Environmental Emergencies

There are four factors that affect how a person deals with exposure to a cold or hot environment: physical condition (ill or in poor physical condition), age, nutrition and hydration, and also environmental conditions. There are five ways heat loss occurs in the body and how the rate and amount of heat loss or gain can be modified in an emergency situation. The first is conduction, which is the transfer of heat from a part of the body to a colder object by direct contact. Convection is where cool air moves across the body surface. There is evaporation, which is the conversion of any liquid to gas. There is radiation, which is the transfer of heat by radiant energy. Lastly, respiration, in which body heat is lost as warm air in the lungs is exhaled into the atmosphere and cooler air is inhaled.

There are four general stages of hypothermia, which occurs when the entire temperature of the body falls below 95 degrees F or 35 degrees C. Mild hypothermia occurs when there is shivering, foot stamping, constricted blood vessels, rapid breathing, and withdrawing. There is moderate hypothermia, which is a loss of coordination, muscle stiffness, coma, slow respirations, slow or weak pulse, dysrhythmias, confusion, lethargy, sleepiness, and the progression towards being unresponsive. Severe hypothermia appears like death, cardiac arrest, and the patient is unresponsive. Never assume that a cold, pulseless patient is dead; no one is dead unless they are warm and dead. A common associated injury is frostbite.

To provide emergency care to a patient who has sustained a cold injury, start with the management for hypothermia in the field, which consists of stabilizing the ABCs and preventing further heat loss. Always start with a scene size-up and make sure the surroundings are safe. Next, you should follow with a primary assessment. In this primary assessment, you should make sure to check for altered mental status, which indicates the intensity of the cold injury; use warmed and humidified oxygen if it is available. Also know that there is evidence to support the fact that CPR will increase blood flow to the critical parts of the body. You should also check the pulse for up to 60 seconds.

When rewarming a patient who is experiencing moderate or severe hypothermia, turn the heat up high in the patient compartment of the ambulance. To avoid burns, do not place heat packs directly on the skin. If possible, you may give warm fluids by mouth. With moderate or severe hypothermia, active rewarming is best accomplished in the ED. Rewarming the patient too quickly or from the extremities rather than the core may cause fatal cardiac dysrhythmia or other significant complications. Emergency care in the field should include removing the patient from further exposure to the cold. Also, you should handle the injured part gently and protect it from further injury. Remove any wet or restrictive clothing from the patient, especially over the injured part. Never rub or massage injured tissues, which could cause further damage. Do not re-expose the injury to cold, and remove any jewelry and cover with a dry sterile dressing. Do not allow the patient to walk on frostbite. When immersing the frostbitten part in water, the temperature should be between 104 and 105°F (40 and 41°C); check the water temperature often, stirring the water. Keep in 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, and expect the patient to report severe pain.

There are also heat-based emergencies that are caused by exposure to hot temperatures. Heat cramps are painful muscle spasms that occur after vigorous exercise. The result may be a loss of essential electrolytes from the cells. To treat, remove the patient from the hot environment. Provide high-flow oxygen and rest the cramping muscles. Replace fluid by mouth and cool the patient with cool water spray or mist.

Heat exhaustion is also called heat prostration or heat collapse. There is hypovolemia as the result of the loss of water and electrolytes. Signs are dizziness, weakness, and syncope, signifying a change in level of consciousness with accompanying nausea, vomiting, or headache. Muscle cramping may also be present, including abdominal cramping. Onset occurs while working vigorously or exercising in a hot environment. The skin may be cold and clammy with an ashen pallor. There may be a dry tongue and thirst, with normal vital signs; pulse is often rapid and weak, and diastolic blood pressure may be low. Normal or slightly elevated body temperature of 104°F. To treat, move the patient to a cooler environment. Give oxygen and check blood glucose level. If possible, perform cold water immersion or other cooling measures, place in the supine position, and fan the patient. Give water by mouth, and if nausea develops, secure and transport the patient on his or her left side.

With heatstroke, the first sign is confusion or a change in behavior. Often the patient becomes unresponsive and seizures may occur. The pulse becomes weaker and the blood pressure falls. The patient no longer sweats, and there is a headache with 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, and body temperature above 104°F. To treat, move the patient out of the heat. Set the AC to maximum cooling and remove the patient’s clothing. Apply high-flow oxygen and provide cold water immersion in an ice bath if possible. Spray the patient with cool water and aggressively and repeatedly fan. Exclude other causes of altered mental status and check blood glucose level. Provide rapid transportation and notify the hospital; be careful not to over-cool. Hyperthermia is a high core temperature, usually 101°F (38.3°C) or higher. A good test for dehydration is skin turgor, or the skin’s ability to resist deformation. It is tested by gently pinching skin on the abdomen or back of the hand. Normally the skin will quickly flatten out; if the patient is dehydrated, the skin will remain tented.

Submersion incidents may be complicated by spinal fractures. Assume that a spinal injury exists under the following conditions: if the submersion has resulted from a diving mishap or a fall from a significant height; the patient is conscious but reports weakness, paralysis, or numbness in the arms or legs; or you suspect the possibility of spinal injury despite what witnesses say. Also be aware of the diving reflex, which occurs when a person dives or jumps into very cold water, caused by a slowing of the heart rate, which may result in a loss of consciousness and drowning. Interestingly, this person may be able to survive for longer periods of time under water thanks to a lowering of the metabolic rate associated with hypothermia. CPR resuscitation may continue for up to 1 hour after submersion, while simultaneously rewarming the patient.

Descent problems are caused by the sudden increase in pressure on the body as the person dives deeper into the water. Some body cavities, like the lungs, the sinus cavities, the middle ear, and the teeth, are usually the main problems. There is a special problem that occurs if the tympanic membrane is ruptured while diving, which may result in a loss of balance and orientation that may cause the diver to shoot to the surface and then experience ascent problems. Ascent emergencies can create an air embolism if a diver holds their breath while ascending. Air may enter the pleural space or the mediastinum. Symptoms are blotching, froth, severe pain, dyspnea, dizziness, nausea and vomiting, dysphagia, cough, cyanosis, difficulty with vision, paralysis, and coma, in addition to irregular pulse and cardiac arrest. There is also decompression sickness, which is known as the bends. Generally, air embolism occurs immediately upon return to the surface, and decompression sickness may not occur for several hours. To treat the bends, patients are often placed into a hyperbaric chamber.

High altitudes can cause dysbarism injuries, which is a difference between the surrounding atmospheric pressure and the total gas pressure in various tissues, fluids, and cavities of the body. Central nervous system and pulmonary system effects range from common acute mountain sickness to high-altitude cerebral edema (HACE) and high-altitude pulmonary edema (HAPE). Acute mountain sickness is caused by diminished oxygen pressure in the air at altitudes above 5,000 feet, resulting in diminished oxygen in the blood, or hypoxia. Continuous positive airway pressure may be helpful for a patient with respiratory distress from HAPE.

Lightning is another environmental emergency that can cause severe damage; lightning injuries are categorized as mild, moderate, or severe. Mild lightning injuries occur when there is a loss of consciousness, amnesia, confusion, tingling, and other nonspecific signs and symptoms. Burns, if present, are typically superficial. Moderate strikes cause seizures, respiratory arrest, dysrhythmias that spontaneously resolve, and superficial burns. Severe lightning injuries cause cardiopulmonary arrest. Due to the short duration of lightning strikes, burns are usually superficial and full-thickness burns are rare. 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. Therefore, you should focus your efforts on those who are in respiratory or cardiac arrest. This process is called reverse triage, where focus is placed on those who are in respiratory and cardiac arrest. Reverse triage is different from conventional triage, where such patients would be classified as deceased. When a patient experiences a massive direct current shock, muscle spasms can result in fractures of long bones and spinal vertebrae; therefore, manually stabilize the patient’s head and open the airway with the jaw-thrust maneuver.

There are also animals that need to be taken into account when dealing with animal emergencies. Regarding spider bites, there are only two in the United States that deliver life-threatening bites: the Black Widow and the Brown Recluse. The Black Widow spider bite is sometimes overlooked if the site becomes numb right away. Most bites cause localized pain and symptoms including agonizing muscle spasms. A bite on the abdomen can be confused with peritonitis. The main danger of a widow’s venom is that it can damage nerve tissues because it is neurotoxic. Other systemic symptoms include dizziness, sweating, nausea, vomiting, and rashes. Tightness in the chest and difficulty breathing develop within 24 hours and subside over 48 hours. Because of the high incidence of side effects of the antivenin, it is typically only given to at-risk populations of patients. A Brown Recluse spider’s bite is not neurotoxic but cytotoxic, in which it causes severe local tissue damage. It produces a large ulcer that may not heal unless treated promptly.

Hymenoptera stings (typically those of bees, wasps, yellowjackets, and ants) are painful but not a medical emergency. Remove the stinger with a firm-edged item such as a credit card or tongue depressor. Use ice packs to assist in controlling pain. Anaphylaxis may occur if the patient is allergic to the venom. Hives or urticaria may develop near the site of envenomation. To treat, administer an epinephrine auto-injector. Also be supportive of the airway and breathing.

Snake bites are another concern; however, in the United States, fatalities are extremely rare, with only about 15 per year. Be very aware of scene safety in cases of snake bites because multiple snakes are often present. Venomous snakes all have hollow fangs in the roof of the mouth, typically creating two small puncture wounds usually about 0.5 inches or 1 cm apart, with discoloration and swelling; the patient usually reports pain. Surrounding redness may be from a nonvenomous snake. The signs of envenomation by a pit viper are severe burning pain, followed by swelling and a blue discoloration (ecchymosis). Signs are evident within 5 to 10 minutes and last over 36 hours. The toxin from pit vipers affects the entire nervous system, leading to weakness, nausea, vomiting, sweating, seizures, fainting, vision problems, and changes in level of consciousness, and also shock. Use a pen to mark the edges of the skin to note the extent of the swelling. When treating, calm the patient, locate the bite area, and clean it with soap and water or a mild antiseptic; do not apply ice to the area. If transport to the hospital is to exceed 2 hours, consider a pressure immobilization bandage of the extremity and place it below the level of the heart. Do not give anything by mouth. If bitten on the trunk, keep the patient supine and quiet and transport quickly. Monitor the patient’s vital signs and mark the skin with a pen over the area that is swollen. If any signs of shock develop, place the patient supine and administer oxygen. Take a picture for identification and notify the hospital. If there are no signs of envenomation, place a sterile dressing over the bite and immobilize the injury site, treating it like a deep puncture wound. Coral snakes cause paralysis of the nervous system followed by progressive paralysis of eye movement and respiration.

The only life-threatening scorpion in the US is the Centruroides sculpturatus, found mainly in Arizona and New Mexico. The venom may produce a severe systemic reaction that leads to circulatory collapse, severe muscle contractions, excessive salivation, hypertension, convulsions, and cardiac failure. Ticks carry two infectious diseases: Rocky Mountain spotted fever and Lyme disease. When delayed care is needed, remove the tick using fine tweezers; grasp the tick by the head and pull gently but firmly straight up so that the skin is tented. Cleanse the area and save the tick in a container for testing.

Marine life is also dangerous. When coelenterate envenomation occurs, the following treatment steps apply: 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. Scrape off the remaining tentacles by scraping them with the edge of a stiff object. Pain may respond to immersion in hot water, and if available, immersion in vinegar. Provide transport to the ED.