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Home , Frostbite

Environmental : 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

Hypothermia – Core body temperature below 95°F (35°C).

Frostbite – Direct freezing of tissue when 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 -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. Hypothermia Diagnosis -Accurate core temp -Symptom recognition:

>90° Early symptoms Feeling cold, shivering, social withdrawal Moderate Confusion, sleepiness, slurred 82-90° hypothermia 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

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

Treatment Mild: Remove cold, wet clothing. Shelter Allow shivering Avoid massage Passive 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

Frostbite

Localized cold injury produced by freezing of tissue.

Sites typically affected are furthest from core. – Hands, feet, face, nose and

Also from direct contact. – Metal, petroleum products… Frostbite

Sensation at varying skin temperatures:

82° Cooling sensation  68° Pain  50° Numbness

Vasoconstriction

Cold exposure Tissue freezing Cell wall damage

Inflammation F2a, thromboxane Risk Factors

Castellani, John W et al. Prevention of Cold Injuries During Exercise. Medicine & Science in Sports & Exercise. 38(11):2012-2029, November 2006. Frostbite Superficial- Normal skin color, large (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 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 – on dorsum of great – 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 HACE HAPE Acute Mountain High-altitude High- cerebral edema pulmonary edema

-Rapid ascent past 8,000ft -Headache is usually initial symptom of illness -Descent is definitive therapy High Altitude Illness AMS HACE HAPE Acute Mountain High-altitude High-altitude Sickness cerebral edema 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 HACE HAPE Acute Mountain High-altitude High-altitude Sickness cerebral edema pulmonary edema

Lake Louse Questionnaire 1) Headache 2) Additional symptom 3) Total score >3 High Altitude Illness AMS HACE HAPE Acute Mountain High-altitude High-altitude Sickness cerebral edema pulmonary edema

CNS symptoms ataxia, altered consciousness, confusion, drowsiness, stupor and coma Underlying mechanism is unclear. High Altitude Illness AMS HACE HAPE Acute Mountain High-altitude High-altitude Sickness cerebral edema pulmonary edema

MCC of altitude related death. Typically presents 48-96hrs after arrival above 8,000ft AMS 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 pressure Subsequent 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 HACE-Dexamethasone 8mg once, 4mg QID HAPE-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 BID Dexamethasone 4mg PO BID Under scrutiny 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 BID Dexamethasone 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 BID Dexamethasone 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. Thank You

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.