Thermoregulation

Thermoregulation

Unit 4

Module 4B

Jill Huffman, MSNed, RN

Learning Outcomes

• Identify common assessment techniques used to examine thermoregulation across the lifespan.

• Identify how thermoregulation is related to the aging process.

• Use clinical judgment to plan care for patients with alterations in thermoregulation across the lifespan.

Learning Resources

• Ignatavicius, D. (2021). pp. 207–209 & 216-217.

• Ignatavicius, D. (2021). Chapter 11 (questions 1-7 & 27-30).

Heat-Related Illnesses

• The most common environmental factor causing heat-related illnesses is the high environmental temperature (above 95° F) and humidity (above 80%).

• Can cause heat exhaustion and heat stroke

• The most vulnerable, at-risk populations are:

• Older adults – have less body fluid volume and can quickly become dehydrated

• Mental health/behavioral health conditions

• Those who work outside

• Homeless

• Substance abuse

• Athletes who engage in outdoor sports

• Military members who are stationed in hot climates

Heat-Related Illnesses

• Risk Factors:

• Obesity

• Heart Disease

• Fever

• Infection

• Strenuous Exercise

• Seizures

• Mental Health Disorders

• All degrees of burns (including sunburn)

• Some prescription medications such as lithium, neuroleptics, beta-blockers, anticholinergics, ACE inhibitors, and diuretics

Heat-Related Illness Prevention

• Avoid alcohol and caffeine

• Prevent overexposure to the sun; use sunscreen with an SPF of at least 30 with UVA and UVB protection

• Rest frequently and take breaks from being in a hot environment. Avoid the hottest part of the day

• Wear lightweight, light-colored, and loose-fitting clothing

• Pay attention to personal physical limitations

• Take a cool bath or shower to help reduce body temperature

• Stay indoors in air-conditioned buildings or in a shaded area as much as possible

• Check on older adults at least twice a day during a heat wave

Heat Exhaustion

• Defined as a syndrome resulting primarily from dehydration

• Caused by heavy perspiration and inadequate fluid and electrolyte intake during exposure to heat

• Hyponatremia is caused by excessive sodium loss in perspiration

• If left untreated can lead to heat stroke

S/S of Heat Exhaustion

• The patient may have flu-like symptoms including:

• Headache

• Weakness

• Nausea

• Vomiting

• Body temperature may not be elevated

• The patient may continue to perspire despite being dehydrated

• Assess the patient for orthostatic hypotension and tachycardia

• Older adults may experience acute confusion

• Increased risk of falls

Treatment of Heat Exhaustion

• Stop physical activity and move to a cool place

• Place cold packs on the neck, chest, abdomen, and groin

• Soak in cool water or sit in front of a fan while spraying water on the skin

• Remove constrictive clothing

• Drink sports drinks (plain water can worsen the sodium deficit)

• Monitor vital signs

• IV solutions as ordered if nausea and vomiting persist

• Labs for serumDrugs may not be given until the core temperature is above 86°F (30°C). Defibrillation may not be effective until the core temperature is above 86°F (30°C) if cardiac arrest occurs. Active and core rewarming methods should be used. After-drop, which is the continued decrease in core temperature after the victim is removed from the cold environment due to cold blood returning from the periphery, should be monitored. Nursing care for severe hypothermia is similar to that of moderate hypothermia. Extracorporeal rewarming methods such as cardiopulmonary bypass or hemodialysis should be used. Complications related to rewarming, such as fluid, electrolyte, and metabolic abnormalities, acute respiratory distress syndrome (ARDS), renal failure, and pneumonia, should be monitored. Patients are not considered dead until they are warmed and reevaluated.

Frostbite occurs when body tissue freezes and causes damage to tissue integrity. It can be a superficial, partial, or full-thickness cold-related injury that may or may not be related to hypothermia. Frostnip is a superficial cold injury that produces pain, numbness, and pallor or a waxy appearance of the affected area but is easily relieved by applying warmth. The main risk factor for frostbite is inadequate insulation against cold weather. Grades of frostbite include Grade I (least severe), Grade II, Grade III, and Grade IV (most severe).

Recognition of frostbite is essential to early intervention and prevention of further damage to tissue integrity. Superficial frostbite can be managed by using body heat to warm the affected areas, such as placing hands under arms to warm. For all degrees of partial-thickness to full-thickness frostbite, rapid rewarming in a water bath at a temperature of 99°F to 102°F (37° to 39°C) is indicated to thaw the frozen part. Treatment for frostbite includes administering opioid pain medications as prescribed, administering IV fluids as ordered, Ibuprofen to decrease inflammation, and elevating the area above the heart to decrease edema once rewarming is complete. The affected area should be handled gently to prevent further damage, and splints should be applied as ordered. Compartment syndrome is a painful condition that occurs when pressure within the muscles builds to a dangerous level. Symptoms include sudden pain, tightness, numbness and tingling, and swelling. Treatment consists of emergency surgery to relieve the pressure (fasciotomy).