Unit 11 Environmental Emergencies

What is the range of normal body temperature?

36 to 37.5° C

How does the hypothalamus regulate temperature?

It Compares heat gain and loss to its set temperature point

What are the four ways in which heat is lost from the body?

Radiation, conduction, convection, evaporation

What compensatory mechanism helps increase body core temperature?

Vasoconstriction and shivering

What compensatory body process can decrease core temperature?

Vasodilation and sweating

What is the upper limit of body temperature before tissue damage occurs?

45° C

What is the lower limit of body temperature before tissue damage occurs?

22° C

Atrial ventricular shunting allows blood to move directly from arterial to venous flow. How does this mechanism help the body regulate temperature?

Open shunts allow body heat to dissipate, closed shunts allow heat to be retained

Heat losses that occur at the skin surface are directly controlled by what part of the brain?

The hypothalamus

Transfer of heat through air or a vacuum is called?

Radiation

Conduction

Direct transfer of heat from one molecule to another

Convection

Heat transfer through circulation of air

Evaporation

Water on the skin is converted to Vapor

Insensible perspiration

Water diffusing through the skin independent of sweating

What chemical mediates sweating?

Acetylcholine

This drug can interrupt sweating

Atropine

Heat cramps are caused by?

Salt depletion as fluids lost through sweating are replaced by water alone

Heat exhaustion is caused by what?

The gradual loss of salt and water due to prolonged exertion in a hot environment

What is the treatment for heat exhaustion?

Rest in a cool environment, hydration and salt replacement

What is heat stroke?

Failure of thermo regulation due to an excessive rise in body temperature above 40 degrees Celsius

What is the pathophysiology of heat stroke?

Cytokines are released as cells try to protect the tissue against injury. Local and systemic inflammatory response ensues

What happens to blood pressure during heat stroke?

It is elevated initially, but hypotension develops afterwards

What is the treatment for heat stroke?

Support the vital organs, rapid cooling

What is rhabdomyolysis?

The breakdown of muscle tissue causing myoglobin (a protein) to accumulate in the kidneys

What is drug fever?

Fever caused by o hypersensitivity to a drug

What is malignant hyperthermia?

Uncontrolled skeletal muscle contraction leading to heat generation

What is the pathophysiology of malignant hyperthermia

Abnormal calcium release from the sarcoplasmic reticulum leads to hyper metabolism. High ATP consumption, High oxygen consumption and carbon dioxide production generate heat

What are the signs and symptoms of malignant hyperthermia

Body temperature rises 1° C every 15 minutes, with a steady rise in end title carbon dioxide. Muscle rigidity and cardiac arrhythmia

A core temperature between 32 and 35 degrees Celsius indicates what condition?

Mild Hypothermia

A core body temperature between 28 and 32 degrees Celsius indicates what condition?

Moderate hypothermia

What is the diving reflex?

A reflex that triggers apnea and circulatory shunting to maintain heart brain circulation

What are the signs and symptoms of submersion hypothermia?

Poor coordination, stumbling, slurred speech, decreased respiratory rate, altered level of Consciousness, weak and irregular pulse

What compensatory processes take place during mild hypothermia?

Intense shivering, vasoconstriction, increased heart rate and increased blood pressure

What compensatory processes take place during moderate hypothermia

Decreased shivering, muscle rigidity, decreased heart rate and blood pressure, loss of consciousness below 30° C

What cardiovascular processes take place during hypothermia?

Gradual decline in heart rate and cardiac output, blood pressure increases and then Falls, dysrhythmia leading to ventricular fibrillation, hyperglycemia, increased blood viscosity

What factors contribute to developing hypothermia?

Ambient temperature, wind chill, water temperature, alcohol and drugs, type of clothing, age and health, malnutrition

What is after drop,

Body temperature continues to fall despite warming. Caused by a heat gradient. Cool core transferred to periphery

What is dry drowning?

Hours after a drowning experience, inhaled water damages lung and oxygen carbon dioxide exchange is impaired

How does salt water play a role in drowning?

Salt water is hypertonic to the blood, so the blood is pulled out of the capillary and into the alveoli

How does freshwater contribute to Drowning?

Freshwater is hypotonic to the blood. Water moves into the circulation

What is Boyle's Law?

The volume of a gas is inversely proportional to its pressure

What is Dalton's law?

Total pressure of a mixture of gases is the sum of the partial pressures of all the gases in the mixture

What is nitrogen Narcosis?

The anesthetic effect of nitrogen at high partial pressure causes laughing tingling and behavioral changes while diving

What questions should a paramedic consider when taking a history for a diving injury?

The onset of symptoms, the type of equipment, the water temperature, the number of Dives in 72 hours, the depth and time at the bottom, any complications while diving

What is diving related barotrauma?

Pressure and balance between gas filled body spaces and the external atmosphere during descent

What is pulmonary overpressurization syndrome?

Disorders that occur due to a diver holding their breath during the ascent

What is arterial gas embolism?

Alveoli rupture and air bubbles enter the pulmonary capillaries. Larger bubbles form and travel to the left side of the heart

What are the signs and symptoms of arterial gas embolism?

Rapid onset of one sided weakness, seizures, unresonsiveness, deafness, visual disturbances

Decompression sickness is also called the bends. What is this condition?

Nitrogen dissolved in the blood comes out during the ascent interfering with tissue perfusion and causing chemical changes in the body

What are the signs and symptoms of decompression sickness?

Joint pain, mottled skin, unsteadiness, paraplegia, chest pain, coughing, dyspnea

Acute Mountain sickness involves headache plus one of these symptoms?

Fatigue, GI, dizziness, difficulty sleeping

What is HAPE?

High Altitude Pulmonary Edema

What is HACE?

High altitude cerebral edema

What causes altitude sickness?

Reactions that cause overprofusion to the brain and lungs leading to increased capillary pressure leakage and edema

Superficial frostbite is characterized by these three conditions?

Numbness, white and waxy, surface firmness

Deep frostbite is characterized by these three symptoms

White, yellow-white, mottled or blue white skin, skin is hard, ice crystals may form during rewarming