KIN 188 – Prevention and Care KIN 188 – Prevention and Care of Athletic Injuriesof Athletic Injuries

KIN 188 – Prevention and Care KIN 188 – Prevention and Care of Athletic Injuriesof Athletic Injuries

Environmental ConditionsEnvironmental ConditionsEnvironmental ConditionsEnvironmental Conditions

Heat Regulation

• Thermoregulatory system responsible for maintaining a consistent core temperature of 98.6°F

• As part of the regulatory process, the body must dissipate a majority of the heat produced by normal body functions

Internal Heat Regulation

• In moderate or cool weather, dissipation occurs through passive heat loss (radiation, conduction, convection)

• In hot, humid weather, passive heat loss is inadequate

• During intense exercise, internal heat production increases significantly

• ↑ heat production + ↓ heat loss = DANGER

Evaporation

• When air temperature > skin temperature, body relies primarily on sweating for heat loss

• Sweat production alone does not result in heat loss from the skin– Evaporation of sweat results in heat loss

• Total sweat evaporated from skin depends on– Skin surface exposed to the environment– Temperature and relative humidity of ambient air– Convective air currents around the body

Evaporation

• Relative humidity– Ratio of water in the ambient air to the total quantity of

moisture that can be carried

• When humidity is high, evaporation will be slow -minimal water is accepted into the air

• Sweating continues but evaporation is slight - could result in substantial fluid loss - up to 2.5 L/ hr (6 lbs.)

• Excessive fluid loss without replacement → dehydration

Measuring Heat-Stress Index• Requires measurement of ambient air

temperature, humidity and solar radiant energy

• Wet-Bulb-Globe Temperature Index (WBGT) – Ambient temperature (Ta)– Wet bulb temperature (Tw) – Black globe temperature (Tg) – Outdoor use

• WBGT = (0.1 x Ta) + (0.7 x Tw) + (0.2 x Tg)

– Indoor use• WBGT = (0.3 x Ta) + (0.7 x Tw)

Measuring Heat-Stress Index

WBGT Flag Color

Level of Risk Comments

65oF Green Low Risk low but still exists on the basis of risk factors

65-73oF Yellow Moderate Risk level increases as event progresses through the day

73-82oF Red High Everyone should be aware of injury potential; individuals at risk should not compete

>82oF Black Extreme or hazardous

Consider rescheduling or delaying the event until safer conditions prevail; if the event must take place, be on high alert

Measuring Heat-Stress Index

• Sling psychrometer– Tool utilized to identify Ta, Tw and Tg

• Reference materials – www.nata.org– NATA position statement on exertional heat

illness (2002)

• Inter-Association Task Force on Exertional Heat Illness (2003)– Developed universal guidelines for reducing risk of

heat illness

Heat Illness

• Heat rash/prickly heat (miliaria rubra)

• Heat syncope (fainting)

• Heat cramps

• Heat exhaustion

• Heat stroke

• Hyponatremia

Heat Rash

• Inflamed, itchy skin eruption from blockage of active sweat glands

• Most common in humid environments and in areas covered by clothing

• Typical treatment involves cooling and drying involved skin area and treating itching symptoms with topicals

• Typically resolves in 1-2 days with rest

Heat Syncope

• Typically occurs toward end of activity for non-acclimated individuals

• When activity stops, most blood volume is in extremities to drive activity

• Too little venous return available to heart to meet blood supply needs of brain

• As a result, individual faints (syncopal episode)

• Treat with removal from environment and elevation of legs to encourage return of blood to core

Heat Cramps• Exercise-associated muscle (heat) cramps

– Involuntary muscle spasms caused by excessive water and electrolyte loss

• Signs and symptoms– Transient cramps– Fatigue– Normal pulse, respiration and body temperature– Skin cool and moist

• Management– Ice and stretch– Replenish fluids– Rest

Heat Exhaustion

• Ineffective circulatory adjustments compounded by a depletion of extracellular fluid due to excessive sweating

• Signs and symptoms– Thirst– Headache– Dizziness/lightheadedness– Mild anxiety– Profuse sweating– Cool, clammy, ashen/pale skin– Normal or slightly elevated body temperature (<103°F)– Rapid and weak pulse (tachycardia)

Heat Exhaustion

• Management– Remove from environment and rest in a cool area– Remove equipment and clothing– Execute rapid cooling of body via sponge/towel with

cool water, ice towels, ice bags, fans/cool mist machine

– Replacement of fluids – critical element• Best if cool to assist reduction of body temperature

• Best if also contain electrolytes

• May need IV administration

– Refer to physician (EMS?)

Heat Stroke• Failure of body’s thermoregulatory system

– Hypothalamus unable to regulate body temperature– Increased temperature → increased metabolic rate →

increased heat production – vicious cycle established

• Signs and symptoms– Initial presentation with confusion/disorientation, profuse

sweating– Symptom progression evidenced by cessation of sweating– Skin becomes hot/dry/red– Typically become unconscious – convulsions/seizures

possible– Significantly elevated core body temperature (105+°F)

• Shallow breathing, ↓ BP, rapid/weak pulse

Heat Stroke• Management

– Activate EMS – life threatening condition– Remove from environment, remove

clothing/equipment– Rapid cooling of the body – critical element

• Best method is immersion in cold water• Also can use ice towels, ice bags, etc.

– Ultimate restoration of fluid and electrolyte balance• Typically done via IV administration

– If not treated correctly, death is imminent• Mortality directly related to magnitude and duration of

elevated body temperature

Hyponatremia

• Low blood sodium associated with exercising for long periods of time– Usually because individual drinks too much water and

loses too many electrolytes via sweat– Dilutes sodium content of blood – can be fatal

• Signs and symptoms include– Headache, nausea, cramping, swelling in extremities

• Treatment is activation of EMS– Typically require IV administration of electrolytes

and/or diuretics to restore fluid/electrolyte balance

Factors that Modify Heat Tolerance

• Acclimatization– Body's ability to tolerate heat improves with repeated exposure

• Key is gradual progression of exercise intensity during heat– Best done over 10–14 days (considerations for away events)– Schedule activities during cooler times of day– Implement frequent breaks for fluid intake

• Fluid rehydration– Maintain plasma volume to promote optimal circulation and

sweating– Thirst is not an accurate indicator of water needs– Drink before, during and after practice– Loss of body weight > 2% is problematic– Monitor color and volume of urine– For every pound of water lost, 24 oz. of fluid should be ingested

• Use of weight charts before/after activity

Factors that Modify Heat Tolerance

• Electrolyte replacement– Electrolytes

• Sodium, chloride, magnesium and potassium• Regulate fluid balance, nerve conduction and muscle

contractions – Sweat contains high levels of sodium and chloride– Replaced with normal diet – may need to augment– Use of electrolyte drinks – optimal concentration of

electrolytes– Avoid diuretics – alcohol, caffeine, meds

• Clothing– Light-colored, lightweight, porous clothing – Least amount of clothing appropriate to the sport– Awareness of problems that can be caused by equipment

(catchers, goalies, etc.)

Factors that Modify Heat Tolerance

• Age– Children

• lower sweating capacity & higher core temperature during exposure to heat

• sweat composition differs—do not benefit from electrolyte beverages

• require longer acclimatization time

– Middle-age and older adults• less tolerant to heat and exercise

• delayed onset of sweating

• dehydration recovery difficult

Cold Related Conditions

• Primary heat-promoting mechanisms when body exposed to cold temperatures– Cutaneous vasoconstriction to prevent blood from

shunting to skin – Increased metabolic heat production by shivering or

increased physical activity– Release of hormone thyroxine to increase metabolic rate

• Body heat lost through– Respiration, radiation, conduction, convection and

evaporation

Cold Related Conditions

• Prevention– Check weather conditions (temperature, wind chill)– Implement “layered principle” of clothing– Use of ski cap, face mask, and neck warmer/scarf to

cover typically exposed areas during activity– Avoid dehydration – drink cool liquids– Move periodically – increases metabolic rate– Stay dry – use waterproof outer gear, socks to keep

moisture away from body surface

Frostbite• Freezing of soft tissue• Cold urticaria (allergy) and Raynaud’s syndrome - ↑

susceptibility to frostbite

1st Degree (superficial)

Skin is soft to touch and appears initially red, then white, and is usually painless. The condition is typically noticed by others first.

2nd Degree(involves subcutaneous tissues)

Skin is firm to touch but tissue beneath is soft and appears initially red and swollen. Diffuse numbness may be preceded by an itchy or prickly sensation. White or waxy skin color may appear later

3rd Degree(deep tissues)

Skin is hard to touch and totally numb, and appears blotchy white to yellow-gray or blue-gray.

Frostbite

• Management– Remove from cold environment ASAP– Superficial

• Careful, rapid rewarming• Warm water immersion ideal (102°F–108°F)• Re-warmed skin may present with blisters• Sterile, dry dressings applied

– Deep • Transport to hospital for controlled warming and continued

care• Re-warmed skin typically has hemorrhagic blisters• Gangrene may develop over next couple of weeks

Hypothermia

• Systemic body cooling

• Exposed surfaces lose heat through radiation– Greater risk with longer exposure to environment

• Wind chill factor escalates heat loss from body– Up to 75% of heat loss is through head

• Core temperature needs to maintain 94° F for normal biochemical processes

Hypothermia(ºC) (ºF) Signs and Symptoms

35.5–37.2 96–99 Intense involuntary shivering

32.8–35 91–95 Persistent violent shivering, difficulty with speech if conscious

30–32.2 86–90 Shivering decreases and is replaced by muscular rigidity with jerky erratic movements. Thinking is clouded, and amnesia may be present*

27.2–29.4 81–85 Loss of awareness of surroundings, irrational thinking, drifting into a stuporous state. Rigidity continues, and heart and respiration rates slow. Cardiac arrhythmias may be present

25.6–26.7 78–80 Unconsciousness. Reflexes cease to function, and heartbeat is erratic

<25.6 <78 Cardiac and respiratory centers fail. Edema and hemorrhage occur in lungs, leading to death

*Note: Rough handling can trigger cardiac arrest at or below 32ºC (90ºF).

Hypothermia

• Management– Remove from cold environment ASAP– Activate EMS

• If severe, re-warming must be done in controlled environment to adequately address metabolic/cardiovascular devlopments

– Remove wet clothing– Use external warming devices

• Hot water bottles, heating pads, hot tubs

– Hot, decaffeinated drinks if swallowing possible

Altitude Disorders• Altitude sickness

– Disorder related to hypoxia at high altitudes– Associated with rapid ascent (<24 hrs) to altitudes >

6500 ft – Can be 6–36 hours between altitude arrival and

symptom onset – Signs and symptoms include

• Headache, dizziness, fatigue, nausea/vomiting, suppressed appetite, dyspnea, decreased urine output

– Prevention via acclimatization and physical conditioning in new environment

– Management of symptoms includes ↓ altitude, rest, frequent small meals

Air Pollution and Exercise• Carbon monoxide

– Interferes with the ability of hemoglobin to transport oxygen to the cellular level

• Sulfur oxides – from burning coal/petroleum products– Potent bronchoconstrictor in asthmatics

• Nitrogen oxides – from high temperature combustion (airports, fire fighting, etc.)– Potential for reduced pulmonary function

• Ozone – vehicle and factory emissions– Can exacerbate existing respiratory condition

• Primary particulates – dust, soot, smoke– Can impair pulmonary function when inhaled into the lungs

Lightning Safety• Lightning injuries

– Most common injuries are burns from high temperature of lightning strike and resulting concussive forces that can propel objects through the air, causing blunt trauma

– Mechanisms include direct strike, contact injury, side flash (splash), ground current (step voltage), and blunt trauma

– Lichtenburg figure• Characteristic skin pattern after lightning strike – resembles a

feather pattern on the skin– Critical factor determining mortality is duration of apnea

rather than cardiac asystole– Management

• If in respiratory and cardiac arrest - activate EMS, initiate CPR, rescue breathing and/or defibrillation

Lightning Safety

• “Flash to bang theory”– If lightning is seen, count time from “flash” of lightning to

“bang” of thunder

– Divide time in seconds by 5 = distance in miles of lightning strike

• If 6 miles (30 seconds) away, increase monitoring of conditions and be prepared to immediately seek shelter

• If 3 miles (15 seconds) away, immediately seek shelter

– If shelter not immediately accessible, avoid other risk areas• Water (pool), metal objects (bleachers, light poles), tall

structures (trees, light poles)

• Seek low ground in open space, make self small (crouch in ball vs. laying flat on ground – surface area)