NRSG258 Principles of Nursing: Surgical - Thermoregulation and Fever

Flashcards about Thermoregulation and Fever

Human thermoregulation

Achieved through precise balancing of heat production, heat conservation, and heat loss.

Average optimal range of body temperature

Considered to be 37°C (35.8°C – 38.2°C range).

Optimal temperature

Required for enzyme reactions within the body that are vital for survival.

Thermoregulation is mediated

Primarily by the hypothalamus, the endocrine system and the sympathetic nervous system.

Peripheral thermoreceptors

In the skin and central thermoreceptors in the hypothalamus and other locations provide information about skin and core temperatures.

If the body temperatures is low or high

The hypothalamus responds by triggering heat production, heat conservation, or heat loss mechanisms.

Hypothermia

Core temperature less than 36°C (96.8°F). Can be classified as mild, moderate, or severe.

Mild Hypothermia

Core body temperature of 34°C to 35°C (93.2°F to 95°F).

Moderate Hypothermia

Core body temperature of 30°C to 34°C (86°F to 93.2°F).

Severe Hypothermia

Core body temperature less than 30°C (86°F).

Heat promoting mechanisms

Constriction of cutaneous blood vessels, increase in metabolic rate, shivering, enhanced release of thyroxine, behavioral modifications.

Behavioral modifications for heat promotion

Putting on warmer clothing, drinking hot fluids, changing posture to reduce exposed body surface, increasing physical activity.

Hyperthermia

The state of elevated body temperature.

Fever

A systemic response to invading microorganisms; commonly occurs during infection and inflammation.

Post-operative fever

Mild temperature elevation may be transient in nature and may arise from the body's response to tissue injury.

Heat loss mechanisms

Dilation of cutaneous blood vessels, enhanced sweating, behavioural modifications.

Behavioral modifications for heat loss

Reducing activity, seeking a cooler environment, using a device to increase convection, wearing light-colored, loose clothing.

Exogenous pyrogens

Endotoxins produced by pathogens.

Endogenous pyrogens

Act on the body’s thermostat- hypothalamus. Release of prostaglandins.

Hypothalamic thermoregulatory center accomplishes heat production by

Inducing shivering and heat conservation through vasoconstriction.

Benefits of Fever

Kills many microorganisms, decreases serum levels of iron, zinc, and copper, prevents viral replication, improves immune response.

Additional benefits of fever

Enhances phagocytosis, increases production of antiviral interferons.

Risks of Fever

Brain damage if sustained temperature > 41°C, death > 43°C, febrile seizures (>39°C).