears to have an acute abdominal condition. If a patient with a sudden onset of abdominal cramps has been exercising vigorously in a hot environment, suspect heat cramps.

Most, pale cool skin

excessive fluids and slat loss

homeostasis

A balance of all systems of the body

80 TO 88F

,Signs and Symptoms -coma Cardiorespiratory resonse -weak pulse, dysrhythmias, very slow respirations Level of Conscousness -unresponsive

Lightning injuries are categorized as being

: Mild: Loss of consciousness, amnesia, confusion, tingling, and other nonspecific signs and symptoms. Burns, if present, are typically superficial. Moderate: Seizures, respiratory arrest, dysrhythmias that spontaneously resolve, and superficial burns Severe: Cardiopulmonary arrest. Because of the delay in resuscitation, often the result of occurrence in a remote location, many of these patients do not survive.

Other Water Hazards and Prevention

A person swimming in shallow water may experience breath-holding syncope, a loss of consciousness caused by a decreased stimulus for breathing. This 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. The hyperventilation involved lowers the carbon dioxide level. Because an elevated level of carbon dioxide is the strongest stimulus for breathing, the swimmer may not feel the need to breathe even after using up all the oxygen in his or her lungs. The emergency treatment for a patient with breath-holding syncope is the same as that for a drowning patient. Precautions to prevent most immersion incidents include the following: All swimming pools should be surrounded by a fence that is at least 6 feet (2 m) high, with slats no farther apart than 3 inches (8 cm), and self-closing, self-locking gates. The most common problem is a lack of adult supervision. An incident can occur when a child is unattended for only a few seconds. Half of all teenage and adult drownings are associated with alcohol use.

antivenin

A serum that counteracts the effect of venom from an animal or insect

scuba gear

A system that delivers air to the mouth and lungs at various atmospheric pressures, increasing with the depth of the dive; stands for self-contained underwater breathing apparatus.

reverse triage

A triage process used in treating multiple victims of a lightning strike, in which efforts are focused on those who are in respiratory and cardiac arrest; differs from conventional triage where such patients would be classified as deceased.

These illnesses affect the central nervous system (CNS) and pulmonary systems, and range from:

Acute mountain sickness Caused by diminished oxygen pressure in the air at altitudes above 5,000 feet (1.5 km), resulting in diminished oxygen in the blood (hypoxia) Signs and symptoms include a headache, light-headedness, fatigue, loss of appetite, nausea, difficulty sleeping, shortness of breath during physical exertion, and a swollen face. Treatment primarily consists of stopping the ascent and descending to a lower altitude. Consider other possible causes for the same symptoms, such as hypoglycemia or carbon monoxide poisoning from a camping stove. High-altitude pulmonary edema (HAPE) Fluid collects in the lungs, hindering the passage of oxygen into the bloodstream. It can occur at altitudes of 8,000 feet (2 km) or greater. Signs and symptoms include shortness of breath, cough with pink sputum, cyanosis, and a rapid pulse. High-altitude cerebral edema (HACE) Usually occurs in climbers and may accompany HAPE It can quickly become life threatening. Signs and symptoms include a severe, constant, throbbing headache; ataxia (lack of muscle coordination and balance); extreme fatigue; vomiting; and loss of consciousness. The symptoms of HACE and HAPE may overlap.

Two particularly dangerous ascent medical emergencies are:

Air embolism Decompression sickness

At a core temperature of less than 80°F (26.7°C):

All cardiorespiratory activity may cease. Pupillary reaction is slow. The patient may appear dead. Never assume that a cold, pulseless patient is dead. Patients may survive severe hypothermia if proper emergency care is provided. Perform an extended pulse check (up to a full minute). Assess at the carotid or femoral pulse. A patient in apparent cardiac arrest from hypothermia should not be considered dead until aggressive rewarming has been attempted, along with resuscitation. Remember the saying: "No one is dead unless they are warm and dead." It is important to note that patients who have died from a cause other than hypothermia will be cold to the touch; however, there will be additional, obvious signs of death such as rigor mortis. The "warm and dead" rule does not apply to such patients.

Snake Bites

At least one of these venomous species is found in every state except Alaska, Hawaii, and Maine. Use extreme caution on these calls and be sure to wear the proper protective equipment for the area. In general, only one-third of snake bites result in significant local or systemic injuries. Often, envenomation does not occur because the snake has recently struck another animal and exhausted its supply of venom for the time being. If you are unsure whether the snake was venomous, proceed as if it was, especially if the patient exhibits other signs and symptoms. A person who has been bitten by any venomous snake needs prompt transport. Notify the hospital as soon as possible if a patient has been bitten by a pit viper or coral snake. Some venoms can cause paralysis of the nervous system, and hospitals may not have appropriate antivenin on hand.

Potential signs and symptoms of an air embolism include:

Blotching (mottling of the skin) Froth (often pink or bloody) at the 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

Tick Bites continued

Both diseases are spread through the tick's saliva, which is injected into the skin when the tick attaches itself. The longer a tick stays embedded, the greater the chance that a disease will be transmitted. Bites occur most commonly during the summer months. Do not attempt to suffocate the tick with gasoline or petroleum jelly, or burn it with a lighted match; you will only increase the risk of infection or burn the patient. To remove a tick: Using fine tweezers, grasp the tick by the head and pull gently but firmly straight up so that the skin is tented. Hold this position until the tick releases. Cleanse the area with antiseptic and save the tick in a glass jar or other container so that it can be identified. Do not handle the tick with your fingers. The patient should follow up with their health care provider as soon as possible.

A heat emergency can take three forms:

Heat cramps Heat exhaustion Heat stroke

Heat exposure can cause:

Heat cramps Heat exhaustion Heat stroke

In treating a snake bite from a pit viper, follow these steps:

Calm the patient; assure him or her that venomous snake bites are rarely fatal. Place the patient in a supine position and explain that staying still will slow the spread of any venom through the system. Determine the approximate time of the bite and document your time en route to a receiving facility. This time from onset to evaluation at the facility is one of the criteria used in grading the severity of the incident and in determining the amount of antivenin to be used. Locate the bite area; clean it gently with soap and water or a mild antiseptic. Do not apply ice to the area. If the bite occurred on an arm or leg, consider the use of a pressure immobilization bandage of the extremity (eg, 40 to 70 mm Hg in the arms and 55 to 70 mm Hg in the legs) and place the affected extremity below the level of the heart. Be alert for an anaphylactic reaction to the venom and treat with an epinephrine auto-injector, as appropriate. Do not give anything by mouth, and be alert for vomiting. If, as rarely happens, the patient was bitten on the trunk, keep him or her supine and quiet and transport as quickly as possible. Monitor the patient's vital signs and mark the skin with a pen over the area that is swollen, proximal to the swelling, to note whether swelling is spreading. If there are any signs of shock, place the patient supine and administer oxygen. If the snake has been killed, be sure to bring it with you in a secure, hard-sided container so that physicians can identify it and administer the proper antivenin. Alternatively, take a picture of the snake with a cell phone and send it to the hospital ahead of time. Notify the hospital that you are bringing in a patient who has a snake bite; if possible, describe the snake. Transport the patient promptly to the hospital. If the patient shows no sign of envenomation, provide BLS as needed, place a sterile dressing over the suspected bite area, and immobilize the injury site.

People at greatest risk for a heat emergency are:

Children Geriatric patients Patients with heart disease, COPD, diabetes, dehydration, and obesity Those with limited mobility

Age

Children and older adults are more likely to experience temperature-related illness. Infants have poor thermoregulation at birth and do not have the ability to shiver and generate heat when needed until about 12 to 18 months. An infant's surface-area-to-mass ratio is larger than an adult's, so infants heat up and cool down faster. Older adults have a loss of subcutaneous tissues as they age, reducing the amount of insulation they have. Poor circulation also contributes to increased heat loss. Medications can also affect an older person's body thermostat, putting him or her at increased risk for temperature-related emergencies. Older patients are also at high risk for falls, and lying immobile on a hot or cold surface can rapidly lead to overexposure.

The venom may produce a severe systemic reaction that leads to:

Circulatory collapse Severe muscle contractions Excessive salivation Hypertension Convulsions Cardiac failure

Assessment of Heat Emergencies

Click each tab for more information on assessment of heat emergencies. Scene Size-up Primary Assessment History Taking Secondary Assessment Reassessment

Heat loss can occur in five ways:

Conduction Convection Evaporation Radiation Respiration

Conduction

Conduction is the transfer of heat from a part of the body to a colder object or substance by direct contact, such as when a warm hand touches cold metal or ice, or is immersed in water with a temperature of less than 98°F (36.7°C). Heat can also be gained if the object or substance being touched is warm.

Convection

Convection occurs when heat is transferred to circulating air, such as when cool air moves across the body surface. A person can gain heat if the air moving across the person's body is hotter than the temperature of the environment, such as in deserts or industrial settings like foundries, but it is more common to see rapid heat gain in spas and hot tubs where the water temperature may be well above body temperature.

Copperheads

Copperheads are smaller than rattlesnakes, usually 2 to 3 feet long (60 to 90 cm) with a red-copper color crossed with brown or red bands. These snakes typically inhabit woodpiles and abandoned dwellings, often close to areas of habitation. Although they account for most of the venomous snake bites in the eastern United States, copperhead bites are almost never fatal; however, note that the venom can cause significant damage to tissues in the extremities.

Coral Snakes

Coral snake venom is a powerful toxin that causes paralysis of the nervous system. Within a few hours of being bitten, a patient will exhibit bizarre behavior, followed by progressive paralysis of eye movements and respiration. Often, there are limited or no local symptoms. Successful treatment, either emergency or long-term, depends on positive identification of the snake and support of respiration. Antivenin is also available for coral snake bites, but most hospitals do not stock it. Therefore, you should notify the receiving hospital of the need for it as soon as possible. The steps for emergency care of a coral snake bite are the same as a pit viper bite.

Cottonmouths

Cottonmouths grow to about 4 feet (1 m) in length. Also called water moccasins, these snakes are olive or brown, with black cross-bands and a yellow undersurface. They are water snakes and have a particularly aggressive pattern of behavior. Although fatalities from these snake bites are rare, tissue destruction from the venom may be severe.

Decompression sickness

Decompression sickness, commonly called the bends, occurs when bubbles of gas, especially nitrogen, obstruct the blood vessels. This condition results 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 that is being breathed dissolves in the blood and tissues because it is under pressure. When the diver ascends, the external pressure decreases, and the dissolved nitrogen forms small bubbles within the tissues. These bubbles can lead to problems similar to those that occur in air embolism (blockage of tiny blood vessels, depriving parts of the body of their normal blood supply), but severe pain in certain tissues or spaces in the body is the most common problem. The most striking symptom is abdominal and/or joint pain so severe that the patient literally doubles up or "bends." You may find it difficult to distinguish between air embolism and decompression sickness. As a general rule, air embolism occurs immediately on return to the surface, whereas the symptoms of decompression sickness may not occur for several hours. The emergency treatment is the same for both: basic life support (BLS) followed by recompression in a hyperbaric chamber. Recompression treatment allows the bubbles of gas to dissolve into the blood and equalizes the pressures inside and outside the lungs. Once these pressures are equalized, gradual decompression can be accomplished under controlled conditions to prevent the bubbles from re-forming.

Diving injuries are separated into three phases of the dive: ascent, decent, and bottom.

Descent Emergencies Emergencies at the Bottom

Descent Emergencies

Descent problems are usually caused by the sudden increase in pressure on the body as the person dives deeper into the water. Some body cavities cannot adjust to the increased external pressure of the water, resulting in severe pain to the lungs, the sinus cavities, the middle ear, the teeth, and the area of the face surrounded by the diving mask. Usually, the pain caused by these "squeeze problems" forces the diver to return to the surface to equalize the pressures, and the problem clears up by itself. A diver who continues to report pain, particularly in the ear, after returning to the surface should be transported to the hospital. A special problem may develop in a person with a perforated tympanic membrane (ruptured eardrum) while diving. If cold water enters the middle ear through a ruptured eardrum, the diver may sustain a loss of balance and orientation. The diver may then shoot to the surface and experience ascent problems.

Common Marine Envenomations

Dogfish Dragonfish Fire Coal Hydroids Jellyfish Lionfish Marine Snail Portuguese man-of-war Ratfish Scorpion fish Sea anemone Sea urchins Starfush Stingray Stonefish Tigerfish Toadfish Weever fish

You should also investigate:

Exposure to wet conditions Inadequate insulation from cold or wind Restricted circulation from tight clothing or shoes or circulatory disease Fatigue Poor nutrition Alcohol or drug abuse Hypothermia Diabetes Cardiovascular disease Age

The following body parts are especially vulnerable to cold injury:

Extremities (feet and hands) Ears Nose Face

Environmental conditions

Factors such as air temperature, humidity level, and wind can complicate or improve environmental situations. Extremes in temperature and humidity are not needed to produce hot or cold injuries. Many hypothermia cases occur at temperatures between 30°F (-1°C) and 50°F (10°C). Most heat stroke cases occur when the temperature is 80°F (26.7°C) and the humidity is 80%. When evaluating your patient's condition, consider the environment and whether your patient is prepared for that situation.

The two types of spider capable of delivering serious, life-threatening bites are:

Female black widow spider Brown recluse spider

breath-holding syncope

Loss of consciousness caused by a decreased breathing stimulus.

Water Rescue

First, try to reach for the patient. If that does not work, throw the patient a rope, a life preserver, or any floatable object that is available. Next, use a boat if one is available. Do not attempt a swimming rescue unless you are trained and experienced in the proper techniques. Even then, you should always wear a helmet and a personal flotation device. In cold climates or cold-water locations, rapid hypothermia is also a concern for rescuers. The steps for ice rescue are similar and may involve reaching with a pole or ladder or throwing a rope or floatation device. A victim who has fallen through the ice may also be coached into placing his or her arms out of the water and onto the ice, kicking and rolling out of the water, and crawling to safety. Because the success of any water rescue depends on how rapidly the patient is removed from the water and ventilated, make sure you always have immediate access to personal flotation devices and other rescue equipment. Survival rates drastically decline the longer a victim is immersed. Cold-water drowning survival rates are somewhat higher.

Secondary Assessment

Focus your physical examination on the severity of hypothermia, assessing the areas of the body directly affected by cold exposure, and the degree of damage. Determine the degree and extent of cold injury, as well as any other injuries or conditions that may not have been initially detected. The numbing effect of cold, both on the brain and on the body, may impair your patient's ability to tell you about other injuries or illnesses, so do a careful examination of the patient's entire body. Vital signs may be altered by the effects of hypothermia and can be an indicator of its severity. Respirations may be slow and shallow, resulting in low oxygen levels in the body. Low blood pressure and a slow pulse also indicate moderate to severe hypothermia. Carefully evaluate your patient for changes in mental status using the AVPU scale. Determine a core body temperature using a hypothermia thermometer, if local protocols allow. Pulse oximetry will often be inaccurate due to the lack of perfusion in the extremities.

Frostbite

Frostbite is the most serious local cold injury because the tissues are actually frozen. Freezing permanently damages cells. The presence of ice crystals within the cells may cause physical damage. The change in the water content in the cells may also cause changes in the concentration of critical electrolytes, producing permanent changes in the chemistry of the cell. When the ice thaws, further chemical changes occur in the cell, causing permanent damage or cell death, called necrosis or gangrene. If gangrene occurs, the dead tissue must be surgically removed, sometimes by amputation. Following less-severe damage, the exposed part will become inflamed, tender to touch, and unable to tolerate exposure to cold. Frostbite can be identified by the hard, waxy feel of the affected tissues. The injured part feels firm to frozen as you gently touch it. If the frostbite is only skin deep, it will feel leathery or thick instead of hard. Blisters and swelling may be present. In light-skinned people with a deep injury that has thawed or partially thawed, the skin may appear red or white, or it may be mottled and cyanotic (purple and blue). The depth of skin damage will vary. With superficial frostbite, only the skin is frozen. With deep frostbite, the deeper tissues are frozen as well. You may not be able to tell superficial from deep frostbite in the field.

Cold injuries include:

Frostnip and immersion foot Frostbite

Frostnip and immersion foot

Frostnip occurs after prolonged exposure to the cold, when the skin may freeze but the deeper tissues are unaffected. Because frostnip is usually painless, the patient often is unaware that a cold injury has occurred. Immersion foot (also called trench foot) occurs after prolonged exposure to cold water. It is particularly common in hikers or hunters who stand for a long time in a river or lake. With both frostnip and immersion foot, the skin is pale (blanched) and cold to the touch; normal color does not return after palpation of the skin. In some cases, the skin of the foot will be wrinkled, but it can also remain soft. The patient reports loss of feeling and sensation in the injured area.

Heat exhaustion

Heat exhaustion is also called heat prostration or heat collapse. The most common heat emergency Heat exposure, stress, and fatigue are causes of heat exhaustion, which is caused by hypovolemia as the result of the loss of water and electrolytes from heavy sweating. People who work or exercise vigorously and those who wear heavy clothing in a warm, humid, or poorly ventilated environment are particularly prone to heat exhaustion. The signs and symptoms of heat exhaustion and those of associated hypovolemia include: Dizziness, weakness, or syncope signifying a change in level of consciousness with accompanying nausea, vomiting, or headache Muscle cramping, including abdominal cramping Onset while working vigorously or exercising in a hot, humid, or poorly ventilated environment and sweating heavily Onset, even at rest, in the older and infant age groups in hot, humid, and poorly ventilated environments or after extended time in hot, humid environments Cold, clammy skin with ashen pallor Dry tongue and thirst Normal vital signs, although the pulse is often rapid and weak (an indication for use of pulse oximetry) and the diastolic blood pressure may be low Normal or slightly elevated body temperature; on rare occasions, as high as 104°F (40°C) People who are not acclimatized to the environment may also experience onset at rest.

All three forms may be present in the same patient because untreated heat exhaustion may progress to heat stroke.

Heat stroke is life threatening.

Heat stroke

Heat stroke is the least common but most serious heat emergency. Occurs when the body is subjected to more heat than it can handle and normal mechanisms for getting rid of the excess heat are overwhelmed Body temperature rises rapidly to the level at which tissues are destroyed. Untreated heat stroke always results in death. Heat stroke can develop: In patients during vigorous physical activity or when they are outdoors or in a closed, poorly ventilated, humid space During heat waves among people (particularly geriatric patients) who live in buildings with no air conditioning or with poor ventilation In children who are left unattended in a locked vehicle on a hot day Many patients with heat stroke have hot, dry, flushed skin because their sweating mechanism has been overwhelmed. A patient can have heat stroke even if he or she is still sweating. This presentation is often seen in endurance athletes, military personnel, or emergency providers who wear personal protective equipment. Body temperature may rise to 106°F (41.1°C) or more. As core temperature rises, the patient's LOC decreases, resulting in unconsciousness. Often, the first sign of heat stroke is a change in behavior. The patient becomes unresponsive very quickly and seizures may occur. Pulse is usually rapid and strong at first, but as the patient becomes increasingly unresponsive, the pulse becomes weaker and the blood pressure falls. Respiratory rate increases as the body attempts to compensate.

Hypothermia can be:

Mild Severe

Hymenoptera Stings

Hymenoptera (bees, wasps, yellow jackets, and ants) stings are painful but are not a medical emergency. Remove the stinger and, if still present, the venom sac. This is best done by using a firm-edged item such as a credit card to scrape the stinger and sac off the skin. Use ice packs to assist in controlling pain from a hymenoptera sting. The signs and symptoms of anaphylaxis are: Flushed skin Low blood pressure Difficulty breathing, usually associated with reactive airway sounds such as wheezes, or, in severe cases, diminished or absent breath sounds Hives (urticaria) may develop near the site of envenomation or centrally on the body. The patient can also have swelling to the throat and tongue. Anaphylaxis is a true emergency and can be fatal if not recognized and treated quickly. If anaphylaxis develops, be prepared to assist the patient in administering an epinephrine auto-injector (EpiPen), and support the airway and breathing should the patient experience significant respiratory compromise.

Hypothermia

Hypothermia means "low temperature" and occurs when core temperature falls below 95°F (35°C). To protect itself against heat loss, the body: Constricts blood vessels in the skin, which results in the characteristic appearance of blue lips and/or fingertips Creates additional heat by shivering As cold exposure worsens and these mechanisms are overwhelmed, many body functions slow down and mental status deteriorates. Eventually, the functioning of key organs, such as the heart, begins to slow. Untreated, this can lead to death. Hypothermia is more common among: Geriatric, pediatric, and ill people, who are less able to adjust to temperature extremes Patients with injuries or illness, such as burns, shock, head injury, stroke, generalized infection, injuries to the spinal cord, diabetes, and hypoglycemia Patients who have taken certain drugs or consumed alcohol

Secondary Assessment

If the patient is responsive, focus your physical examination on the basis of the chief complaint and the history obtained, including a thorough examination of the patient's lungs, including breath sounds. Serious drowning situations typically result in an unresponsive patient. Begin with a full-body scan to look for hidden life threats and potential trauma, even if trauma is not suspected. A scuba diver with problems should be assessed for indications of decompression sickness or an air embolism. Focus on pain in the joints and the abdomen. Pay attention to whether your patient is getting adequate ventilation and oxygenation. Check for signs of hypothermia. Time and personnel permitting, complete a detailed assessment en route to the hospital. Examine the patient for respiratory, circulatory, and neurologic compromise. Assess for peripheral pulses, skin color and discoloration, itching, pain, and paresthesia. Check the patient's pulse rate, quality, and rhythm. Pulse and blood pressure may be difficult to palpate in a patient with hypothermia. Check for both peripheral and central pulses, and listen over the chest for a heartbeat if pulses are weak. Check the respiratory rate, quality, and rhythm and listen for breath sounds. Assess and document pupil size and reactivity.

Secondary Assessment

If your patient is unresponsive, perform a secondary assessment of the entire body. Obtain vital signs to help understand the severity of the emergency. If the patient is conscious, perform an assessment of specific areas of the body. Assess the patient for muscle cramps or confusion. Examine the patient's mental status and take the patient's vital signs. Pay special attention to the patient's skin temperature, turgor, and level of moisture. Perform a careful neurologic examination. Patients with hyperthermia will often have tachycardia and tachypnea. Assessment of the patient's skin will help determine the severity of the emergency. Check the patient's body temperature with a thermometer, depending on protocol. In patients with a heat-related emergency, monitoring of pulse oximetry is also useful.

Mild

Mild hypothermia occurs when the core temperature is between 90°F and 95°F (32.2°C and 35°C). The patient is usually alert and shivering in an attempt to generate heat through muscular activity. Pulse rate and respirations are usually rapid. The skin in light-skinned people can be red, but may eventually appear pale, then cyanotic. People in a cold environment may have blue lips or fingertips because of the body's constriction of blood vessels at the skin to retain heat.

Severe

More severe hypothermia occurs when the core temperature is less than 90°F (32.2°C). Shivering stops and muscular activity decreases. At first, small, fine muscle activity such as coordinated finger motion ceases. Eventually, as the temperature falls further, all muscle activity stops and mental status deteriorates.

Primary Assessment

In a cold emergency, your patient's chief complaint may be only that he or she is cold, or the cold may be an additional complication of an existing medical injury or trauma. Perform a rapid examination to determine whether a life threat exists and if so, treat it. If the chief complaint is simply feeling cold, quickly assess the patient's core temperature by placing the back of your hand on the abdomen. Evaluate the patient's mental status using the AVPU scale. An altered mental status indicates the intensity of the cold injury. Consider spinal immobilization based on your scene size-up and the chief complaint. If you believe the patient is in cardiac arrest, proceed directly to ("C") by providing high-quality chest compressions, then address airway and breathing ("A" and "B") afterward. If your patient's breathing is slow or shallow, ventilation with a bag-valve mask (BVM) may be necessary. Use warmed and humidified oxygen if it is available, because it helps to warm the patient from the inside out. If you cannot feel a radial pulse, gently palpate for a carotid pulse and wait for up to 60 seconds before you decide whether the patient is pulseless. Your assessment of the patient's skin will not be helpful in determining shock. Assume that shock is present and treat it appropriately. Bleeding may be difficult to find because of the slow-moving circulation and thick clothing. All patients with hypothermia require rapid transport for evaluation and treatment. As you package your patient for transport, work quickly, safely, and gently. Rough handling of a patient with hypothermia may cause a cold, slow, weak heart to fibrillate. If transportation is delayed, protect the patient from further heat loss.

The rate and amount of heat loss or gain by the body can be modified in three ways:

Increase or decrease heat production Move to an area where heat loss is decreased or increased Wear the appropriate clothing for the environment

History Taking

Investigate the chief complaint. Obtain a medical history and be alert for injury-specific signs and symptoms as well as any pertinent negatives. If possible, find out how long your patient has been exposed to the cold environment, either from the patient or bystanders. Medications and underlying medical conditions may have an impact on the way cold affects the patient's metabolism. The patient's last oral intake and activity prior to the exposure will help to determine the severity of the cold injury.

History Taking

Investigate the chief complaint. Obtain a medical history and be alert for injury-specific signs and symptoms as well as any pertinent negatives. Obtain a SAMPLE history with special attention to the dive parameters, including: Depth Length of time the patient was underwater Time of onset of symptoms Previous diving activity Note any physical activity, alcohol or drug consumption, and other medical conditions.

History Taking

Investigate the chief complaint. Obtain a medical history and be alert for specific signs and symptoms such as the absence of perspiration, decreased LOC, confusion, muscle cramping, nausea, and vomiting. Obtain a SAMPLE history. Patients with inadequate oral intake, or who are taking diuretics, may have difficulty tolerating exposure to heat. Determine your patient's exposure to heat and humidity and activities prior to the onset of symptoms.

Managing Heat Stroke

Move the patient out of the hot environment and into the ambulance. Set the air conditioning to maximum cooling. Remove the patient's clothing. Administer high-flow oxygen if indicated, if this was not already done as part of the primary assessment. If needed, assist the patient's ventilations with a BVM and appropriate airway adjuncts as per your protocol. If the patient is unresponsive and unable to protect his or her airway, consider rapid transport and cooling en route. Consult medical control if available. Provide cold-water immersion in an ice bath, if possible. Cooling should begin immediately and continue en route to the hospital. If it is not possible to cool en route and cold-water immersion is available at the scene, continue cold-water immersion at the scene until the core body temperature is between 101°F and 102°F (38.3°C and 38.9°C). Cover the patient with wet towels or sheets, or spray the patient with cool water and fan him or her to quickly evaporate the moisture on the skin. Aggressively and repeatedly fan the patient with or without dampening the skin. Exclude other causes of altered mental status and check blood glucose level, if possible. Provide rapid transport to the hospital. Notify the hospital as soon as possible. Do not overcool the patient. Call for ALS assistance if the patient begins to shiver.

Emergency Medical Care for Lightning Injuries

Move the patient to a place of safety, preferably in a sheltered area. If you suddenly feel a tingling sensation or your hair stands on end, the area around you has become charged—a sure sign of an imminent lightning strike. Make yourself as small a target as possible by squatting down into a ball, with only your feet touching the ground. If you are standing near a tree or other tall object, move away as fast as possible, preferably to a low-lying area. Lightning tends to strike objects that project from the ground. When a person is struck by lightning, respiratory or cardiac arrest, if it occurs, usually occurs immediately. Delayed respiratory or cardiac arrest is much less likely to develop in those who are conscious following a lightning strike; most of these people will survive. Focus your efforts on those who are in respiratory or cardiac arrest. This process, called reverse triage, differs from conventional triage, where such patients would ordinarily be classified as deceased. For a patient who has been struck by lightning, manually stabilize the patient's head in a neutral in-line position and open the airway with the jaw-thrust maneuver. If the patient is in respiratory arrest with a pulse, begin immediate BVM ventilations with 100% oxygen. If the patient is in cardiac arrest, attach an AED as soon as possible and provide defibrillation if indicated. 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 to the hospital. A patient with signs and symptoms of a lightning strike, but no obvious life threats, should still be transported to the ED for evaluation.

Scene Size-up

Note environmental conditions. Air temperature, wind chill, and whether it is wet or dry are important aspects of scene size-up and will likely affect the patient. Ensure that the scene is safe for you and other emergency responders. Identify potential safety hazards, such as wet grass, mud, or icy streets. Cold environments may present special challenges for you and your patient; consider special hazards such as avalanches. Use appropriate standard precautions and consider the number of patients you may have. Summon additional help, such as a search and rescue team, as quickly as possible. Look for indicators of the mechanism of injury (MOI).

Primary Assessment

Observe how the patient interacts with you and the environment. Ask about the chief complaint. Prolonged heat exposure may stress the heart, causing a heart attack. Perform a rapid scan and avoid tunnel vision. Assess the patient's mental status using the AVPU scale. The more altered the patient's mental status is, the more serious the heat emergency. Assess the airway and breathing and treat any life threats. If the patient is unresponsive: Be cautious of how you open the airway. Consider spinal immobilization if trauma is a possibility. Insert an airway and provide BVM ventilations. If circulation is adequate, assess the patient for perfusion and bleeding. Assess the patient's skin condition carefully. Treat the patient aggressively for shock by removing the patient from the heat and positioning the patient to improve circulation. If your patient has any signs of heat stroke, provide rapid transport.

Scene Size-up

Perform an environmental assessment. The heat emergency may be secondary. If the patient is unconscious, has an altered mental status, or requires intravenous fluids to treat shock, consider calling for ALS assistance. Look for indicators of the MOI. It is harmful to allow heat to persist for any amount of time; therefore, cooling prior to transport is indicated if facilities are available. If the patient is placed in a cold-water immersion bath upon your arrival, monitor the patient in the water and assist as necessary. Do not remove the patient until the temperature has normalized to the appropriate level, between 101°F and 102°F (38.3°C and 38.9°C). Do not overcool the patient. Overcooling can lead to shivering, which generates more heat. Monitor the patient closely. Protect yourself from the heat and stay hydrated. Long-sleeved shirts and long pants may be uncomfortable in warm weather; however, they can help protect you from being splashed by blood or other body fluids.

Factors affecting exposure include:

Physical condition Age Nutrition and hydration Environmental conditions

Emergencies at the Bottom

Problems related to the bottom of the dive are rarely seen. They include inadequate mixing of oxygen and carbon dioxide in the air the diver breathes and accidental feeding of poisonous carbon monoxide into the breathing apparatus. Both are the result of faulty connections in the diving gear. These situations can cause drowning or rapid ascent; they require emergency resuscitation and transport of the patient.

Radiation

Radiation is the transfer of heat by radiant energy. Radiant energy is a type of invisible light that transfers heat. Radiation causes heat loss, such as when a person stands in a cold room. Heat can also be gained by radiation—for example, when a person stands by a fire.

The primary purpose of the venom is to kill small animals and facilitate the digestive process.

Rattlesnakes Copperheads Cottonmouths

Rattlesnakes

Rattlesnakes have many patterns of color, often with a diamond pattern. They can grow to 6 feet (2 m) or more in length.

Reassessment

Reassess vital signs and the chief complaint. Identify and treat changes in the patient's condition. Keep a close eye on your patient's LOC and vital signs. As the body rewarms, the sudden redistribution of fluids and the release of built-up chemicals can have harmful effects, including cardiac dysrhythmias. Be vigilant even if the patient's condition appears to be improving. Review all treatments that have been performed. In a cold-related emergency, depending on your local protocols, your treatment may only include oxygen delivery. Reassess oxygen delivery and continue to provide for a warm environment by removing any wet or frozen clothing. Do not remove any clothing frozen to the patient's skin. Communicate all of the information you have gathered to the receiving facility. Your documentation should always include the patient's physical status, the conditions at the scene, information gathered from bystanders, and any changes in the patient's mental status during treatment and transport.

Reassessment

Reassess vital signs and the chief complaint. Recheck patient interventions. The patient's condition may deteriorate rapidly because of pulmonary injury, fluid shifts in the body, cerebral hypoxia, and hypothermia. Patients with pneumothorax, air embolism, or decompression sickness may decompensate quickly. Assess your patient's mental status constantly, and assess vital signs at least every 5 minutes. Pay particular attention to respirations and breath sounds. Document the circumstances of the drowning and extrication. The receiving facility personnel will need to know how long the patient was submerged, the temperature of the water, the clarity of the water, and whether there was any possibility of cervical spine injury. If you respond to a diving incident, the receiving facility personnel will also need a complete dive profile to properly treat your patient. This information may be available in a dive log, on a dive computer, or from the patient's diving partners. If possible, bring all of the diver's equipment to the hospital. Be sure to document the disposition of this equipment.

Additional aspects of drowning emergencies include:

Recovery techniques Resuscitation efforts

Respiration

Respiration causes body heat loss as warm air in the lungs is exhaled into the atmosphere and cooler air is inhaled. In warm climates, the air temperature can be well above body temperature, causing an individual to gain heat with each breath.

Ticks commonly carry two infectious diseases:

Rocky Mountain spotted fever Not limited to the Rocky Mountains area Occurs within 7 to 10 days after a bite by an infected tick Symptoms include: Nausea and vomiting Headache Weakness Paralysis Possible cardiorespiratory collapse Lyme disease Originally seen only in Connecticut, it has now been reported in all states with the exception of Hawaii. Occurs most commonly in the Northeast and the Great Lake states The first symptoms are generally fever and flulike symptoms, sometimes associated with a bull's-eye rash that may spread to several parts of the body. After a few days or weeks, painful swelling of the joints, particularly the knees, occurs.

Assessment of Drowning and Diving Emergencies

Scene Size-up Primary Assessment History Taking Secondary Assessment Reassessment

Click on each tab for more information on assessment of cold injuries.

Scene Size-up Primary Assessment History Taking Secondary Assessment Reassessment

89 to 92F

Signs and Symptoms -loss of coordination, muscle stiffness Cardiorespiratory response -slowing respiration, slow pulse Level of Conscousness -confused, lethargic, sleepy

99 to 95F

Signs and Symptoms -shivering, foot stamping Cardiorespiratory response -constricted blood vessels, rapid breathing Level of Conscousness -withdrawm

<80F

Signs and Symptoms Apparent death Cardiorespiratory response -cardiac arrest Level of Conscousness -unresponsive

Characteristics of Systemic Hypothermia

Signs and Symptoms Cardiorespiratory response Level of Conscousness

Scene Size-up

Standard precautions should include gloves and eye protection at a minimum. Check for hazards to your crew. Never drive through moving water—a small amount can cause the vehicle to be swept away. Never attempt a water rescue without proper training and equipment. Call for additional resources early. If your patient is still in the water, look for the best, safest means of removal. Consider trauma and spinal immobilization when the scene is a recreational setting. Check for additional patients based on where and how the emergency occurred. Look for indicators of the MOI and consider how the MOI produced the injuries expected.

Treating Heat Exhaustion

Step 1 Move the patient to a cooler environment. Remove extra clothing. Step 2 Give oxygen if indicated. Check the patient's blood glucose level if indicated. Perform cold-water immersion or other cooling measures as available. Place the patient in a supine position and fan the patient. Step 3 If the patient is fully alert, give water by mouth. Step 4 If nausea develops, secure and transport the patient on his or her left side.

Stabilizing Spinal Injury in the Water

Step 1 Turn the patient to a supine position by rotating the entire upper half of the body as a single unit. Step 2 As soon as the patient is turned, begin artificial ventilation using the mouth-to-mouth method or a pocket mask. Step 3 Float a buoyant backboard under the patient. Step 4 Secure the patient to the backboard. Step 5 Remove the patient from the water. Step 6 Maintain the body's normal temperature and apply oxygen if the patient is breathing. Begin CPR if breathing and pulse are absent.

Management of Heat Cramps

Take the following steps to treat heat cramps in the field: Promptly remove the patient from the hot environment, including direct sunlight. Loosen any tight clothing. Administer high-flow oxygen if indicated (the patient shows signs of hypoxia or respiratory distress), if this was not already done as part of the primary assessment. Rest the cramping muscles. Have the patient sit or lie down until the cramps subside. Replace fluids by mouth. Give water or a diluted (half-strength) balanced electrolyte solution, such as a sports drink. In most cases, plain water is the most useful. Do not give salt tablets or solutions that have a high salt concentration. Cool the patient with cool water spray or mist, and add convection to the cooling method by manually or mechanically fanning the patient. The best preventive and treatment strategy is hydration by drinking sufficient quantities of water.

Scorpion Stings

The Centrurodes sculpturatus is the only venomous scorpion in the United States. It is found naturally in Arizona and New Mexico, as well as parts of Texas, California, and Nevada, but it may be kept as a pet by anyone.

turgor

The ability of the skin to resist deformation; tested by gently pinching skin on the forehead or back of the hand.

Brown recluse spider

The brown recluse spider (Loxosceles) is dull brown and 1-inch (3-cm) long. The shorthaired body has a violin-shaped mark, brown to yellow in color, on its back. Although the brown recluse spider lives mostly in the southern and central parts of the country, it may be found throughout the continental United States. The spider tends to live in dark areas—in corners of old, unused buildings; under rocks; and in woodpiles. In cooler areas, it moves indoors to closets, drawers, cellars, and clothing. The venom of the brown recluse spider is cytotoxic; that is, it causes severe local tissue damage. Typically, the bite is not painful at first but becomes so within hours. The area becomes swollen and tender, developing a pale, mottled, cyanotic center and possibly a small blister. Over the next several days, a scab of dead skin, fat, and debris forms and digs down into the skin, producing a large ulcer that may not heal unless treated promptly. Transport patients with such symptoms as soon as possible. Brown recluse spider bites rarely cause systemic symptoms and signs. When they do, provide BLS and prompt transport to the ED. It is helpful if you can identify the spider and either safely bring it to the hospital with the patient, or take a picture of the spider and send it to the hospital ahead of time.

Venomous snakes native to the United States all have hollow fangs in the roof of the mouth that inject the venom from two sacs at the back of the head.

The classic appearance of the venomous snake bite is two small puncture wounds, usually about 0.5 inch (1 cm) apart, with discoloration and swelling, and the patient usually reports pain surrounding the bite. A snake bite with other tooth marks may be from a nonvenomous snake.

Evaporation

The conversion of any liquid to a gas, which is a process that requires energy, or heat Evaporation is the natural mechanism by which sweating cools the body. People who exercise vigorously in a cool environment may sweat and feel warm at first, but later, as their sweat evaporates, they can become cold. Radiation

If possible, determine:

The duration of the exposure The temperature to which the body part was exposed The wind velocity during exposure These will help you determine the severity of a local cold injury.

Injuries From Marine Animals

The emergency treatment of common coelenterate envenomations consists of the following steps: Remove the patient from the water, and remove the remaining tentacles by scraping them off with the edge of a stiff object such as a credit card. Do not use your ungloved hand to remove the tentacles, because self-envenomation will occur. On very rare occasions, a patient may have a systemic allergic reaction to the sting of one of these animals. Treat such a patient for anaphylactic shock and provide rapid transport to the hospital. Limit further discharge of nematocysts by avoiding fresh water, wet sand, showers, or careless manipulation of the tentacles. Keep the patient calm and reduce motion of the affected extremity. Toxins from the spines of urchins; stingrays; and certain spiny fish such as the lionfish, scorpion fish, or stonefish are heat sensitive. Persistent pain may respond to immersion in hot water (110°F to 115°F [43.3°C to 46.1°C]) for 30 minutes. If available, immersion in vinegar may also help alleviate the symptoms. Provide transport to the ED.

Emergency Care of Local Cold Emergencies

The emergency treatment of local cold injuries in the field should include the following steps: Remove the patient from further exposure to the cold. Handle the injured part gently, and protect it from further injury. Remove any wet or restricting clothing from the patient, especially over the injured part. With frostnip, contact with a warm object may be all that the patient needs. Use your hands or the patient's own body (for example, have the patient tuck his or her hands into the armpits). During rewarming, the affected part will often tingle and become red in light-skinned people. With immersion foot, remove wet shoes, boots, and socks, and rewarm the foot gradually, protecting it from further cold exposure. Splint the extremity and cover it loosely with a dry, sterile dressing. Never rub or massage injured tissues, which could cause further damage. Do not reexpose the injury to cold. With a late or deep cold injury, such as frostbite, remove any jewelry from the 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 rewarm the part. Rewarming of the frostbitten extremity is best accomplished in the ED. Do not allow the patient to stand or walk on a frostbitten foot. Evaluate the patient's general condition for the signs or symptoms of systemic hypothermia. Support the vital functions as necessary, and provide rapid transport to the hospital. If prompt hospital care is unavailable and medical control instructs you to begin rewarming in the field, use a warm-water bath. Immerse the frostbitten part in water with a temperature between 102°F and 104°F (38.9°C and 40°C). Check the water temperature with a thermometer before immersing the limb, and recheck it frequently during the rewarming process. The water temperature should never exceed 105°F (40.6°C). Keep the frostbitten part in the water until it feels warm and sensation has returned to the skin. Dress the area with dry, sterile dressings, placing them also between injured fingers or toes. Expect the patient to report severe pain. Cover the frostbitten part with soft, padded, sterile cotton dressings. If blisters have formed, do not break them.

Lightning

The energy associated with lightning is comprised of direct current of up to 200,000 amps and a potential of 100 million volts or more. Temperatures generated from lightning vary between 20,000°F and 60,000°F (11,000°C and 33,000°C). Any type of activity that exposes the person to a large, open area increases the risk of being struck by lightning. The current associated with the lightning discharge travels along the ground. Although some people are injured or killed by a direct lightning strike, many people are indirectly struck when standing near an object that has been struck by lightning, such as a tree (splash effect). The tissue damage caused by lightning is different from that caused by other electricity-related injuries (ie, high-power-line injuries) because the tissue damage pathway usually occurs over the skin, rather than through it. Look for entrance and exit wounds. The exit wound does not necessarily occur on the same side of the body. Because the duration of a lightning strike is short, skin burns are usually superficial; full-thickness (third-degree) burns are rare.

Female black widow spider

The female black widow spider (Latrodectus) measures approximately 2 inches (5 cm) long with its legs extended. It is usually black and has a distinctive, bright red-orange marking in the shape of an hourglass on its abdomen. The female black widow spider is larger and more toxic than the male. Black widow spiders are found in every state except Alaska. They prefer dry, dim places around buildings, in woodpiles, and among debris. The bite of the black widow spider is sometimes overlooked. If the site becomes numb right away, the patient may not even recall being bit. Most black widow spider bites cause localized pain and symptoms, including agonizing muscle spasms. In some cases, a bite on the abdomen causes muscle spasms so severe that the patient may be thought to have an acute abdominal condition, possibly peritonitis. The main danger is that the black widow's venom can damage nerve tissues, as it is a neurotoxin. Other systemic symptoms include dizziness, sweating, nausea, vomiting, and rashes. Tightness in the chest and difficulty breathing develop within 24 hours, as well as severe cramps, with boardlike rigidity of the abdominal muscles. Generally, these signs and symptoms subside over 48 hours. If necessary, a physician can administer a specific antivenin, but because of a high incidence of side effects, its use is reserved for very severe bites, for older or very feeble patients, and for children younger than 5 years. In children, these bites can be fatal. Emergency treatment of a black widow spider bite consists of BLS for the patient in respiratory distress. More often, the patient will only require pain relief. Transport the patient to the ED as soon as possible for treatment. If possible, safely bring the spider to the hospital or take a photo of the spider with a cell phone and send it to the hospital ahead of time so that it can be definitively identified.

Risk factors include:

The inability to acclimate to the heat Vigorous exercise, during which sweat loss can exceed 1 liter an hour, causing loss of fluid and electrolytes

Air embolism

The most dangerous, and most common, emergency in scuba diving is an air embolism, a condition involving bubbles of air in the blood vessels. An air embolism may occur on a dive as shallow as 6 feet (2 m). The problem starts when the diver holds his or her breath during a rapid ascent. The air pressure in the lungs remains at a high level while the external pressure on the chest decreases. As a result, the air inside the lungs expands rapidly, causing the alveoli in the lungs to rupture. The air released from this rupture can cause: Pneumothorax (where air enters the pleural space and compresses the lungs) Pneumomediastinum (where air enters the mediastinum—the space within the thorax that contains the heart and great vessels) Air emboli Pneumothorax and pneumomediastinum both result in pain and severe dyspnea. An air embolus acts as a plug and prevents the normal flow of blood and oxygen to a specific part of the body. The brain and spinal cord are the organs most severely affected by air embolism.

Move to an area where heat loss is decreased or increased

The most obvious way to decrease heat loss from radiation and convection is to move out of a cold environment and seek shelter from the wind. The same holds true for a patient who is too hot. Simply moving the patient into the shade can reduce the ambient temperature by 10 degrees or more. If you cannot move the patient, create shade and increase air movement by fanning the patient.

As the core temperature drops toward 85°F (29.4°C):

The patient becomes lethargic and usually stops fighting the cold. Level of consciousness (LOC) decreases, and the patient may try to remove his or her own clothes. Poor coordination and memory loss follow, along with reduced or complete loss of sensation to touch, mood changes, and impaired judgment. The patient becomes less communicative, experiences joint or muscle stiffness, and has trouble speaking. The patient begins to appear stiff or rigid.

Venomous snakes in the United States include:

The rattlesnake (Crotalus) The copperhead (Agkistrodon contortrix) The cottonmouth, or water moccasin (Agkistrodon piscivorus) The coral snakes (Micrurus fulvius and Micruroides euryxanthus)

Pit Vipers (continued)

The signs of envenomation by a pit viper are severe burning pain at the site of the injury, followed by swelling and a blue discoloration (ecchymosis) in light-skinned people that signals bleeding under the skin. Other systemic signs, which may or may not occur, include weakness, nausea, vomiting, sweating, seizures, fainting, vision problems, changes in LOC, and shock. If swelling has occurred, use a pen to mark its edges on the skin. This will allow physicians to assess the timing and extent of the swelling with greater accuracy. If the patient has no local signs an hour after being bitten, it is safe to assume that envenomation did not take place. The toxicity is related to the amount of toxin injected. A bite will affect children more than adults because there is less body mass to absorb the toxin. The same principle holds true for a small-statured adult.

diving reflex

The slowing of the heart rate caused by submersion in cold water.

core temperature

The temperature of the central part of the body (eg, the heart, lungs, and vital organs).

Signs and Symptoms of Hypothermia

To assess the patient's core body temperature (CBT), pull back on your glove and place the back of your hand on the patient's skin at the abdomen. If you work in a cold environment, and/or depending on local protocols, you may carry a hypothermia thermometer, which registers lower core temperatures. It must be inserted in the rectum for an accurate reading. Regular thermometers will not register the temperature of a patient who has significant hypothermia. If the skin feels cool, the patient is likely experiencing a generalized cold emergency.

Wear the appropriate clothing for the environment

To avoid heat loss in cold environments, wear layers of clothing that provide good insulation, such as wool, down, and synthetic fabrics. Protective clothing traps perspiration and prevents evaporation, which prevents cooling. Keep the head, hands, and feet covered, and remove wet clothing if possible. To encourage heat loss in hot environments, wear lightweight, loose-fitting clothing, particularly around the head and neck.

General Management of Cold Emergencies

To prevent further damage to the feet, do not allow the patient to walk. Remove any wet clothing and place dry blankets over and under the patient. If available, give the patient warm, humidified oxygen if you have not already done so. Rough handling of a patient with moderate to severe hypothermia may cause the heart to go into ventricular fibrillation, which may not respond to defibrillation. Do not massage the extremities. Do not allow the patient to eat or to use any stimulants, such as coffee, tea, soda, or tobacco products. Stimulants are vasoconstrictors, which may further impair circulation to affected areas. If the patient is alert, is shivering, responds appropriately, and has a core body temperature is between 90°F to 95°F (32.2°C to 35°C), the hypothermia is mild. Begin passive rewarming slowly, which includes placing the patient in a warm environment; removing wet clothing; and applying heat packs or hot water bottles to the groin, axillary, and cervical regions. Turn the heat up high in the patient compartment of the ambulance. Do not place heat packs directly on the skin. You may give warm fluids by mouth, as allowed by local protocols, assuming that the patient is alert and can swallow without difficulty. When the patient has moderate or severe hypothermia, active rewarming is best accomplished in the emergency department (ED). Therapies might include warm intravenous fluids, lavage with warm fluids, and rewarming blood outside the body before reintroducing it (extracorpeal rewarming). Rewarming the patient too quickly may cause a fatal cardiac dysrhythmia or other significant complications. For this reason, local protocols may dictate the appropriate type of rewarming strategies based on the patient's core body temperature. Your goal is to prevent further heat loss. Remove the patient immediately from the cold environment, place the patient in the ambulance, remove wet clothing, cover the patient with blankets, and transport.

If the core temperature continues to fall to 80°F (26.7°C):

Vital signs slow. The pulse becomes slower and weaker. Respirations become shallow or absent. Cardiac dysrhythmias may occur as blood pressure decreases.

Reassessment

Watch your patient's condition carefully for deterioration. Remove the patient as quickly as possible from the hot environment. Patients with heat cramps or exhaustion usually respond well to passive cooling and fluids by mouth. Patients with symptoms of heat stroke should be transported immediately in a cool ambulance, passively cooled with clothing removal, and actively cooled by spraying the patient with water and fanning to enhance evaporation. Any decline in LOC is an ominous sign. Monitor the patient's vital signs at least every 5 minutes. Evaluate the effectiveness of your interventions. Be careful not to overcool the patient. Inform the ED staff and document the environmental conditions and the activities the patient was performing prior to the emergency in your patient care report.

Resuscitation efforts

When a person is submerged in water that is colder than body temperature, heat will be conducted from the body to the water. The resulting hypothermia can protect vital organs from the lack of oxygen. In addition, exposure to cold water will occasionally activate certain primitive reflexes, which may preserve basic body functions for prolonged periods. Whenever a person dives or jumps into very cold water, the diving reflex may cause immediate bradycardia. Loss of consciousness and drowning may follow. The person may be able to survive for an extended period of time under water, thanks to a lowering of the metabolic rate associated with hypothermia. Local protocols often dictate that resuscitative efforts continue for up to 1 hour after submersion, while simultaneously rewarming the patient. Resuscitative efforts are not initiated for unwitnessed drowning victims who are found in a state of decomposition.

Emergency Care for Drowning or Diving Emergencies

When necessary, begin artificial ventilation as soon as possible, even before the victim is removed from the water. Spinal immobilization must continue while artificial ventilation is performed. If the patient is not breathing, clear any vomit from the airway manually or with suction and assist ventilations with a BVM or pocket mask. Rolling patients onto their side or performing abdominal thrusts will not remove water from the lungs and should not be done unless the airway is obstructed. Frothy sputum in the patient's airway does not require removal with suctioning. When resuscitating a patient who has drowned, the usual CAB order (compressions, airway, breathing) is not used. Rather, address airway and breathing concerns first, then begin compressions and use the AED. If the patient is breathing spontaneously, but has been submerged, administer oxygen. Use pulse oximetry to titrate oxygen delivery according to local protocols. Treat all drowning patients for hypothermia by removing wet clothing and wrapping them in warm blankets. When treating conscious patients who are suspected of having an air embolism or decompression sickness from scuba diving, follow these accepted treatment steps: Remove the patient from the water. Try to keep the patient calm. Administer oxygen. Consider the possibility of pneumothorax and monitor the patient's breath sounds for development of a tension pneumothorax. Provide prompt transport to the ED or to the nearest recompression facility for treatment based on local protocols.

The fangs of the pit viper normally lie flat against the roof of the mouth and are hinged to swing back and forth as the mouth opens.

When the snake strikes, the mouth opens wide and the fangs extend to penetrate whatever the mouth strikes. The fangs are actually special hollow teeth connected to a sac containing a reservoir of venom, which in turn is attached to a poison gland. The gland itself is a specially adapted salivary gland, which produces enzymes that digest and destroy tissue.

Hyperthermia

is a high core temperature, usually 101°F (38.3°C) or higher. High air temperature can reduce heat loss by radiation. High humidity reduces heat loss through evaporation. Older people, newborns, and infants exhibit poor thermoregulation. Alcohol and certain drugs, including medications that dehydrate the body or decrease the ability of the body to sweat, also make a person more susceptible to heat emergencies. When treating someone for a heat emergency, always obtain a medication history.

Drowning

is the process of experiencing respiratory impairment from submersion or immersion in liquid. Major risk factors for drowning include: Alcohol consumption Preexisting seizure disorders Geriatric patients with cardiovascular disease Unsupervised access to water Young children can drown in as little as 1 inch (3 cm) of water if left unattended. Inhaling very small amounts of either fresh or salt water can severely irritate the larynx, sending the muscles of the larynx and the vocal cords into spasm (laryngospasm). Laryngospasm prevents more water from entering the lungs. In severe cases such as water submersion, the patient's lungs cannot be ventilated because significant laryngospasm is present. Progressive hypoxia occurs until the patient becomes unconscious. At this point, the spasm relaxes, making rescue breathing possible. If the patient has not already been removed from the water, the patient may now inhale deeply, and more water may enter the lungs.

Ambient temperature

is the temperature of the surrounding environment.

Hypothermia

means "low temperature" and occurs when core temperature falls below 95°F (35°C).