EMER 199 Medical 3 Flashcards
Thermoregulation
Heat production and excretion
Hypothalamus
thermostat of the brain
afferentefferent
Skin to nervous system afferent pathways Hypothalamus to body efferent pathways
Lowest temp a human can survive
is 13.7
hypothermia vs hyperthermia
Hyperthermia Vasodilation (increased HR) Hairs flat Sweat – dermal layer of skin Hypothermia Vasoconstriction Piloerection Shivering
Thermolysis
release of stored heat Mediated by parasympathetic nervous system
An increase in core temperature causes
the hypothalamus to send signals via Efarrant pathways in the parasympathetic nervous system causes vasodilation and sweating
Body’s reaction to daily production of heat energy and to hot environment
Vasodilation: The person may have a complete loss of vasomotor control blood pools in the periphery and the patient could experience distributive shock
Radiation
body heat is lost to nearby objects without physically touching them (heat waves- sun)
Conduction
body heat is loss to nearby objects through direct physical touch (touch)
Convection
body heat is lost to surrounding air which becomes warmer, rises abd is replaced with cooler air (air moving over- an object-fan)
Evaporation
body heat causes precipitation which is lost from the body surface when changed from liquid to vapor (sweating)
Thermogenesis
Production of heat and energy for the body Mediated by the sympathetic nervous system
Main method of dealing with cold stressors
Skin is the body’s thermostat. Increases muscle tone and initiate shivering in the short term Increases thyroid levels in the long term Hypothalamus shunts blood to the core. Sweating decreases.
Heat Illness
Increase in core body temperature –Due to inadequate thermolysis –Inability to get rid of the heat buildup in the body
Heat Cramps
Acute involuntary muscle pains Usually in the lower extremities, the abdomen, or both Occur because of profuse sweating and subsequent sodium loss 3 factors contribute: salt depletion, dehydration and muscle fatigue
Heat Cramps Treatment
Stop activity Move the patient to a cool environment. If the patient is too nauseated to take liquids by mouth, insert an IV catheter and infuse normal saline rapidly. Do not massage the cramping muscles.
Heat Syncope
Typically occurs in nonacclimated people Can occur with prolonged standing or when standing suddenly from a sitting or lying position Peripheral vasodilation is thought to be the cause. Treatment involves placing the patient in a supine position and replacing fluid deficits.
Water depleted
This form primarily effects geriatric patients. Can effect active younger workers and athletes who do not adequately replace fluids in a hot environment
Sodium Depleted
May take hours or days to develop Results from huge sodium losses from sweating but replacing only free water
Heat Cramps s/s
Temp < 40 No alt LOC sweating Headache, fatigue, dizziness, nausea, vomiting, and, sometimes, abdominal cramping Skin is pale and clammy. Fast and shallow respirations Tachypnea
Rhabdomyolysis
muscle breaks down releases potassium which can kill you (brown urine)
“Summer flu”
Misdiagnosed If untreated may progress to heat stroke
Heat Exhaustion – TREATMENT
Stop activity Remove to cool area Remove clothing Replace oral fluids - water or electrolyte fluid, no stimulants If decrease LOC withhold fluid Monitor ABC and LOC, if changes treat as load and go Cardiac monitoring, ETCO2
GOAL TEMP WHEN YOU ARE COOLING SOMEONE
38.8
Heat Stroke
Least common but most deadly Caused by a severe disturbance in the body’s thermoregulation Core temperature more than 40°C (104°F) Altered mental status No sweating
classic heatstroke
Passive heat stroke Usually occurs during heat waves
exertion heatstroke
Typically an illness of young and fit people exercising in hot and humid conditions Generate heat without any means of excreting that heat
Heat Stroke Treatment
Temperature between 37.7 degrees Celsius and 40 degrees Celsius Stop activity and remove from hot environment Remove excess layers of clothing if required If clinically indicated administer oxygen Cool patient by sponging front and back of patient with lukewarm water, allow air conditioning air currents to flow over the patient to promote cooling Stop cooling if temperature drops below 38.8 degrees, or patient starts shivering Apply cardiac monitor Establish vascular access- fluid Transport
Frostbite
an ischemic injury that is classified as deep or superficialOccurs when ice crystals form between the cells of the skin, and then expand as they extract fluid from the cells
Superficial Frostbite
first layer of skin Frequently involve tips of ears, nose and fingers Presents with loss of sensation and feeling of effected area Commonly feels soft to the touch and pale around area Complains of pain on rewarming Capillary leakage produces edematous skin in the area
Deep Frostbite
all layers of skin Usually involves the hands or feet Looks like wax, white, yellow-white, or mottled blue-white Hard, cold, and without sensation Major tissue damage from thawing Partial refreezing of melted water may occur. As thawing occurs, the injured area turns purple, bluish, mottled and becomes excruciatingly painful Gangrene
Frostbite Care
Remove patient from cold source Do not allow patient to use injured limb Remove coverings from area Rewarm area unless danger of refreezing - body heat, warm environment, warm water Do not rub or massage (ice crystals) Watch for hypothermia Fully frozen limb don’t do anything just transport
Hypothermia
Is an imbalance between heat loss and heat production Some common issues leading to the development of hypothermia are: Cold temperatures Fatigue Improper gear for temperature Wetness Dehydration Malnutrition Length of exposure Intensity of weather conditions
Immersion Hypothermia
Is the result of immersion in cool or cold water which results in a loss of body heat. Outcome may be better Mammalian Diving reflex Not dead till you’re warm and dead
Mild Hypothermia
Below 36 degrees Increased metabolic rate Maximum shivering Thermogenesis
Below 34 degrees
Impaired judgment Slurred speech Passive re warming
Moderate Hypothermia
To 30 - 34 degrees Respiratory depression –Slowing down to save energy Myocardial irritability Bradycardia –Slowing down to save energy Atrial fibrillation Osborn waves or j wave Shivering stops at 32.2 degrees Warm IV fluid After drop is defined as the continued lowering of core body temp even after the patient is removed from the cold environment due to a shift of cold blood from the extremities during re-warming
Severe Hypothermia
Below 30 degrees Half the metabolic rate Loss of reflexes Fixed and dilated pupils VFib Call hypothermia Drugs will not work normally
Hypothermia Treatment
History and Assessment Maintain airway Handle with care Remove wet clothing Retain heat and place in warm environment Warmed oxygen if possible Warmed IV fluids If transport over 1 hour rewarm hot packs on pulse sites, not extremities No resp or pulse, cardiac monitor – CPRALS
Pathophysiology of Drowning and Submersion
Breath holding Water enters the mouth and nose A small amount of water is aspirated into the posterior pharynx and perhaps the trachea. Sets off spasms of the laryngeal muscles that seal off and protect the airway Water begins to enter the lungs.
Laryngospasm
Leads to asphyxia and the patient may lose consciousness ‘ “Dry drowning” – cant get air in Only happens in cold water
Drowning and Submersion Management
Resuscitation ABCs –Assist ventilation as soon as possible with BVM and oxygen –If there are weasels administer bronchodilators Trauma considerations —Immersion episode of unknown etiology warrants trauma management Post-resuscitation complications –Adult respiratory distress syndrome (ARDS) or renal failure often occur post-resuscitation –Symptoms may not appear for 24 hours or more post- resuscitation Fresh versus saltwater considerations -No difference in prehospital treatment
