Sports Medicine: Just the Facts

236 SECTION 3 • MEDICAL PROBLEMS IN THE ATHLETE

particular patient is located. Immediate treatment

increases the likelihood of the body’s return to normal

thermoregulation and prevents progression to heat-

stroke.

• Field treatment should involve cessation of activity,
  removal to a shaded, cool environment, fluid replace-
  ment beverages, and fanning after spraying the patient
  with a cool mist. Heat cramps can be treated with pas-
  sive stretching of the affected muscles.


• In case of altered mental status, seizures, or a core
  temperature greater than 104°F, heatstroke should be
  presumed, and the patient should be evacuated for
  definitive emergency care. If the patient responds to
  field treatment they should avoid exertion for at least
  24–48 h to avoid a transient, but increased risk of
  recurrent heat illness.


• Heatstroke treatment involves the nine steps shown in
  Table 39-4 (Moran and Gaffan, 2001). Concerns that
  ice water immersion would increase seizures or trig-
  ger shivering thermogenesis have been allayed by
  recent studies (level of evidence B, nonrandomized
  clinical trials) (Costrini, 1990; Gaffin, Gardner, and
  Flinn, 2000; Weiner and Khogali, 1980).

FIVE KEYS TO PREVENTION

• Acclimatizationto high heat and humidity for 10–14
  days prior to competition is ideal. The first 4 to 5 days
  are when two key physiologic changes occur: changes
  in sweat composition and an increase in the ability of
  the body to rapidly dissipate heat.


• Clothingshould be light colored, lightweight, and
  offer sun-protection.


• Medicationsthat impair heat loss should be stopped or
  changed, e.g., change antihistamines to nasal steroids
  to treat allergic rhinitis and stop ephedra compounds.


• Activity planning or reductionshould be based on the
  WGBT scale: <65 low risk for heat illness, 65–75

moderate risk, 75–85 high risk individuals should not

exercise, 85–90 unacclimated athletes should stop,

>90 all activities should stop (Armstrong et al, 1996).

• Prehydration and hydration per ACSMrecommenda-
  tions. These can be summarized for patients as fol-
  lows: drink 16 oz of water or sports beverage 2 h
  before exercise—if no urination, repeat 15 min before
  exercise. During exercise drink 20–40 oz every hour
  divided in 5–10 oz amounts every 20 min. After exer-
  cise, replace each pound of weight lost with 32 oz of
  fluid (Armstrong et al, 1996).

ALTITUDE ILLNESS

DEFINITIONS AND CLINICAL SYNDROMES

• Rapid ascent past 8000 ft leads to the onset of the
  physiologic effects of decreased oxygen concentration
  at altitude. These effects are most pronounced for
  those attempting exercise at altitude. Several clinical
  syndromes exist:


• High altitude headache(HAH) is the first symptom of
  altitude exposure. It may or may not progress to acute
  mountain sickness.


• Acute mountain sickness(AMS) is a syndrome that
  includes HAH and at least one of four symptoms:
  nausea/vomiting, fatigue/lassitude, dizziness, or
  insomnia.


• High altitude cerebral edema(HACE) is the clinical
  progression of AMS so that severe CNS symptoms
  develop, such as ataxia, altered consciousness, confu-
  sion, drowsiness, stupor, or coma.


• High altitude pulmonary edema(HAPE) is the most
  common cause of altitude related death. It is charac-
  terized by classic signs of pulmonary edema: wet
  cough, dyspnea at rest, weakness, and orthopnea.

EPIDEMIOLOGY

• Altitude illness is most common in the unacclima-
  tized, regardless of fitness level, who ascend rapidly
  past 8000 ft. The severity is linked to the rate of
  ascent, altitude attained, sleeping altitude, length of
  altitude exposure, level of exertion, and an individ-
  ual’s inherent physiologic susceptibility that remains
  static despite reexposure.

PATHOPHYSIOLOGY

•A rapid rate of ascent, an inappropriately slowed

hypoxic ventilatory response to ambient hypoxia and

hypercarbia, fluid retention, and vasogenic edema are

TABLE 39-4 Treatment of Heatstroke

Immediate cooling. If available, ice water immersion is best. If not,
fanning after misting the patient should be undertaken. Cool until
rectal temp reaches 39°C (102.2°F).
Avoid antipyretics. The hypothalamic set point is normal! They can
aggravate hepatic or renal injury.
Avoid alcohol baths. Vasodilated skin can lead to systemic absorption.
Monitor core temperature until it is < 38 °C (100.5°F).
Consider diazepam (5 mg) or lorazepam (2 mg) to control shivering and
as prophylaxis against seizures.
Monitor renal function closely. Early dialysis is indicated.
Correct persistentelectrolyte abnormalities.
Check coagulation profile at admission and serially until 72 h have passed.
Use fresh frozen plasma (FFP) and/or platelets as needed.
Rehydrate vigorously–monitor for fluid overload and hyponatremia.