From the Guidelines
Hyperthermia is associated with poor outcomes in patients with acute ischemic stroke, including increased morbidity, mortality, and decreased quality of life. The effects of hyperthermia can be mediated by increased production of excitotoxins and oxygen radicals, destabilization of cellular membranes, and abnormal electrical depolarizations 1. Hyperthermia also increases oxygen demand and may aggravate cardiac or pulmonary insufficiency, and it may also induce mental changes in patients with brain disease.
Key Points
- Hyperthermia is a frequent complication in up to 50% of patients with acute ischemic stroke 1
- Hyperthermia is associated with poor neurological outcome, possibly secondary to increased metabolic demands, enhanced release of neurotransmitters, and increased free radical production 1
- Maintenance of normothermia or lowering of an acutely elevated body temperature has been hypothesized to improve the prognosis of patients with stroke 1
- Measures to achieve normothermia or prevent hyperthermia include both pharmacological and mechanical interventions, such as the use of antipyretics like paracetamol or acetaminophen 1
Treatment
The use of antipyretics like paracetamol or acetaminophen may be considered to relieve the symptom of discomfort associated with hyperthermia, although the evidence for its effectiveness in improving functional outcome and/or survival is limited 1. The European Stroke Organisation (ESO) guidelines do not recommend routine prevention of hyperthermia with antipyretics as a means to improve functional outcome and/or survival in patients with acute ischemic stroke and normothermia 1. However, the American Heart Association/American Stroke Association (AHA/ASA) guidelines recommend that antipyretic medication should be administered to lower temperature in patients with stroke and hyperthermia 1.
Outcome
The outcome of hyperthermia in patients with acute ischemic stroke is generally poor, with increased morbidity, mortality, and decreased quality of life 1. A large, 2500-patient, randomized, double-blind, placebo-controlled trial evaluating whether early treatment with acetaminophen improved functional outcome by reducing body temperature and fever prevention found no statistical difference between groups 1. However, a meta-analysis of the relationship of hyperthermia and stroke mortality in patients with acute stroke demonstrated a 2-fold increase in short-term mortality in patients with hyperthermia within the first 24 hours of hospitalization 1.
From the Research
Effects of Hyperthermia
The effects of hyperthermia can be severe and potentially life-threatening. Some of the key effects include:
- Cellular damage and organ failure when core temperature reaches 104°F (40°C) or higher 2, 3, 4
- Central nervous system symptoms, such as delirium and coma, which can occur in heatstroke 2, 3, 5
- Cardiovascular hypoperfusion and multiorgan damage 3, 5
- Rhabdomyolysis, hepatic failure, arrhythmias, and disseminated intravascular coagulation 3, 5
- Death, if left untreated or if treatment is delayed 2, 3, 5
Risk Factors
Certain individuals are at greater risk of developing heat-related illnesses, including:
- Athletes, outdoor laborers, and military personnel 3, 4
- People with medical conditions, such as diabetes and skin disease with reduced sweating 4
- Older adults and young children 4
- People taking certain medications, such as beta-blockers, anticholinergics, and diuretics 4
- People who are obese or have excessive alcohol consumption 4
Treatment and Prevention
Treatment for hyperthermia typically involves rapid cooling, fluid replacement, and physiologic support 2, 3, 6, 5. Prevention measures include: