Question

4. Using your knowledge of metabolism, cellular respiration, and thermoregulation, explain the following statement: "You aren't dead until you are warm AND dead." In your answer, include examples of when this statement would guide medical treatment to trauma victims. Also, explain why medically induced hypothermia is used as a medical treatment. Include an example of when this might be utilized and the benefits at the cellular level.

Answer 1

Hypothermia is defined as a core temperature below 35°C (95°F). The stage of hypothermia is based on core temperature. They are :

●Mild hypothermia – Core temperature 32 to 35°C (90 to 95°F)

●Moderate hypothermia – Core temperature 28 to 32°C (82 to 90°F)

●Severe hypothermia – Core temperature below 28ºC (82°F)

Because the response to hypothermia varies widely among patients, it is classified based on severity, like

●Cold stressed (not hypothermic): Normal mental status with shivering. Functioning normally. Able to care for self. Estimated core temperature 35 to 37°C (95 to 98.6°F).

●Mild hypothermia – Alert, but mental status may be altered. Shivering present. Not functioning normally. Not able to care for self. Estimated core temperature 32 to 35°C (90 to 95°F).

●Moderate hypothermia – Decreased level of consciousness. Conscious or unconscious, with or without shivering. Estimated core temperature 28 to 32°C (82 to 90°F).

●Severe/profound hypothermia – Unconscious. Not shivering. Estimated core temperature <28°C (<82°F).

pathology:

Heat is generated by the metabolic processes that occur within the tissues of the body, such as fat and muscle.

Metabolic rate refers to the rate of heat liberated during these chemical reactions and lost by the skin and lungs by different processes like radiation, conduction, convection, and evaporation.

• Radiation—Loss of heat may occur to surrounding cooler objects in the form of infrared radiation
• Conduction—Heat may be lost to objects close to the skin, such as a chair, a bed, or the floor. Heat may also be lost by conduction to the surrounding air
• Convection—Removal of body heat by air currents
• Evaporation—Heat may be lost by evaporation of water from the body.

mechanism:

The hypothalamus receives input from central and peripheral thermal receptors. In response to a cold stress, the hypothalamus attempts to stimulate heat production through shivering and increased thyroid, catecholamine, and adrenal activity. Sympathetically mediated vasoconstriction minimizes heat loss by reducing blood flow to peripheral tissues, where cooling is greatest .Peripheral blood vessels also vasoconstrict in direct response to cold.

Cooling decreases tissue metabolism and inhibits neural activity. During the initial phase of cooling, shivering in response to skin cooling produces heat and increases metabolism, ventilation, and cardiac output. Neurologic function begins declining even above a core temperature of 35°C. Once the core temperature reaches 32°C, metabolism, ventilation, and cardiac output begin to decline and shivering becomes less effective until it finally ceases as core temperature continues to drop.

MANAGEMENT(medically induced hypothermia as medical treatment)

It is essential to recognize that unless there are obvious lethal injuries, a fatal illness, prolonged asphyxia, or if the chest is incompressible, survivability is possible in a hypothermic.

Passive rewarming

For most patients that are admitted with mild hypothermia, rewarming may be effectively achieved by covering the head and body with warm blankets

Active rewarming

• Forced air rewarming(Bair hugger)blanket
• This system consists of a warming device and single use, disposable, laminate blankets that allow warm air to flow directly onto the patient's skin.
• warm intravenous fluid

other techniques

· Warm humidified oxygen or air

· Peritoneal dialysis or pleural cavity lavage with warm fluids

· Cardiopulmonary bypass for severely hypothermic patients with cardiac arrest.

In trauma victims, the mortality rate among hypothermic is more as compared to normothermal patients .Those particularly vulnerable are burn victims, patients with serious head injuries, or individuals with upper spinal cord injuries affecting the sympathetic chain.