What is the best course of treatment for a patient presenting with peripheral eosinophilia, hypothermia, and severe metabolic acidosis?

Management of Peripheral Eosinophilia with Hypothermia and Severe Metabolic Acidosis

This clinical triad suggests a life-threatening emergency requiring immediate simultaneous correction of hypothermia and metabolic acidosis while urgently investigating the underlying cause of eosinophilia, as the combination carries significant mortality risk from cardiovascular collapse, coagulopathy, and end-organ damage.

Immediate Resuscitation (First 30 Minutes)

Airway and Breathing

• Intubate and hyperventilate with 100% oxygen at 2-3 times normal minute volume to correct acidosis and facilitate active core rewarming 1
• Deliver warm, humidified oxygen through the ventilator circuit to prevent further heat loss 1

Circulation and Monitoring

• Establish two large-bore IV lines and consider arterial line, central venous access, and urinary catheter 1
• Obtain immediate labs: arterial blood gas, lactate, potassium, creatinine kinase, glucose, complete blood count with differential, renal/hepatic function, coagulation studies 1
• Continuous cardiac monitoring for arrhythmias (bradycardia and ventricular arrhythmias are common with hypothermia) 1

Active Rewarming Protocol

• Infuse 2000-3000 mL of warmed (4°C) 0.9% saline IV 1
• Apply surface warming: forced-air warmers, warm blankets, heat packs to axillae and groin 1
• Target core temperature >36°C before stopping rewarming 1
• Monitor temperature every 5 minutes until >36°C 1

Acidosis Correction

• If pH <7.2, administer sodium bicarbonate IV (50-100 mEq initially, then 50 mEq every 5-10 minutes as guided by serial blood gases) 1, 2
• The FDA label indicates 2-5 mEq/kg over 4-8 hours for less urgent acidosis, but cardiac arrest protocols allow more aggressive dosing 2
• Hyperventilation to normocapnia is the primary treatment; bicarbonate is adjunctive 1

Electrolyte Management

• Treat hyperkalemia if present with dextrose 50% 50 mL + 50 units insulin IV, plus calcium chloride 0.1 mmol/kg IV 1
• Hypothermia commonly causes hyperkalemia; this will improve with rewarming 1

Urgent Diagnostic Workup (Concurrent with Resuscitation)

Eosinophilia Investigation

• Obtain detailed travel history, dietary exposures (raw fish, undercooked meat), and medication history 3
• Stool microscopy for ova and parasites (three samples) 1
• Serology for Strongyloides, Schistosoma, Toxocara, and other helminths based on exposure history 1
• Assess for end-organ damage: chest X-ray, ECG, echocardiogram if cardiac symptoms, neurological examination 3

Rule Out Critical Differential Diagnoses

• Exclude malignant hyperthermia if recent anesthetic exposure with volatile agents or succinylcholine, though hypothermia (not hyperthermia) makes this unlikely 1
• Consider drug-induced causes: hydroxyurea can cause severe metabolic acidosis with gastrointestinal symptoms 4
• Evaluate for sepsis with broad-spectrum antibiotics if infection suspected 5

Empiric Antiparasitic Treatment

For returning travelers with eosinophilia and severe systemic illness, initiate empiric treatment immediately after obtaining specimens 3:

• Ivermectin 200 mcg/kg PO daily for 2 days (for Strongyloides, which can cause hyperinfection syndrome) 3
• Albendazole 400 mg PO twice daily for 14 days (broad-spectrum coverage) 1
• Add praziquantel 40 mg/kg PO in divided doses if schistosomiasis suspected based on freshwater exposure in endemic areas 1

Critical Caveat for Corticosteroids

• Do NOT administer corticosteroids until Strongyloides is excluded or treated, as steroids can precipitate fatal hyperinfection syndrome 1, 3
• If eosinophilic meningitis is suspected (headache, neurological signs), corticosteroids are indicated but only AFTER ivermectin treatment 1

Ongoing Management (First 24 Hours)

Monitoring Requirements

• Continuous monitoring in ICU for minimum 24 hours 1
• Serial blood gases every 1-2 hours until pH >7.35 and temperature >36°C 1
• Monitor for recrudescence of hypothermia or acidosis 1
• Urine output >2 mL/kg/hour to prevent myoglobin-induced acute kidney injury if rhabdomyolysis present 1

Arrhythmia Management

• Amiodarone 300 mg IV (3 mg/kg) for ventricular arrhythmias 1
• Beta-blockers (esmolol, metoprolol) for persistent tachycardia 1
• Defibrillation may be attempted if VF/VT present, though efficacy is reduced below 30°C 1

Fluid Management

• Maintain euvolemia with crystalloids (lactated Ringer's or 0.9% saline) 1
• Furosemide 0.5-1 mg/kg or mannitol 1 g/kg if oliguria develops 1

Common Pitfalls to Avoid

• Do not delay rewarming while investigating the cause of eosinophilia—hypothermia with severe acidosis is immediately life-threatening 1, 6
• Do not assume eosinophilia is incidental—it may indicate helminth infection causing the systemic decompensation 3
• Do not give corticosteroids empirically without first treating or excluding Strongyloides 1, 3
• Do not stop rewarming at 34-35°C—target is ≥36°C to restore normal physiology 1
• Do not over-correct acidosis rapidly to pH >7.4 in the first 24 hours, as this can cause rebound alkalosis when ventilation normalizes 2, 7
• Do not assume normal CT angiogram excludes serious pathology if free fluid or other concerning findings are present 5

Prognosis and Escalation

• Mortality is high when hypothermia, severe acidosis, and coagulopathy coexist (the "lethal triad") 1, 5
• If ≥4 organ failures persist after 1 week of adequate treatment, consider goals-of-care discussion 5
• Consult infectious disease/tropical medicine specialist urgently for eosinophilia management 1, 3
• Consult nephrology if dialysis needed for refractory hyperkalemia or acidosis 1