-IBIS-1.5.0-
tx
nervous system
heatstroke
diagnoses

definition and etiology

definition: A grave reaction to high temperatures following inadequate response or overload of the heat-regulating mechanism. Also called "sunstroke", "hyperpyrexia", and "thermic fever".

etiology: Heatstroke is most commonly seen in elderly patients already afflicted with chronic disease. Other susceptible individuals include patients with diabetes; alcoholics; users of anticholinergic drugs; military recruits during basic training; and patients with diseases of the skin causing impaired sweating, such as scleroderma. The mechanism of heatstroke is not well understood.

signs and symptoms

signs and symptoms:
Onset is typically abrupt: Prodromal symptoms include vertigo, fatigue, abdominal distress, confusion and headache.
• Absence of perspiration (usually).
• Skin is hot, dry and flushed.
• Pulse increases: up to 160-180/min.
• Temperature: 105-106°F rectally; core temperatures have been recorded reaching 112-113° F.
• Respirations are rapid and weak.
• Patient feels as if he is "burning up".
• Circulatory collapse and shock are grave indicators.

lab findings:
• AST increased usually 20 times normal by 36 hours.
• ALT increased 10 times normal.
• LDH increased by third day to 5 times normal.
• Serum potassium may be increased or decreased.
• Signs of kidney damage: mild proteinuria to acute oliguria.
• DIC is seen in severe cases.
• Abnormal EKG may appear.

course and prognosis

Heatstroke is a serious medical emergency and patients may die within a few hours of being discovered, or from complications such as acute renal failure. If the hyperpyrexia lasted for hours and the patient survived, brain damage may have occurred. Patients may also die weeks after the episode, often of myocardial infarction, heart failure or kidney failure. Prognosis improves with early treatment.

differential diagnosis

• heat exhaustion
• malaria
• meningitis
• encephalitis


footnotes