Environmental Injuries: The Winter Athlete. Thomas Moran, MD Primary Care Sports Medicine Fellow University of Chicago - NorthShore

Transcription

1 Environmental Injuries: The Winter Athlete Thomas Moran, MD Primary Care Sports Medicine Fellow University of Chicago - NorthShore

2 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

3 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

4 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.

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6 Hypothermia Definition: Core temperature less than 95 Develops when total body heat loss exceeds physiologic heat production.

7 Diagnosis -Accurate core temp Hypothermia -Symptom recognition: >90 Early symptoms Feeling cold, shivering, social withdrawal Moderate hypothermia Confusion, sleepiness, slurred speech *Irritable cardiac tissue <82 Severe Eventual loss of consciousness, loss of reflexes *Arrhythmias common

8 J-wave

9 Predisposing Risk Factors Castellani, John W et al. Prevention of Cold Injuries During Exercise. Medicine & Science in Sports & Exercise. 38(11): , November 2006.

10 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 ) *Afterdrop Phenomenon

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12 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

13 Frostbite Sensation at varying skin temperatures: 82 Cooling sensation 68 Pain 50 Numbness Vasoconstriction Hypoxia Cold exposure Tissue freezing Cell wall damage Inflammation Prostaglandin F2a, thromboxane

14 Risk Factors Castellani, John W et al. Prevention of Cold Injuries During Exercise. Medicine & Science in Sports & Exercise. 38(11): , November 2006.

15 Frostbite Superficial- Normal skin color, large blisters (serous or white), intact pinprick, skin indents with pressure. Deep- Nonblanching cyanosis, dark blisters (sanguineous), Skin wooden to touch.

16 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 H 2 O ( ) Debride clear blisters, Leave blood filled

17 Frostbite blister presentation

18 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

19 Protected area Activity modification Wait and see 10 days after initial eval Case

20 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: , 2003

21 Cold injury Prevention NOAA.gov

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23 Altitude affects Altitude environment Cold Low Humidity UV radiation Decreased air pressure Linear correlation between barometric pressure and available oxygen mmhg Sea level -520 mmhg 10, mmhg 18,000 ft University of Colorado

24 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

25 High Altitude Illness AMS 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

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

27 High Altitude Illness AMS 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.

28 High Altitude Illness AMS 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 8,000ft 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.

29 Treatment Acute Mountain Sickness - assent and rest. -Descend/recompression if no improvement -Low flow oxygen -Carbonic anhydrase inhibitor Acetazolamide ( mg BID) HACE & HAPE -Immediate descent, Oxygen -Specific Adjuvant medications HACE-Dexamethasone 8mg once, 4mg QID HAPE-Nifedipine 30mg BID

30 Prevention High Altitude Illness 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 mg BID Dexamethasone 4mg PO BID Under scrutiny Ibuprofen 600mg TID, Sildenafil, Inspiratory muscle training and resistance apparatus.

31 Acetazolamide & HAI

32 Prevention High Altitude Illness 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 mg BID Dexamethasone 4mg PO BID Under scrutiny Ibuprofen 600mg TID, Sildenafil, Inspiratory muscle training and resistance apparatus.

33 Ibuprofen as prophylaxis?

34 Prevention Begin exertion below 8,000ft High Altitude Illness 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 mg BID Dexamethasone 4mg PO BID Proposed prevention meds: -Ibuprofen 600mg TID, -Sildenafil,

35 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):

36 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.

37 Thank You Bartsch P, Swenson ER. Acute high-altitude illnesses. N Engl J Med Oct 24;369(17): Castellani J, Young A, Ducharme M et al. Prevention of Cold Injuries during Exercise. Medicine and Science in Sports and Exercise. 2006; 06: 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):