HYPERTHERMIA

 DEFINITION

Hyperthermia is defined as elevated core temperature of greater than 38.5°C  (101.3°F).  Hyperthermia is an umbrella term that refers to several conditions that can occur when body’s heat-regulation system cannot tolerate with the heat in the Environment.

CAUSES OF HYPERTHERMIA

• Increased Environmental Temperatures:
  • Heat Waves: A heat wave is a period of unusually hot weather that typically lasts two or more days
  • Humidity: Humidity is the concentration of water vapor present in the air.  A higher percentage denotes that the air–water mixture is more humid.
• Increased Heat Production (Gain)
  • Overexertion: Exercise Increases the basal metabolism rate of the tissues that fuel up the body and increases the body temperature
  • Thyroid Storm: Thyroid storm is a life threatening condition that increases the secretion of abnormally high thyroid hormones that in turn increases the body’s basal metabolic rate and thereby results in Increased body temperature.
  • Malignant Hyperthermia: Malignant hyperthermia is a life-threatening clinical syndrome of hyper metabolism involving the skeletal muscle triggered in susceptible individuals primarily by the volatile inhalational anesthetic agents this hyper metabolism causes increased heat Production
  • Pheochromocytoma: It is the tumors of the adrenal gland that causes increased catecholamine production which triggers the sympathetic Nervous System to increase the hypothalamus to increase the thermogenic set point causing hyperthermia
  • Delirium Tremens: It is an alcohol withdrawal symptoms where the brain & spinal cord is not able to adjust quickly that results in overstimulation of hypothalamus that leads to hyperthermia
  • Hypothalamic Disorders: Hypothalamus is responsible for the balance in body temperature any dysfunction in hypothalamus can alter the balance in heat production and heat loss that results in hyperthermia
  • Drug Toxicity: Drugs like sympathomimetic Agents, Anti-Cholinergics, Anesthetics & Anti-psychotics can cause toxic effects that can increase the thermogenic set point causing hyperthermia
• Decreased Heat Dissipation (Loss):
  • Decreased Peripheral Vasodilation & poor sweating: Sweating and peripheral vasodilation are major mechanisms of heat loss to maintain proper temperature. In the absence of these mechanisms, baseline temperature from basal metabolism Increases.  Sweat cools the body through evaporation, and peripheral vasodilation provides the blood flow and heat necessary to evaporate the sweat. During periods of high environmental heat and humidity, evaporative cooling can become insufficient, leading to high body temperatures
  • Hot Environment: When the weather is very hot, the body has to work very hard and produce a lot of sweat to keep itself cool. Under some conditions, sweating just isn't enough and a person's body temperature rises rapidly.

STAGES OF HYPERTHERMIA

• Heat Stress: The body temperature starts to raise and when it is unable to cool the body through sweating the body experiences uncomfortably hot called as heat stress.
• Heat Fatigue: While exposed to long hours of high heat causes physical discomfort like feeling hot, thirst tired & inability to concentrate and loose co-ordination. People who aren’t used to extremely hot weather or hot working conditions are especially vulnerable to heat fatigue.
• Heat Syncope: While exposed to long hours of high heat causes physical discomfort like feeling hot, thirst tired & inability to concentrate and loose co-ordination. People who aren’t used to extremely hot weather or hot working conditions are especially vulnerable to heat fatigue.
• Heat Cramps: Heat cramps usually follow intense exertion or exercise in the heat. They’re caused due to electrolyte imbalance and are usually felt in the abdomen, leg, or arm muscles.
• Heat Edema: Heat edema can occur while exposed for a long time in hot temperatures. The swelling occurs in the extremities and Ankles due to accumulation of fluid in response to the aldosterone-stimulated reabsorption of sodium into the blood through the kidneys.
• Heat Rash: Sometimes, being active in the heat for prolonged periods of time can cause red pimple-like bumps to appear on the skin. This usually develops underneath clothing that has become soaked with sweat.
• Heat Exhaustion: This is one of the most serious stages of hyperthermia. Heat exhaustion occurs when body can’t cool itself any more leading to profuse sweating and exhaustion.

CLINICAL MANIFESTATIONS

• Flushed red skin progressing to cold, pale, wet skin
• extreme or heavy sweating
• fast but weak pulse
• nausea, vomiting, and diarrhoea
• Headache or Light headedness
• muscle cramps
• Exhaustion
• weakness
• Intense thirst
• dizziness
• less frequent urination and dark urine
• Difficult concentration & Co-ordination
• Mild swelling of the feet and ankles or fingers and hands
• Temporarily fainting or losing consciousness

TREATMENT OF HYPERTHEMIA

• Move the client to a cool, shaded place with good airflow in case of hyperthermia.
• Seek medical attention if heat cramps last longer than one hour after they have rested in a cool place.

Treatment of mild to moderate hyperthermia include:

• Provide oral fluid like water or Electrolyte drink to prevent Dehydration
• Loosen or remove excess clothing to promote heat loss
• Provide Adequate bed rest and allow the client to relax and be comfortable
• Cold compressors are provided by placing cool wet cloth on the forehead, axilla and soles when temperature rises above 100⁰F
• Provide tepid sponging when temperature is above 103⁰F
• Open windows & doors and switch on fans for ventilation &cooling the skin
• placing ice packs or cold compresses under the arms and groin when temperature rises more than 104⁰F

HEAT STROKE

Heatstroke is a condition caused by your body overheating, usually as a result of prolonged exposure to or physical exertion in high temperatures. This most serious form of heat injury, heatstroke, can occur if your body temperature rises to 104 F (40 C) or higher.

Heatstroke requires emergency treatment. Untreated heatstroke can quickly damage brain, heart, kidneys and muscles. This damage increases the risk of serious complications or death.

CLASSIFICATION OF HEAT STROKE

• Non-Exertional Heat Stroke: In this type of heatstroke, there is a rise in core body temperature that typically occurs after exposure to hot, humid weather, especially for prolonged periods. It occurs most often in older adults and in people with chronic illness.
• Exertional Heat Stroke: This is caused by an increase in core body temperature due to intense physical activity or exercising in hot weather & it's most likely to occur when the person not used to high temperatures.

CAUSES & RISK FACTORS OF HEAT STROKE

• Age: The ability to cope with extreme heat depends on the function of central nervous system. In the very young, the central nervous system is not fully developed, and in adults over 65, the central nervous system begins to deteriorate, which makes the body less able to cope with changes in body temperature making them difficult to remain hydrated.
• Sudden Exposure to hot weather: During sudden exposure to hot weathers in early-summer heat wave or travel to a hotter climate makes the person more susceptible to heat related Illness
• Physical Exertion: Participating in Sports, Military training & athletics in hot weather can cause Heat Stroke
• Lack of Cooling Devices: Lack of cooling devices like air conditioning and fans during hot weather can cause dehydration & Heat Stroke
• Medications: Certain Medications like beta blockers, Vasoconstrictors, diuretics, Anti-depressants & Anti-Psychotics affects the body’s ability to stay hydrated & respond to heat and makes the person vulnerable to heat stroke
• Health Condition & Illnesses: Certain chronic illnesses, such as heart or lung disease, Being obese & sedentary lifestyle might increase risk of heatstroke.

SIGNS & SYMPTOMS OF HEAT STROKE

• High body temperature. A core body temperature of 104 F (40⁰C) or higher, is the main sign of Heat Stroke.
• Altered mental state or behaviour.
• Confusion, agitation, slurred speech, irritability, delirium, seizures and coma can all result from heatstroke.
• Alteration in sweating.
• Skin will feel hot and dry to the touch and moist Nausea and vomiting.
• Flushed skin. skin may turn red as body temperature increases.
• Tachypnea : Rapid breathing
• Tachycardia : Increased heart rate
• Headache

DIAGNOSTIC FINDINGS OF HEAT STROKE

• Temperature Assessment: Temperature is usually more than 104⁰F
• Blood Test: Sr. Electrolytes like Sodium & Potassium are deranged in case of dehydration
• Urine Test: Urine color is darker in heat related disorders due to Increased Urine Concentration
• X-ray & Imaging Studies: To Check damage to the Internal Organs

TREATMENT OF HEAT STROKE

• Clothing: Wear light fitting & loose clothing to allow the body to cool properly
• Sunburn Protection: protect the body in outdoors with a wide-brimmed hat and sunglasses and use a broad-spectrum sunscreen with an SPF of at least 15. Apply sunscreen generously, and reapply every two hours — or more often if you're swimming or sweating.
• Fluids: Drink plenty of Fluids or IV Fluids & Maintain a normal body Temperature. While exercising in hot weather keep hydrated regularly with fluids
• Cold Sponging: A bath of cold or ice water has been proved to be the most effective way of quickly lowering your core body temperature. The quicker cold water sponging is done, the less risk of death and organ damage.

PHARMACOLOGIC MANAGEMENT

• Antipyretics like Acetaminophen to decrease body temperature
• Muscle relaxants like Dantrolene to treat life threatening heat Stroke & Malignant Hyperthermia
• Non steroidal Anti-Inflammatory drugs like Ibuprofen to treat pain and fatigue

PREVENTION OF HEAT STROKE

• The risk of heat stroke can be reduced by observing precautions to avoid overheating and dehydration.
• Loose-fitting clothes will allow perspiration to evaporate and cool the body.
• Light color clothing help prevent the sun from warming the head and neck.
• Strenuous exercise should be avoided during hot weather, especially in the sun peak hours as well as avoid spaces without air-conditioning or adequate ventilation.
• Drink plenty of cool liquids and mineral salts to replace fluids lost from sweating.
•   Block out direct sun and other heat sources.
• Avoid beverages containing alcohol or caffeine.
• Avoid outdoor sports & replace with Indoor sports in case of extreme hot temperatures