11/8/2017. Notice. Road Map

Transcription

1 Notice All EMS presentations will be recorded (both audio and video) and available for public viewing online. By participating in EMS you consent to audio and video recording and its/their release and or publication. You have been fully informed of your consent and release prior to your participation. Spokane County EMS Thermoregulation Cold Related Injuries Heat Related Injuries Road Map 1

2 Thermoregulation Spokane County EMS Pathophysiology of Thermoregulation Thermoregulatory center located in the posterior hypothalmus regulates body temperature This center receives input from central thermoreceptors in or near the anterior hypothalmus and from peripheral thermoreceptors located in the skin and some mucus membranes. Information from these receptors is transmitted via nerves and ascending pathways to the posterior hypothalmus. The hypothalmus responds with appropriate output to decrease heat loss- by increasing heat production or increasing heat loss by decreasing heat production Pathophysiology of Thermoregulation Thermoregulatory center has a inherent set point of 37 degrees C (98.6 F) Homeostasis body s processes of maintaining supply and demand of the body s needs. As it relates to thermoregulation it does this in two ways: Thermogenesis (heat production) Thermolysis (Release of stored heat and energy) 2

3 Thermoregulatory Mechanisms Thermogenesis Main method of dealing with cold stressors Skin is the body s thermostat. Increases muscle tone and initiates shivering in the short term Increases thyroid levels in the long term Hypothalamus shunts blood to the core. Sweating decreases. Persons physiological & biochemical factors which affect these compensatory mechanism include age, health factors, nutritional status. Thermolysis can occur in five different ways + Thermoregulatory body glands = skin blood flow (vasocontriction or vasodilatation), sweating and shivering Cold Injuries Spokane County EMS 3

4 Hypothermia is defined as: A drop in body temperature below that required for normal metabolism and bodily functions where the amount of heat lost exceeds that which is able to be produced; characterized by a temperature below 95*F (35*C); usually caused by prolonged exposure to cold and/or damp conditions. Body factors Increased thermolysis Out in the environment for an extended period Decreased thermogenesis Shock state Anemia Impaired thermoregulation Head injury Alcohol on board Certain prescription medications Hypothermia Hypothermia Further broken down to primary and secondary hypothermia: Primary results from failure of heat generation in the face of a cold environment i.e. adaptive processes not working well (muscle activity & shivering) physical conditioning, dehydration and lack of caloric intake makes the problem worse Secondary results when a disease state interferes with thermoregulation processes and the bodies ability to maintain its own body temperature primary and secondary can exist concurrently injury to the hypothalamus (thermoregulatory center) underlying illness/disease process that compromises regulatory mechanisms prescription medications that affect a patient s ability to compensate bottom line need to have a high degree of suspicion 4

5 Issues leading to the development Cold temperatures Length of exposure Intensity of weather conditions Improper gear for adverse conditions Wetness of clothes or incontinence Dehydration Malnutrition Risk Factors for Hypothermia Risk Factors for Hypothermia Alcohol / Drug Intoxication Most common cause of heat loss in urban settings Impairs shivering thermogenesis Promotes cutaneous vasodilation Liver disease creates inadequate glycogen stores and subnormal nutritional status. Impairs judgment Risk Factors for Hypothermia Age Extremes Often cannot generate heat effectively Reduced muscle mass and a diminished shivering response Certain medications may interfere with vasoconstriction. 5

6 Other Risk Factors Diabetic Fall Stroke Cardiac Arrest Unconscious Difficulty Breathing Toxin exposure Immune suppressed Infection/Sepsis Pediatric Allergic Reaction Altered LOC AND ALSO Risk Factors for Hypothermia Trauma Hypothermic temperatures are increased for trauma patients due to deadly complications such as: cardiac rhythm changes hypoglycemia coagulopathies (blood clotting problems) hypotension Hypovolemia Trauma patients become hypothermic at a higher temperature than non-trauma patients Degrees of Hypothermia Hypothermia is categorized and further defined by degree :. (no pun intended ) MILD; MODERATE; SEVERE 6

7 PATHOPHYSIOLOGY vs. S/S: MILD Hypothermia ( ) Hypothalamus initiates sympathetic nervous system response causing an increase in BP, pulse and cardiac output. Vasoconstriction-Blood is redirected to muscles where it can be warmed by the initiation of the shivering response. Increase in metabolism. Signs and Symptoms in the field: shivering hyperreflexia tachycardia, hypertension, (increased cardiac output) altered mental status, confusion some may try to be removing their clothes tachypnea PATHOPHYS vs. S/S (Cont): MODERATE- ( F) Body unable to reach/maintain functional temperature, shivering stops; metabolism slows down; decreased O2 demand and CO2 production; cold diuresis; dilated pupils. Signs and Symptoms in the field: sympathetic nerve impairment hypotension, bradycardia atrial fibrillation/flutter & ectopy bradypnea, decreased lung compliance Altered mental status; loss of consciousness Coagulopathy Gag reflex may not be present at <89.9*F. PATHOPHYSIOLOGY vs. S/S (CONT.): SEVERE- (< F) Systems are hypoxic and exhausted; Metabolic & Respiratory acidosis; unresponsive; pulmonary edema; loss of reflexes. Signs and Symptoms in the field: Ventricular fibrillation & asystole increased myocardial contractility severe hypotension decreased/absent respirations unconscious 7

8 ECG CHANGES IN HYPOTHERMIC PATIENTS (CONT.) As the core temperature falls, the cardiac rhythm progresses from: Tachycardia Bradycardia Atrial fib (with a slow ventricular rate) V-fib Asystole V-fib is usually refractory to defibrillation & Medications until a body temperature of 86*F (30*C) or greater is obtained. Easy Identification of the Hypothermic Patient: Look for the umbles : Stumbles Fumbles Mumbles Grumbles Questions to ask yourself on scene: What are they laying/sitting on? (Tile floor/living room carpet/pavement/car) How long have they been there? What type of environment are they in? (Temperature/wind) Are they properly dressed? (For age group/season?) Are they breathing rapidly? Are they wet: DIAPHORETIC? incontinence? Do they have a chronic illness? (COPD, CHF, Diabetes, neuropathy, cancer) Are they on multiple medications? Is there a possibility of head injury? Are they intoxicated (ETOH/illicit drugs)? 8

9 How do we treat it? Passive Rewarming Getting victim out of cold environment Blankets Removing wet clothes Moisture barriers Active rewarming: all the above plus Heat packs Warmed IVs Treatment General Treatment: Prevent further heat loss (blankets) Remove wet/restrictive clothing Remove from environment Convective (forced air) warming is effective in restoring heat to the core although radiant heat (hot packs) may be easier to apply. Good assessment that includes HPI, any pt. meds Warmed O2 (if possible) Glucose check Cardiac monitoring VS take longer to check HR & RR Gentle handling of patient 9

10 Treatment of Hypothermia Breathing patients with a pulse Mild hypothermia cases: 93.2 F Passive rewarming Promote heat generation Moderate hypothermia cases: 86 F to 93.2 F Passive and active external rewarming of the truncal areas cautiously Afterdrop phenomena Severe hypothermia cases: less than 86 F Passive rewarming only Role of IV Fluids in the Hypothermic Patient: Fluid resuscitation can result in substantial core temperature decreases, mandating the use of efficient fluid-warming devices. Fluids are generally infused into the body at or near room temperature Consequentially the patient must give up his/her own heat to warm the infused fluids, thus exacerbating the problem of hypothermia. Crystalloids should be warmed to at least 104*F (40*C) prior to administration. ACLS Hypothermia Algorithm Pulse or breathing absent Start CPR Defibrillate max three times Attempt, confirm, secure airway Ventilate with warmed O2 IV access - Infuse warm saline Core Temperature <30 (86 ) >30 -Continue CPR -Continue CPR -Withhold IV meds -Active rewarming (if within 15 min) -Limit shocks to max of three -Repeat defib as core temp rises -Transport -Give IV Meds space out longer in time 10

11 Other Cold Related Injuries Spokane County EMS Local Cold Injury Most injuries are localized to the extremities or exposed parts. Tips of the ears, nose, upper cheek, and tips of the fingers or toes Local Cold Injury Frostbite effects the epidermis & dermis Environmentally induced freezing of body tissues Ice crystals form within and water is drawn out of the cells into extracellular space. As the ice crystals expand they cause destruction of the cells intracellular electrolyte concentration increases causing further destruction to the cells Sludging of cold, viscous blood further contributes to tissue hypoxia also after thawing cellular level may further compound extent of damage Frostbite is classified according to depth of injury 11

12 Local Cold Injury Superficial frostbite epidermis affected Most common symptoms Altered sensation Skin typically appears white and waxy. Skin is firm to palpation, but the underlying tissues remain soft. Capillary leakage produces edema in the frostbitten area. Superficial frostbite (cont.) Most common symptoms (cont.) Severe tingling, throbbing pain during rewarming Edema accumulation within hours Clear fluid filled vesicles within 3-24 hours Hard, black eschar within a week Local Cold Injury Local Cold Injury Prehospital treatment Differs significantly from that of deep frostbite If the tissues beneath the skin are soft when you press down on the skin surface, the frostbite is probably superficial. Combination of dressing, rest, food, and limiting exposure Get the patient out of the cold. Rewarm the injured part with body heat. Do not rub or massage the frostbitten area. Cover blisters with a dry, sterile dressing. Transport the patient to the hospital. 12

13 Local Cold Injury Deep Frostbite: Disrupted nutritional capillary flow never restored to damaged tissue Affected area remains cold, mottled and blue or gray after rewarming. During first 9-15 days skin forms a black eschar Edema is slow to form Deep blisters with purple blood containing fluid appears within 1-3 weeks Within days a line of demarcation between the eschar and viable skin develops gangrene Local Cold Injury Prehospital treatment: Don t rewarm if chance that extremity could refreeze Rewarm if possible and practical in hot water (104 ) Don t allow patient to walk on extremity No alcohol or tobacco products May need pain control Heat Related Injuries Spokane County EMS 13

14 Heat Illness Increase in core body temperature Due to inadequate thermolysis Inability to get rid of the heat buildup in the body Body adaptation to Heat: Body has the ability to acclimatize to hot environments by decreasing heat production and increasing heat loss efficiency takes days glycogen stores increase allowing for less heat production Volume of sweat that is produced is increased The temperature at which sweating starts is lowered Risk Factors for Heat Illness Risk Factors for Heat Illness Older people are at a particular risk. Do not adjust as well to the heat Perspire less Acclimatize more slowly Feel thirst less readily Decreased mobility More likely to have chronic conditions More apt to be taking medications that disrupt the body s mechanisms for dissipating heat 14

15 Risk Factors for Heat Illness Infants and young children exposed to a hot environment Proportionately higher metabolic heat production Body Temperature that rises faster during dehydration Do not dissipate heat as well Heat Cramps Acute involuntary muscle pains Usually in the lower extremities, the abdomen, or both Occur because of profuse sweating and subsequent sodium losses water follows NaCl (hyponatremia) Svetlana Larina/ShutterStock, Inc. Heat Cramps Treatment Move the patient to a cool environment. If the patient is not nauseated, give one or two glasses of a salt-containing solution or sports drink. 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. 15

16 Heat Exhaustion (Prostration) Clinical syndrome Milder form of heat illnesses Volume depletion and heat stress Symptoms Headache, fatigue, dizziness, nausea, vomiting, and, sometimes, abdominal cramping Skin is pale and clammy. Core temperature mildly elevated (<104 ) Tachycardia Tachypnea + Orthostatic VS Urine Output Sometimes misdiagnosed If untreated may progress to heat stroke Heat Exhaustion Heat Exhaustion Treatment Aimed at removing the patient from exposure to heat and repairing the derangement in fluid and electrolyte balance Move the patient to a cool environment, remove excess clothing. If the patient s temperature is elevated, sponge, spray, or drip the patient with tepid water and fan gently. 16

17 Heat Exhaustion Treatment (continued) Oral hydration with sports drinks If nausea and vomiting are present, start a normal saline IV and draw blood for electrolyte determinations. Cautiously give fluids by mouth. Monitor cardiac rhythm, vital signs, temperature If you cannot determine whether the patient has heat exhaustion or heat stroke, treat for heat stroke. Heat Stroke Least common but most deadly Caused by a severe disturbance in the body s thermoregulation Body s compensating mechanisms fail Two findings Core temperature more than 104 F (40 C) Neurologic dysfunction Other systems are affected organ and tissue damage seems to be more related to duration of elevated temperature (versus the magnitude of the elevation) Heat Stroke Two syndromes Classic Passive heat stroke 80% with sudden onset Usually occurs during heat waves Often the elderly or debilitated or the young Often suffer from chronic illnesses or alcoholism May be taking meds that impair adaptation to heat stress 17

18 Heat Stroke Exertional Typically an illness of young and fit people exercising in hot and humid conditions Generate heat without any means of excreting that heat May be very diaphoretic May be hypoglycemic Heat Stroke The clinical picture of heat stroke Patients will not be able to give a coherent history. Earliest signs are changes in behavior. Irritability, combativeness, and signs the patient is hallucinating Older patients may present with signs resembling those of a suspected stroke. Tremors, seizures, constricted pupils, and decerebrate or decorticate posturing If CNS intact: Cardiac Output Tachycardia progresses bradycardia Tachypnea Apnea Sweating Heat Stroke Fever and conditions that mimic heat stroke History may suggest infectious causes. Fever signals that the body is fighting an infection by inhibiting reproduction of harmful toxins. Drug O/D PCP, Cocaine, Meth 18

19 Heat Stroke Treatment of heat stroke If in doubt treat for heat stroke!! remove the patient from the environment and promote rapid cooling evaporate cooling by spraying tepid water over the patient while transporting Heat Stroke Treatment (continued) Evaluate the ABCs, administer supplemental oxygen, and be prepared to intubate. Cool as rapidly as possible by the most expeditious means available body temperature to 102. Start an IV line, give normal saline carefully may lead to pulmonary edema Check the blood glucose level. Monitor cardiac rhythm. Be prepared to treat seizures. Treatment (continued) Check the blood glucose level. Monitor cardiac rhythm. Be prepared to treat seizures. Heat Stroke 19

20 Post Test 1. The thermal regulation center is located in the? a. Heart b. Kidneys c. Lungs d. Hypothalamus Post Test 2. Name four ways that our body loses heat? a) b) c) d) Post Test 3. Signs and symptoms of severe hypothermia include: a. Severe shivering b. Tachycardia c. Pulseless d. Tachypnea 20

21 Post Test 4. The body s normal reaction to heat exhaustion is to start to shiver to compensate. a. True b. False Post Test 5. Classic heat stroke usually occurs in all of the following populations except: a. Geriatrics b. Pediatrics c. Immune suppressed d. Healthy adult Secret Question Winners Were you the first to answer tonight s Secret Question? Get your prize! If so, please healthtraining@inhs.org with your name and sponsoring agency address. We would like to feature you and your agency in next months presentation, so please also send in anything you would like to share about your organization including upcoming events, recent calls, employment opportunities, etc. 21

22 Rosters & Certificates All EMS materials including roster, handouts and certificates are available on the following INHS Health Training website: LiveatNite-Courses/ Please fax or documents to or Thank Thank You You 22