Thermoregulation Lecture Notes PDF

# Thermoregulation Lecture Notes - **Thermoregulation** is constantly maintaining a stable core body temperature. - **Normothermia** (36.2°C-37.6°C). - **Hypothermia** (Below 36.2°C). - **Mild** (34°C-36.2°C) - **Moderate** (30°C-34°C) - **Severe** (30°C) - **Hyperthermia** (Above...

# Thermoregulation Lecture Notes - **Thermoregulation** is constantly maintaining a stable core body temperature. - **Normothermia** (36.2°C-37.6°C). - **Hypothermia** (Below 36.2°C). - **Mild** (34°C-36.2°C) - **Moderate** (30°C-34°C) - **Severe** (30°C) - **Hyperthermia** (Above 37.6°C-41.5°C) - **Hyperpyrexia** is extremely high body temperature (41.5°C) - **Fever** is a rise in the body temperature due to a change in the hypothetical setpoint due to foreign antigens (e.g. pyrogens) - **Temperature Balance** (What are the factors/things that affect the body's heat production?) - **Basal Metabolic Rate** is the rate of energy the body uses to maintain essential activities such as breathing - Can either increase or decrease the body heat production. - Metabolic rates decrease with age, the younger in age, the higher the metabolic rate. - **Muscle Activity** (e.g. shivering) to produce heat. - **Thyroxine output** (hormone produced by the thyroid gland and is crucial in regulating metabolism). - Increase thyroxine levels is increased Epinephrine (hormone & neurotransmitter). - **Epinephrine, Norepinephrine and Sympathetic Stimulation/Stress Response** - Epinephrine and norepinephrine are hormones and neurotransmitters that increases the rate of metabolism and causes vasoconstriction that increases body temperature. - **Fever** - **4 Methods of Heat Loss** - **Convection**: heat transfer from warm to cool air. - **Conduction**: direct contact heat transfer from warm to cooler surface. - **Radiation**: heat transfer from warm to cooler objects close by without direct contact. - **Evaporation**: heat transfer from water droplets to vapor (sweat, baby getting out of the bath, etc.). - **Fahrenheit-Celsius Conversion Formula** is F=1.8C+32 ## Assessment of Thermoregulation ### Exam Findings - *Symptoms vary* - **Vital signs** (**temperature**) ### Diagnostics - CBC (to detect infection) - Electrolyte panels (assess for imbalances) - Urinalysis (to detect dehydration) - Imaging (for underlying causes) ### History - Age - **Family History** (**screening for hx of Malignant Hyperthermia**) - Health History - Exposure (length and type of exposure) ## Prevention of Thermoregulation ### Primary Prevention - Focused on reducing the risk. - Environmental control/shelter. - Appropriate clothing. - Physical activity - Prepared for the conditions that they are going to be doing physical activity in. ### Secondary Prevention (Screening) - Malignant Hyperthermia ### Tertiary Prevention - Minimizing complications ## What is the Hypothalamus role? 3 Primary Components of the Hypothalamus: 1. **Sensors** - Most sensory receptors are in the skin and detect cold more efficiently than warmth. - The sensors are mediated by the hypothalamus through neurological and hormonal control. 2. **Hypothalamus** 1. Once the sensors detect a change, they will send a signal to the Hypothalamus, which will stimulate the pituitary gland to release thyroid stimulating hormone (TSH) Thyroxine (T4) 2. Thyroxine (T4) will then stimulate the adrenal gland to release Epinephrine (neurotransmitter and hormone) which stimulates glycolysis (breakdown of glycogen to glucose), causes vasoconstriction and increases the metabolic rate to stimulate heat production. - The Hypothalamus will also send hormones to the sympathetic nervous system to cause shivering and increase muscle tone. 3. **Effector** (what is affected by the hypothalamus). - Once the body temperature is within normal range, the Hypothalmus will stop sending signals to release hormones and the sympathetic nervous system will begin to vasodilate (relaxing the muscles & blood vessels) so that the body can stop shivering and start sweating. ## Risk Factors of Thermoregulation - **Age** (old and very young) - **Infants** - Can't conserve heat. - They don't shiver. - They have a large body surface area. - Low subcutaneous fat. Instead of having subcutaneous fat, they have Brown Fat (nonshivering thermoregulation-NST). - Blood vessels are close to the skin. - Infants will curl up in the fetal position to maintain & regulate heat, but if preterm the babies may not have the muscle ability to curl up into a fetal position which increases loss of temperature. - **Elderly** - Less effective thermoregulatory response. - Decrease perception of hot/cold (skin sensors are as effective) - **Racial disparity/Social determinants** - **Alcohol consumption** - **Medical conditions** (post-op surgery, CHF, muscular skeletal issues, diabetics, TBI) - **Homeless population** - **Financial status/issues** - **Mental health conditions** - **Individuals who work and play sports outside** ## Interrelated Concepts ### Infection - Most bacteria & virus thrive at 98.6 - Hand hygiene ### Perfusion - Vasodilation - Vasoconstriction ### Intracranial Regulation - Traumatic Brain Injury ### Tissue Integrity - Skin barrier? Intact? ### Nutrition - Patients with malnutrition are at an increased risk. ### Fluid & Electrolytes - Monitor I&O for dehydration or electrolyte imbalance ## Hypothermia ### Assessment - Vasoconstriction causes Cool & clammy - Pale - Slow capillary refill - Muscle rigidity & shivering. - Shivering will disappear when the temp reaches 30°C/86°F - As the temperature continues to decrease: - Poor perfusion - Cognition changes due to low oxygenation to the brain (93.2F/34C). - Coma - Decreased urinary output. - Dysrhythmias, leading to cardiovascular collapse. ### Prevention Strategies - Wear appropriate clothing. - Moisture wicking clothes. - No alcohol consumption. - Adequate nutrition. - Help with the metabolism of the body. ## Hyperthermia ### Assessment - **Tempertature** (but an entire assessment of vital signs is still warranted) - Appear flushed due to vasodilation. - Skin warm or hot to touch. - Appear diaphoretic (sweaty, clammy, or flushed). - Showing signs of dehydration: - Decreased urinary output. - Dry skin & mucous membranes. - As the temperature continues to increase: - Decreased cognition. - Seizures. - Coma. ### Risk Factors - Dehydration ## Autoimmune disorders ## Certain medications ### Prevention Strategies - No alcohol consumption. - Wear sunscreen at least 30 SPF. - Wear appropriate clothing (light colors). ### Secondary Prevention: **SCREEN FOR MALIGNANT HYPERTHERMIA** ## Clinical Judgment The 6 functions of clinical judgment | Function | Question | |:--------------------|-------------------------------------------------------| | Recognize cues | What matters most? | | Analyze cues | What does it mean? | | Prioritize hypotheses | Where do I start? | | Generate solutions | What can I do? | | Take action | What will I do? | | Evaluate outcomes | Did it help? | The Nursing Process: ADPIE/AAPIE (Assessment, Analyze Cues, Planning, implementing, Evaluation) Clinical judgment: Recognize cues, Analyze cues, Prioritize hypotheses, Generate solutions, Evaluate outcomes Combining Clinical Judgment & Nursing Process -Assessment (Recognizing cues) -Analyze (Analyze cues) -Planning (Prioritize hypotheses) -Implementation (Generate solutions) -Evaluation (Take action & Evaluate outcomes) ## Hypothermia S/S and Interventions ### Mild (90°F to 95°F [32°C to 35°C])S/S - Shivering - Blood pressure increases (due to vasoconstriction and the blood is flowing to the central circulation/central part of the body (eg.heart, lungs, kidneys, liver)) - However, mild hypothermia can display as high and low blood pressure b/c as your blood volume starts to drop due to vasoconstriction and focusing on those central circulation/major organs, the blood volume in the periphery of your body (arms, hands, legs, feet) also drops; so, you may not be able to detect blood pressure. - As the body warms up, vasodilation of the periphery can cause Diuresis (all the blood from the peripheral/sides of the body is now being shunted back to the central/major organs and the blood is being filtered fast). - Need to be concerned about dehydration because now the individual has issues with controlling urination and is losing more fluid because the kidney may be overstimulated from the blood coming back from the peripheral to the central body. - Increase in heart rate. - Respirations elevated. ### INTERVENTIONS - **Remove wet clothing** - **Warm blankets** - **Warm oral fluids** ### Moderate (82.5°F to 90°F) [28°C to 32°C]) S/S - Altered Mental Status (Confused, Appear to be drunk, etc.) - Decreased clotting ability (caused by impaired platelet aggregation and thrombocytopenia) ### INTERVENTIONS - Warm IV Fluids *Do not rewarm too quickly (could cause cardiac arrest and the body is not metabolizing as quickly when the body is cold; so when the body is warmed to **WARM THE CORE OF THE BODY FIRST!!!!** ### Severe (Below 82.4°F [28°C]) S/S - Severe hypotension (if you can attain a BP) - SPO2 drastically low (if detectable) - May lose extremities due to no blood flow to periphery (frostbite) ### INTERVENTIONS - Remove Wet Clothing - Monitor urinary output w/ urinary catheter - Great indicator of perfusion, low urine output is indicative of low/bad perfusion - Continue to attempt to resuscitate them until they are warm **They are not dead until they are warm and dead**