What are the next steps in managing an elderly female patient with hyperthermia, tachycardia, tachypnea, hypertension, and altered mental status, who was found down with no available medical history?

Management of Severe Hyperthermia with Altered Mental Status

Immediately initiate aggressive cooling measures and activate emergency protocols, as this patient presents with life-threatening heatstroke requiring rapid temperature reduction to prevent multi-organ failure and death.

Immediate Actions (First 5 Minutes)

Activate emergency response and begin simultaneous cooling interventions, as survival from heatstroke directly correlates with speed of temperature reduction 1.

• Remove all clothing and move patient to cooler environment if not already done 1
• Initiate whole-body (neck-down) cold water immersion for 15 minutes or until neurological symptoms resolve, as this is the most effective cooling method 1
• If immersion unavailable, apply ice packs to axillae, groin, and neck with wet cold sheets and fans 1
• Administer 2000-3000 mL of chilled (4°C) 0.9% saline IV 1
• Target core temperature of 39°C (102.2°F), then stop active cooling to prevent overshoot 1

Critical Monitoring and Diagnostic Workup

Establish comprehensive monitoring immediately as this patient requires ICU-level care for at least 24 hours 2.

• Establish wide-bore IV access with at least two large-bore cannulas 1
• Insert urinary catheter and target urine output >2 mL/kg/hr 1
• Obtain stat labs: potassium, creatine kinase, arterial blood gas, myoglobin, glucose, renal function, hepatic function, coagulation studies 1
• Continuous cardiac monitoring for arrhythmias given tachycardia of 155 bpm 1
• Consider arterial line and central venous access for hemodynamic monitoring 1

Management of Specific Complications

Cardiovascular Instability

• For persistent tachycardia: Consider beta-blockers (propranolol/metoprolol/esmolol) after ruling out hypovolemia 1
• For arrhythmias: Amiodarone 300 mg IV (3 mg/kg) 1
• Hypertension (165/110) may improve with cooling and sedation; avoid aggressive antihypertensive therapy initially as BP may drop with rehydration 1

Metabolic Derangements

• Monitor for hyperkalemia given muscle breakdown risk; treat with dextrose 50% 50 mL with 50 units insulin and calcium chloride 0.1 mmol/kg IV if present 1
• For metabolic acidosis: Hyperventilate if intubated; give sodium bicarbonate IV if pH <7.2 1
• Prevent acute kidney injury: Maintain urine output with furosemide 0.5-1 mg/kg or mannitol 1 g/kg plus aggressive crystalloid hydration 1

Rhabdomyolysis Prevention

• Monitor CK and myoglobin levels closely 1, 2
• Forced alkaline diuresis may be needed if rhabdomyolysis develops 3
• Check for compartment syndrome in all extremities 1

Critical Differential Consideration

While this presentation is most consistent with environmental heatstroke, consider malignant hyperthermia if there is any recent anesthetic exposure 2.

• Malignant hyperthermia would require immediate dantrolene 2 mg/kg IV, repeated until stabilization (up to 10 mg/kg or more) 1, 2
• However, without anesthetic trigger exposure (volatile anesthetics or succinylcholine), environmental heatstroke is the diagnosis 1, 2
• Dantrolene is not indicated for environmental heatstroke and should only be used if MH is suspected 2

Common Pitfalls to Avoid

• Do not delay cooling while obtaining history - temperature of 106.7°F is immediately life-threatening and requires action within minutes 1
• Do not use antipyretics (acetaminophen, NSAIDs) as they are ineffective for non-hypothalamic hyperthermia 1
• Do not over-cool - stop active cooling at 38.5°C to prevent hypothermia 1
• Do not give oral fluids given altered mental status and aspiration risk 1
• Do not assume single-organ involvement - heatstroke causes multi-organ dysfunction including coagulopathy, hepatic failure, and neurological damage 1, 2

Disposition

Transfer to ICU immediately for continuous monitoring for minimum 24 hours, as delayed complications including DIC, renal failure, and neurological sequelae can develop 1, 2.