Acute Kidney Injury
| Acute Rhabdomyolysis
- Heat stroke is defined by cerebral dysfunction in the context of body core temperature >40°C.
- Non-exertional: Elderly and the very young are at highest risk often chronic illnesses and medications. Hot weather and high heat and humidity over time. Bedridden or living in poorly ventilated or no conditioned conditions. May be on Antiparkinson treatment, diuretics, or anticholinergic therapy or obese (harder to loose heat).
- Exertional heat stroke: young people in good health who are exercising in a
hot, humid environment, often with clothing or equipment that restricts cooling. Athletes, labourers, Military. It is rapid in onset with altered mental state, ataxia, coma, and nuchal rigidity or posturing may also occur. Profuse sweating is a typical finding on examination. Drugs may play a role - cocaine, alcohol withdrawal, LSD, amphetamines.
- Anxiety, confusion, bizarre behaviour, loss of coordination
- Hallucinations, agitation, seizures
- Sweating may or may not be present
- Hypotension, tachycardia and coma in severe cases
- FBC : raised WCC if infection
- U&E: AKI, hypokalaemia and low phosphate is seen
- Raised CK (usually in exertional heat stroke)
- Raised AST is poor prognostic indicator
- VBG: Respiratory alkalosis +/- lactic acidosis (exertional)
- Renal failure or rhabdomyolysis (most commonly in exertional heat stroke)
- Acute respiratory distress syndrome
- Myocardial injury and circulatory collapse
- Hepatocellular injury
- Intestinal ischaemia and infarction
- Pancreatic injury
- Disseminated intravascular coagulation
- Malignant hyperthermia
- Neuroleptic malignant syndrome
- Drug-induced hyperthermia
- Infections: Especially meningitis, encephalitis, and sepsis
- Endocrinopathies: thyroid storm and phaeochromocytoma
- CNS lesions: Hypothalamic bleeding, acute hydrocephalus
- Rapid cooling is the main therapeutic goal for the treatment of heatstroke
- Immersion in ice water is effective but poorly tolerated for prolonged periods
- Tepid water spray (40°C) and a forced air stream from a fan, has proved successful and is an easy therapy to apply. Ice packs and massage may be used.
- Target is a core temperature of 39°C or less is considered safe
- Dantrolene is not indicated for the treatment of heatstroke.