Thermoregulation Notes

Thermoregulation

This note covers thermoregulation, including normal body temperature, factors affecting it, hypothermia, hyperthermia, their signs and symptoms, and interventions.

Normal Body Temperature

• Average body temperature:
  • $37^\circ C$
  • $98.6^\circ F$
• Normal range:
  • $36.2^\circ C$ - $37.6^\circ C$
• Normothermia: Body temperature within the normal range.

Factors Affecting Body Temperature

• Metabolic rate
• Optimal body function
• External factors, such as weather and clothing
• Physiological factors:
  • Blood loss
  • Sleep deprivation
  • Diet
  • Smoking
  • Exercise

Hypothalamus

• The hypothalamus maintains the baseline thermostat.
• Shivering is a physiological response to increase body temperature when cold.

High and Low Body Temperatures

• Extreme high body temperature: above $41.5^\circ C$.

Populations with Less Efficient Thermoregulation

• Old age:
  • Less efficient due to physiological function decline.
  • Reduced circulation.
  • Reduced vasoconstriction response.
  • Diminished shivering response.
• Babies:
  • Slower metabolic rate.
  • Not as active.

Hypothermia

• Common factors:
  • Alcohol/drug use (vasodilators)
• Nursing Process:
  • Assessment
  • Diagnosis
  • Planning
  • Implementation
  • Evaluation

Assessment

• Age
• Alcohol/drug use
• Recent illness/injuries
• Exposure duration and severity
• Symptoms:
  • Body aches
  • Fever
  • Lethargy
  • Dizziness
• Blood Pressure/Hydration

Signs and Symptoms of Hypothermia

• Shivering
• Pale skin
• Cyanosis
• Confusion
• Slurred speech
• Slow capillary refill

Signs and Symptoms of Hyperthermia

• Flushed skin
• Sweating
• Dehydration
• Decreased HR

Hydration Assessment

• Mucus membranes: pink and moist indicate hydration.
• Skin less than 2 seconds indicates hydration.

Goals

• Tailor goals to each patient.
• Goal: Bring the patient back to the normal temperature range.

Hyperthermia Interventions

• Cooling blankets
• IV meds
• Tylenol/Ibuprofen

Evaluation

• Did the care plan work?
• How to evaluate?

Interrelated Concepts

• Perfusion
• Infection
• Intracranial Regulation
• Thermoregulation
• Tissue Integrity
• Nutrition
• Fluid and Electrolytes

Conditions

• Hypothermia
• Hyperthermia

Signs and Symptoms of Hypothermia

• Slow capillary refill
• Pale, cyanotic skin
• Shivering, rigidity
• Dysrhythmia
• Body heat drop
• Slurred speech
• Poor coordination
• Slow heart rate
• Difficulty finding pulse

Consequences of Hypothermia

• Late symptoms:
  • No shivering
  • Blue skin
  • Slowed pulse/breathing
  • Loss of consciousness
• Frostbite

Interventions for Hypothermia

• Warming blankets
• Warm clothes
• Warm IV fluids
• Inhaling warm oxygen

Pathophysiology of Hyperthermia

• Temperature elevation
• Sweating
• Red, flushed skin
• Vasodilation
• Lightheadedness
• Lower BP
• Increased HR
• Dry mucus membranes
• Dehydration

Consequences of Hyperthermia

• Cardiovascular collapse
• Heat exhaustion
  • Faint or dizzy
  • Excessive sweating
  • Nausea or vomiting
  • Muscle cramps
  • Rapid, weak pulse
  • Cool, pale, or clammy skin
• Heat stroke
  • Headache
  • No sweating
  • Nausea or vomiting
  • Rapid, strong pulse
  • Body temperature above $103^\circ F$ or $39^\circ C$
  • Unconsciousness
• Health complications
  • Renal failure
  • Pulmonary edema
  • Heart dysfunction
  • CNS dysfunction
  • Liver failure
  • Intravascular coagulation

Interventions for Hyperthermia

• Hydrate
• Remove excess clothing and blankets
• Provide external cool packs
• Provide a cooling blanket
• Hydrate with cool fluids (oral or intravenous)
• Lavage with cool fluids
• Administer antipyretic drug therapy

Physiological Responses

• Fast blood flow = fast heart rate, fast breathing, high blood pressure
• Slow blood flow = slow heart rate, slow breathing, low blood pressure