Do stroke patients, particularly those in the acute phase, typically experience hypothermia?

Do Stroke Patients Have Low Body Temperature?

No, stroke patients typically do not have low body temperature—in fact, hyperthermia (elevated temperature) is a frequent complication occurring in up to 50% of acute ischemic stroke patients, and is strongly associated with worse outcomes and increased mortality. 1

Temperature Patterns in Acute Stroke

Hyperthermia is Common, Not Hypothermia

• Hyperthermia occurs in up to 50% of acute ischemic stroke patients and represents a major clinical concern rather than hypothermia 1
• Elevated body temperature is directly associated with stroke severity and poor functional outcomes 2, 3
• Each 1°C increase in admission body temperature independently predicts a 30% relative increase in long-term mortality risk (95% CI: 4% to 57%) 2
• Hyperthermia is associated with the highest mortality rates: 51.78% in hemorrhagic stroke and 56.66% in ischemic stroke, compared to 0% mortality in hypothermic patients 4

Mechanisms of Temperature-Related Injury

Hyperthermia worsens stroke outcomes through multiple pathways 1:

• Increased production of excitotoxins and oxygen radicals 1
• Destabilization of cellular membranes 1
• Abnormal electrical depolarizations 1
• Increased oxygen demand that may aggravate cardiac or pulmonary insufficiency 1
• Induction of mental status changes in patients with brain disease 1

Clinical Temperature Management Recommendations

For Patients with Hyperthermia (>38°C)

The American Heart Association/American Stroke Association recommends administering antipyretic medication to lower temperature in stroke patients with hyperthermia (Class I, Level C recommendation) 1

• Acetaminophen is modestly successful in achieving normothermia, though patients with temperatures >38°C may be relatively unresponsive 1, 5
• Higher doses (6000 mg daily) may have more significant temperature-lowering effects than lower doses (3900 mg daily) 1
• Treatment reduces mean body temperature by approximately 0.26°C within 24 hours (95% CI: 0.18°C–0.31°C) 1

Important Caveat on Evidence Quality

The European Stroke Organisation cannot make a recommendation for treating hyperthermia specifically to improve functional outcome and/or survival (quality of evidence: ⊕⊕/?) 1

This apparent contradiction with AHA/ASA guidelines reflects different outcome measures:

• ESO focused on functional outcome and survival as primary endpoints 1
• AHA/ASA focused on temperature reduction and patient comfort 1
• ESO acknowledges this does not preclude giving antipyretics to relieve discomfort associated with hyperthermia 1

For Normothermic Patients

Routine prevention of hyperthermia with antipyretics is not recommended as a means to improve functional outcome and/or survival in normothermic stroke patients (quality of evidence: ⊕⊕⊕/↓?) 1

• A large trial (PAIS-1) with prophylactic paracetamol showed no benefit in preventing poor outcomes (adjusted OR 1.20,95% CI 0.96-1.50) 6

Induced Hypothermia is Not Recommended

Therapeutic hypothermia is not recommended for routine use in acute ischemic stroke to improve functional outcome and/or survival (quality of evidence: Very low/⊕) 1

• Analysis of 252 patients showed no significant difference in favorable functional outcome (RR: 0.92,95% CI: 0.63–1.33) 1
• No significant difference in mortality (RR: 1.20,95% CI: 0.65–2.22) 1
• Despite promising experimental data, clinical evidence remains insufficient 3, 7

Practical Clinical Approach

Temperature Monitoring Strategy

• Monitor body temperature continuously in acute stroke patients, particularly in the first 24-72 hours 1, 6
• The duration of fever is directly related to prognosis and is an independent prognostic factor in patients surviving the first 72 hours 6
• Maintain normothermia at 36-37°C rather than attempting hypothermia 6

When Fever is Detected (≥38°C)

1. Identify and treat infectious sources 6, 8
2. Administer antipyretic medications (acetaminophen as first-line agent) 6, 5
3. If fever persists despite antipyretics, consider automated temperature control devices with servo-regulation 6

Critical Pitfall to Avoid

Do not assume stroke patients are hypothermic—the opposite is true, and failure to recognize and treat hyperthermia may worsen outcomes significantly 2, 9, 4