Primary Assessment Study Guide for the EMT Test

Chief Complaint and Life Threats: Part 5

Environmental Emergencies

Concerns during an environmental emergency include identification, assessment, and management. Emergencies may be a result of submersion, temperature, and radiation.

Drowning and Diving Injuries

Drowning and diving injuries can happen at any age and to even the experienced swimmer or diver. In addition, not all of these injuries occur in swimming pools, and many of them happen in fairly shallow water. The EMT needs to understand how drownings occur and the specifics of diving emergencies, spinal injuries, recovery techniques, and resuscitation efforts.

In many cases, drowning persons are discovered without information about how the incident occurred or the length of exposure. Key characteristics to be aware of include water temperature, submersion timeframe, water purity, signs and symptoms, injuries, co-morbidities, medication, and drug or alcohol use.

Observe for other potential hazards related to injuries in and around water. Assess for critical head trauma or bleeding injuries, and signs and symptoms of breath-holding syncope.

Prevention

Community awareness of water safety is the key to prevention. EMTs can assist in sharing this information with the public. Key tactics for prevention include the use of safe water-related equipment and employing trained lifeguards in public places. The installation of appropriate and safe fences around pools, along with the use of the buddy swimming system, also helps prevent many of these accidents. Avoid the use of alcohol, drugs, and narcotics when swimming, boating, diving, and recreating in or near water. There should be a working phone and an AED in areas where public water activities are conducted.

Here is a term to know:

• breath-holding syncope—a type of fainting that occurs when someone holds their breath for an extended period of time

• diving reflex— a response triggered by sudden cold-water exposure, especially to the face. It can cause immediate slowing of the heart rate, known as bradycardia. In some cases, this reaction may contribute to loss of consciousness and drowning.

Temperature Emergencies

There are four factors that impact the patient’s ability to tolerate temperature variations. These variables include: physical condition, age, environmental impacts, and nutrition/hydration.

Here are some terms to know:

• homeostasis—body’s ability to maintain a stable internal environment despite changes externally

• conduction—transmission of electrical signals along a nerve fiber

• ambient temperature—temperature of the surrounding environment

• convection—transfer of heat through the movement of fluids or gases

• evaporation—process by which liquid turns to gas

• radiation—transfer of heat in waves

• respiration—process by which body exchanges gases (O2 and CO2)

Exposure to Cold

The body can be damaged when exposed to extremely cold elements. It can usually handle and self-regulate temperature. It can even tolerate cold to a certain point below the core body temperature for a limited time. Then, continued exposure to cold, below the core body temperature of 95 degrees, begins to cause injury and impact organ and body system functions.

There are various types of local cold injuries. When a part of the body is exposed to very cold temperatures, it may develop a local cold injury. When the skin is frozen and deeper tissue is not, it may cause frostnip and immersion foot, or trench foot. When the body part and deeper tissues freeze, cell damage occurs. The skin looks waxy, firm, or frozen to the touch. It may have blisters and be cyanotic or mottled in color. This condition is considered frostbite.

Here are some terms to know:

• core temperature—temperature of the body’s internal organs

• trench foot—cold-weather injury that occurs when the feet are exposed to prolonged cold, wet, and unsanitary conditions

• frostbite—freezing injury to the skin and underlying tissues caused by exposure to extreme cold

• frostnip—mildest form of cold injury; superficial, reversible freezing of skin without permanent tissue damage

• characteristics of systemic hypothermia—core body temperature drops below 35 degrees Celsius; shivering, confusion, cold and pale bluish skin, arrhythmias, unconsciousness, etc.

Exposure to Heat

The body can also neglect to self-regulate when exposed to extreme heat. Environmental factors, exercise, underlying medical conditions, and substance use may influence heat exposure and the ability to self-regulate in these cases. If the body’s core temperature rises to 101°F, the diagnosis would be hyperthermia.

Types of heat exposure injuries include heat cramps, heat exhaustion, and heat stroke. A person can experience more than one of these types of exposure during a single event.

Here are some terms to know:

• hyperthermia—core body temperature rises above normal (38 degrees Celsius); occurs when heat production exceeds heat loss

• heat exhaustion—heat-related illness that occurs when the body loses excessive water and salt through sweating, leading to an inability to maintain normal core temperature

• heat stroke—life-threatening heat-related emergency in which the body’s core temperature rises above 40 degrees Celsius due to thermoregulatory failure

• heat cramps—mildest form of heat-related illness; caused by loss of electrolytes and prolonged heat exposure

• turgor—elasticity of the skin; reflects hydration status

High Altitude

High altitudes can cause unbalanced pressure between the atmosphere and total gas pressure upon the body’s tissue, fluids, and cavities of the body. This is referred to as dysbarism. A person not accustomed to high altitude may suffer symptoms related to pulmonary and central nervous system problems. The EMT should have the ability to identify and assist in managing these symptoms.

Here are some terms to know:

• dysbarism injury—medical condition caused by changes in ambient pressure

• HAPE—high altitude pulmonary edema; a life-threatening condition that occurs when fluid accumulates in the lungs due to high altitude exposure

• HACE—high altitude cerebral edema; a life-threatening neurological condition caused by swelling of the brain at high altitudes

Lightning

Heat and electricity are generated from lighting. Many lightning injuries occur in large open areas. Persons can be impacted by lightning via indirect or direct strikes. The most common injuries associated with a lightning strike are to the cardiovascular and nervous systems, resulting in respiratory and/or cardiac arrest.

Here are some concepts to know:

• categories of lightning injuries—They are:

  • direct strike—lightning directly hits the person

  • side flash/indirect strike—lightning strikes a nearby object and jumps to the person

  • contact injury—person is touching an object struck by lighting

  • ground current—lightning strikes the ground and travels through the earth

• reverse triage—method used in mass-casualty incidents to prioritize patients who appear to be the least severely injured but are at the highest risk for deterioration

Bites and Venom

Serious medical conditions can result from bites or stings from spiders, bees, wasps, yellow jackets, ants, ticks, scorpions, and snakes. Not all bites and stings are venomous or poisonous. However, many patients experience reactions up to and including immunologic emergencies. The EMT should be aware of minor reactions and how to treat them. Knowledge of common insects and snakes in your jurisdiction helps respond to venomous and poisonous bites and stings.

Here are some terms to know:

• antivenin—antivenom, biological treatment used to counteract the effects of venom from snakes, spiders, or other venomous creatures

• hymenoptera—group of insects which sting and inject venom (bees, wasps, hornets, ants)

• urticaria—hives; skin reaction characterized by raised, itchy welts caused by histamine release

• anaphylaxis—severe, rapid-onset systemic allergic reaction; can be life-threatening and involve multiple organ systems

Marine Animals

Certain types of marine life can cause injuries. An example is the group of coelenterates, including jellyfish. The stings from these types of creatures cause pain, redness, dizziness, headaches, etc.

Here are some terms and concepts to know:

• coelenterates—marine organisms that can sting and inject venom (jellyfish, sea anemones, corals, hydra)

• common marine envenomations—injuries caused by venomous marine organisms

Shock

The EMT needs to know the causes, signs, symptoms, and emergency treatment of shock (hypoperfusion). Shock occurs when organs and tissues cannot receive an adequate flow of blood and oxygen, or perfusion.

Pathophysiology of Shock

Shock is an acute circulatory condition. It occurs because of insufficient tissue perfusion. This insufficiency creates an imbalance in oxygenation throughout the cells and tissues.

Here are some terms to know:

• hypoperfusion—a condition in which blood flow to body tissue and organs is inadequate

• pulse pressure—difference between systolic and diastolic blood pressure

• sphincters—circular muscles that surround and regulate the opening and closing of a passage in the body

Causes of Shock

The cause of shock involves the heart’s inability to adequately pump, inadequate blood volume, or blood vessel patency or function. These conditions could be cardiac arrest, pulmonary embolism (PE), a high volume of fluid loss from diarrhea or vomiting, septicemia, or spinal cord injury.

Here is a concept to know:

• types of shock related to the physiological causes—hypovolemic (low blood volume), cardiogenic (pump failure), distributive (abnormal blood vessel tone), obstructive (physical obstruction of blood flow)

Types of Shock

There are various types and causes of shock. It is important for the EMT to understand the causes of, and differences among, distributive, hypovolemic, cardiogenic/obstructive, neurogenic, psychogenic, septic, and anaphylactic shock.

Here are some terms to know:

• preload, afterload—Preload refers to the initial stretching of the heart’s ventricles at the end of diastole. Afterload is the resistance the ventricles must overcome to eject blood during systole.

• myocardial contractility—intrinsic ability of the heart muscle to contract

• sensitization—process in which the immune system becomes reactive to a specific antigen or allergen

• aneurysm—localized dilation or ballooning of a blood vessel wall, which weakens vessels and increases the risk of rupture

Stages of Shock

There are two stages of shock. During the stages, the body exhibits specific signs and symptoms that indicate the stage of shock or level of compensation.

Here are some terms to know:

• compensated shock—early stages of shock in which the body’s physiological mechanisms maintain adequate perfusion to vital organs

• decompensated shock—stage of shock in which the body’s compensatory mechanisms fail, leads to inadequate tissue perfusion

Patient Assessment

Certain types of shock are not visible, like a fracture or bleeding would be. There are, however, emergency and medical situations and conditions in which a person is at a high risk of experiencing shock. Learn the key identifiers for shock so that early treatment is possible. The patient assessment and management of shock is the same as for other emergencies: scene size-up/MOI, primary assessment, patient history, secondary assessment, and reassessment.

Here is a concept to know:

• normal limits for blood pressure and pulse rate—normal range for systolic BP: 90-120mmHg diastolic BP: 60-80mmHg Heart rate: 60-100 bpm