Environmental Injuries:The Winter Athlete
Thomas Moran, MD
Primary Care Sports Medicine Fellow
University of Chicago - NorthShore
Introduction
Chicago Marathon >41,000 runners– 2006 (36° start,48° high with slight rain)– 2007 (88° high, 80% humidity)
American Birkebeiner >10,000 skiers– 2011 (-6° start)– Last decade, 6 starts under 10°
Leadville 100 >300 runners– Start 10,400 ft, peak >12,500 ft
Cold Injury
Hypothermia – Core body temperature below 95°F (35°C).
Frostbite – Direct freezing of tissue when skin temperature drops below 32°F (0°C)
“Man in the cold is not necessarily a cold man.”-David Bass 1958
Physiologic response to Cold
Peripheral Vasoconstriction-First response to cold exposure.-Once Skin temp below 95°F.-Insulating effect.
Increased metabolic heat production- Shivering, peaks with skin temp 68° F and core
of 95°.-Increases basal metabolic rate up to 5x
baseline.
Hypothermia
Definition: Core temperature less than 95°
Develops when total body heat loss exceeds physiologic heat production.
HypothermiaDiagnosis
-Accurate core temp
-Symptom recognition:
>90° Early symptoms Feeling cold, shivering, social withdrawal
82-90°Moderate hypothermia
Confusion, sleepiness, slurred speech…*Irritable cardiac tissue
<82° Severe Eventual loss of consciousness, loss of reflexes…*Arrhythmias common
J-wave
Predisposing Risk Factors
Castellani, John W et al. Prevention of Cold Injuries During Exercise. Medicine & Science in Sports & Exercise. 38(11):2012-2029, November 2006.
Hypothermia
TreatmentMild:
Remove cold, wet clothing. ShelterAllow shiveringAvoid massagePassive external (warm blankets, PO warm liquid)
Moderate to Severe:Active external (hot water bottles, heating pads, etc)Active core (D5NS at 104°-108°)
*Afterdrop Phenomenon
Temp Features Treatment/Rewarming
95° Max shivering Passive external
91° Ataxia, apathy Passive external
90° Stupor, shivering ceases, Arrhythmias Active external
<82° Decreased Vfib threshold Active core
Frostbite
Localized cold injury produced by freezing of tissue.
Sites typically affected are furthest from core.
– Hands, feet, face, nose and ears
Also from direct contact.
– Metal, petroleum products…
Frostbite
Cold exposure
Vasoconstriction
Tissue freezing
Inflammation
Hypoxia
Cell wall damage
Prostaglandin F2a, thromboxane
Sensation at varying skin temperatures:
82° Cooling sensation 68° Pain 50° Numbness
Risk Factors
Castellani, John W et al. Prevention of Cold Injuries During Exercise. Medicine & Science in Sports & Exercise. 38(11):2012-2029, November 2006.
FrostbiteSuperficial- Normal skin color, large blisters (serous or
white), intact pinprick, skin indents with pressure.Deep- Nonblanching cyanosis, dark blisters (sanguineous),
Skin “wooden to touch.”
Frostbite
Prognosis: • Vascular studies• Watchful waiting. ultimate viability not determined
until 22- 45days.
Treatment: • Do not rewarm if risk of refreezing! • Do not massage!• Rapid submersion….rewarm affected parts in H2O
(104°-108°)• Debride clear blisters, Leave blood filled
Frostbite blister presentation
Case
• 19yo college XC runner following up for tibia stress reaction
• Week previous, had increased mileage
– Went for 13mi run in bitter cold
• Next day
– Blood blister on dorsum of great toe
– Attributed to runners toe
• 1 week later…
Case
• Protected area• Activity modification• Wait and see• 10 days after initial eval…
Cold Injury - Prevention
*Avoid cold wet exposure*
Choice clothing “3L”
Loose
Layered
Lightweight
Wind/waterproof outer layer
Avoid emollients on skin
Thorleifsson, A., and H. C. Wulf. Emollients and the response of facial skin to a cold environment. Br. J. Dermatol. 148: 1149-52, 2003
Cold injury – Prevention
NOAA.gov
Altitude affects
• Altitude environment – Cold– Low Humidity– UV radiation– Decreased air pressure
• Linear correlation between barometric pressure and available oxygen.-760 mmHg Sea level-520 mmHg 10,000-380 mmHg 18,000 ft
University of Colorado
High Altitude Illness
AMS
Acute Mountain Sickness
HACE
High-altitude cerebral edema
HAPE
High-altitude pulmonary edema
-Rapid ascent past 8,000ft-Headache is usually initial symptom of
illness-Descent is definitive therapy
High Altitude IllnessAMS
Acute Mountain Sickness
HACE
High-altitude cerebral edema
HAPE
High-altitude pulmonary edema
-Most common illness by travelers to altitude-Symptoms 6-12 hrs after ascent to >8,000ft.
Headache with:nausea, fatigue, dizziness or insomnia
-No validated physiologic markers
High Altitude Illness
AMS
Acute Mountain Sickness
HACE
High-altitude cerebral edema
HAPE
High-altitude pulmonary edema
Lake Louse Questionnaire 1) Headache2) Additional symptom3) Total score >3
High Altitude IllnessAMS
Acute Mountain Sickness
HACE
High-altitude cerebral edema
HAPE
High-altitude pulmonary edema
CNS symptoms ataxia, altered consciousness, confusion, drowsiness, stupor and coma
Underlying mechanism is unclear.
High Altitude IllnessAMS
Acute Mountain Sickness
HACE
High-altitude cerebral edema
HAPE
High-altitude pulmonary edema
MCC of altitude related death. Typically presents 48-96hrs after arrival above 8,000ftAMS with classic signs of pulmonary edema (wet cough, dyspnea
at rest, weakness and orthopnea)Etiology for disease:
Hypoxia leads to exaggerated hypoxic pulmonary vasoconstriction.
Increased PA pressureSubsequent transudative leak.
Treatment
Acute Mountain Sickness- assent and rest.-Descend/recompression if no improvement-Low flow oxygen-Carbonic anhydrase inhibitor
Acetazolamide (125-250mg BID)HACE & HAPE
-Immediate descent, Oxygen-Specific Adjuvant medications
HACE-Dexamethasone 8mg once, 4mg QIDHAPE-Nifedipine 30mg BID
High Altitude Illness
Prevention
Begin exertion below 8,000ft
2-3 nights 8-10,000ft then ascend
Beyond 10,000ft, ascend 1500 ft before another nights rest
Avoid alcohol and opiates
Avoid dehydration and hypothermia
*Acetazolamide 125-250mg BIDDexamethasone 4mg PO BID
Under scrutiny Ibuprofen 600mg TID,Sildenafil, Inspiratory muscle training and resistance apparatus.
Acetazolamide & HAI
High Altitude Illness
Prevention
Begin exertion below 8,000ft
2-3 nights 8-10,000ft then ascend
Beyond 10,000ft, ascend 1500 ft before another nights rest
Avoid alcohol and opiates
Avoid dehydration and hypothermia
Acetazolamide 125-250mg BIDDexamethasone 4mg PO BID
Under scrutiny Ibuprofen 600mg TID,Sildenafil, Inspiratory muscle training and resistance apparatus.
Ibuprofen as prophylaxis?
High Altitude Illness
Prevention
Begin exertion below 8,000ft
2-3 nights 8-10,000ft then ascend
Beyond 10,000ft, ascend 1500 ft before another nights rest
Avoid alcohol and opiates
Avoid dehydration and hypothermia
Acetazolamide 125-250mg BIDDexamethasone 4mg PO BID
Proposed prevention meds:-Ibuprofen 600mg TID,-Sildenafil,
Role of Nitric Oxide
-Observed increases in NO during acclimatization.
-PDE-5 as treatment and prophylaxis
-Adjuvant treatment in cases with HAPE
-Prophylaxis
SE profile outweighs
protective benefit.
Bates MG et al. Sildenafil citrate for the prevention of high altitude hypoxic pulmonary hypertension. High Alt Med Biol.2011; 12 (3): 207-14.
Altitude
• Allow adequate acclimatization above 8000ft.
– Ascend less than 1500 ft per day.
• Identify altitude related illness
• HAPE and HACE are emergencies!
• Definitive treatment is descent.
• Prophylaxis includes slow assent and if necessary Carbonic Anhydrase inhibitors.
Bartsch P, Swenson ER. Acute high-altitude illnesses. N Engl J Med. 2013 Oct 24;369(17):1666–7
Castellani J, Young A, Ducharme M et al. Prevention of Cold Injuries during Exercise. Medicine and Science in Sports and Exercise. 2006; 06: 2012-29.
Grieve A, Davis P, Dhillon S, Richards P, Hillebrandt D, Imray C. A clinical review of the management of frostbite. J R Army Med Corps. 2011: 157(1):73-8.
Derby R, DeWeber K. The Athlete and High Altitude. Current Sports Medicine Reports. 2010: 9 (2): 79-85.
O’Conner F, et al. ACSM Sports medicine: A Comprehensive Review. 2010.
Thank You
Top Related