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