Introduction:

This report describes the case of a 38-year-old man who suffered severe heatstroke following a strenuous hike on a hot, humid day. The case highlights the importance of early diagnosis, aggressive temperature management, and supportive care in improving outcomes for heatstroke patients.

Case Presentation:

A 38-year-old man with no significant past medical history presented after collapsing at the end of a hike in late July. He reported dizziness and eventually became unresponsive. Upon arrival by emergency medical services, he was experiencing a seizure and was in a coma (Glasgow Coma Scale score of 6). His core body temperature measured 40.8°C.

Investigations:

• Initial CT Scan: A head CT scan was performed to rule out bleeding or stroke in the brain. The results were normal.
• Lumbar Puncture: A lumbar puncture was performed to rule out meningitis or encephalitis as potential causes of his altered mental state. Cerebrospinal fluid analysis showed normal results.
• Laboratory Tests:
  • Liver Function Tests: Liver function tests revealed abnormalities, indicating potential liver damage from heatstroke.
  • Kidney Function Tests: Initial kidney function tests showed elevated creatinine and blood urea nitrogen (BUN) levels, suggesting early kidney dysfunction.
  • Muscle Damage Markers: Elevated levels of myoglobin and creatine kinase (CK) indicated muscle damage (rhabdomyolysis), a common complication of heatstroke.
  • Cytokine Levels: Blood tests measured elevated levels of cytokines (IL-2R, IL-6, IL-8, TNF alpha). These inflammatory markers supported the diagnosis of heatstroke.

Treatment Course:

• Temperature Control: Initial attempts to lower his body temperature using conventional methods such as cooling blankets and medications like non-steroidal anti-inflammatory drugs (NSAIDs) and opioids were unsuccessful.
• Given the severity of his condition and persistent high temperature, an intravascular cooling system (CoolGard®) was implemented. This system uses a catheter placed in a major vein to circulate cooled saline and effectively reduce core body temperature. The target temperature was set at 37°C and later adjusted to 37.5°C. This intervention successfully lowered and maintained his core body temperature within a safe range.
• Kidney Protection: To prevent kidney failure due to rhabdomyolysis, aggressive diuresis was initiated using high doses of furosemide and fluids, which helped to flush out muscle breakdown products from the kidneys.
• Antibiotics: Based on suspicion of aspiration pneumonia and sinusitis identified on the initial CT scan, a course of antibiotics (tazobactam/piperacillin and clindamycin) was administered.

Outcomes:

With aggressive temperature management and supportive care, the patient's condition gradually improved. His body temperature remained stable, kidney function recovered to normal levels, and no lasting neurological deficits were observed. He was successfully extubated on day 8 and transferred to a regular neurological ward on day 12. At the time of discharge from the intensive care unit after 12 days, all laboratory parameters had returned to normal.

Discussion:

This case demonstrates the effectiveness of intravascular cooling in managing severe heatstroke. Early diagnosis and prompt intervention are crucial for preventing complications and improving patient outcomes. The elevated cytokine levels in this case further support the diagnosis of heatstroke and highlight the body's inflammatory response to this condition.