What is the initial management step for a patient with hypothermia and altered mental status?

Activate Rewarming Immediately

This patient requires immediate activation of rewarming protocols for severe hypothermia (30.0°C/86.0°F), making option A the correct answer. 1, 2

Clinical Presentation Analysis

This patient presents with:

• Severe hypothermia with core temperature of 30.0°C (86.0°F), which falls into the severe category (<32°C) 1, 2
• Altered mental status, consistent with hypothermic encephalopathy 3
• Bradycardia (pulse 60), which is expected with hypothermia 3
• The ECG findings (though not fully described) likely show hypothermia-related changes rather than acute coronary syndrome requiring catheterization 4

Why Rewarming is the Priority

The American Heart Association and American College of Cardiology classify this as severe hypothermia requiring immediate active rewarming interventions. 1, 2 At this temperature:

• Cardiac arrhythmias become increasingly likely and the patient requires gentle handling to avoid triggering ventricular fibrillation 1
• Metabolic derangements worsen progressively below 32°C 3
• Mortality risk increases significantly, particularly below 30°C 4

Specific Rewarming Protocol for This Patient

Level 1 Interventions (Immediate):

• Remove any wet clothing immediately 2
• Move to warm environment and cover with at least two warm blankets 1, 2
• Insulate from cold surfaces and cover head/neck 1

Level 2 Interventions (Concurrent):

• Apply forced-air warming blankets (e.g., Bair Hugger) 1, 2
• Administer warmed intravenous fluids 1, 2
• Provide humidified, warmed oxygen 1, 2
• Monitor core temperature every 5 minutes 5

Level 3 Interventions (Consider if inadequate response):

• Active internal rewarming may be necessary given the severity (<32°C) 1, 2
• Options include peritoneal lavage with warmed fluids, extracorporeal rewarming, or endovascular warming catheters 4, 6, 7
• The choice depends on hemodynamic stability and available resources 4

Why Other Options Are Incorrect

Option B (Cath Lab): While the ECG may show changes, these are likely hypothermia-related (Osborn J waves, prolonged intervals) rather than acute MI requiring emergent catheterization. Hypothermia must be corrected first before interpreting cardiac findings. 3

Option C (Magnesium): Not indicated as first-line treatment for hypothermia. While electrolyte abnormalities can occur, rewarming is the priority. 3

Option D (Sodium Bicarbonate): While the patient is on amitriptyline (a tricyclic antidepressant), and altered mental status could suggest overdose, the profound hypothermia (30°C) is the immediate life threat. The hypothermia itself explains the presentation, and sodium bicarbonate for TCA toxicity would only be indicated if there were specific ECG findings of QRS widening >100ms from TCA toxicity, not from hypothermia alone. 3

Critical Rewarming Targets and Monitoring

• Target minimum core temperature of 36°C before considering the patient stable 1, 2
• Cease rewarming at 37°C as higher temperatures are associated with poor outcomes 1, 2
• Monitor continuously for rewarming complications including arrhythmias, coagulopathy, and hypotension 1, 8
• Handle the patient gently throughout to avoid triggering ventricular fibrillation 1

Prognosis

Survival rates for severe hypothermia with stable hemodynamics approach 100% with appropriate rewarming, but drop significantly if cardiac arrest occurs (13% survival) 4. This emphasizes the critical importance of immediate, aggressive rewarming before cardiovascular collapse occurs.