What is the treatment approach for aluminum phosphide poisoning?

Aluminum Phosphide Poisoning: Treatment Approach

Critical Initial Recognition

Aluminum phosphide poisoning is a medical emergency with 70-100% mortality even with ingestion of as little as 150-500 mg, requiring immediate ICU-level care and aggressive supportive management as there is no specific antidote. 1, 2, 3

Upon ingestion, aluminum phosphide releases highly toxic phosphine gas when exposed to gastric moisture, causing rapid multi-organ failure including refractory shock, severe metabolic acidosis, cardiac arrhythmias, acute renal failure, and hepatobiliary impairment. 2, 3

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Immediate Management Algorithm

1. Airway and Respiratory Support

• Intubate early if respiratory failure develops or consciousness deteriorates. 3, 4
• Consider CPAP ventilation for patients with adequate consciousness and no contraindications. 1
• Ensure proper ventilation of treatment areas as phosphine gas can affect healthcare providers. 1

2. Cardiovascular Stabilization

Refractory hypotension and cardiogenic shock are the hallmarks of toxicity:

• Initiate aggressive fluid resuscitation with crystalloid solutions immediately. 1, 4
• Start vasopressor support (norepinephrine) early for persistent hypotension despite fluids. 3, 4
• Administer calcium gluconate (100-200 mg/kg/dose) via slow IV infusion with continuous ECG monitoring for life-threatening arrhythmias. 1
• Do not administer sodium bicarbonate and calcium through the same IV line. 1

3. Metabolic Acidosis Management

• Administer sodium bicarbonate (1-2 mEq/kg IV push) for severe metabolic acidosis. 1
• Monitor arterial blood gases continuously as severe acidosis develops rapidly. 3, 4

4. Cardiac Arrhythmia Management

• Magnesium sulfate is recommended as a membrane stabilizer to reduce cardiac arrhythmias. 2, 5, 6
• Lidocaine can be used for ventricular arrhythmias. 5
• Maintain continuous cardiac monitoring throughout treatment. 1

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Advanced Supportive Therapies

Adjunctive Cardioprotective Agents

Emerging evidence supports the use of:

• Trimetazidine (cardioprotective agent) 2
• N-Acetyl cysteine (antioxidant support) 2, 4
• Thiamine, Vitamin C, and hydrocortisone (membrane stabilization and metabolic support) 2

Renal Support

• Monitor for rhabdomyolysis by checking serum creatinine kinase and potassium levels. 1
• Treat rhabdomyolysis with adequate hydration and urine alkalinization if myoglobinuria develops. 1
• Initiate continuous renal replacement therapy (CRRT) or hemodialysis for acute kidney injury and persistent metabolic acidosis. 5

Extracorporeal Support

• Veno-arterial ECMO should be considered for refractory cardiogenic shock in centers with capability. 5
• Prompt referral to a tertiary care center with ECMO and CRRT capability is recommended for severe cases. 5

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Special Considerations for Aluminum Toxicity

When to Measure Serum Aluminum

• Measure serum aluminum levels if aluminum toxicity is suspected, particularly in dialysis patients or prolonged exposures. 1

Deferoxamine (DFO) Use - Critical Dosing Algorithm

For serum aluminum levels 60-200 μg/L:

• Administer DFO at 5 mg/kg with careful monitoring. 1
• Use high-flux dialysis membranes for more effective clearance of aluminum-DFO complexes. 1
• Do not administer intravenous iron to limit formation of feroxamine if DFO is given. 1

For serum aluminum levels >200 μg/L:

• Do NOT administer DFO due to high risk of precipitating acute aluminum neurotoxicity. 7, 1
• Instead, perform intensive dialysis with high-flux membranes (daily hemodialysis for 4-6 weeks until levels decrease). 7
• Only after levels fall below 200 μg/L should low-dose DFO testing (5 mg/kg) be considered. 7

DFO-Related Complications to Avoid

• Fatal mucormycosis can occur with DFO therapy (91% mortality in dialysis patients). 7
• Use reduced dosing (5 mg/kg) and expanded intervals between treatments to minimize risk. 1
• Feroxamine (DFO-iron complex) requires 3-4 dialysis treatments for clearance and promotes fungal growth. 7

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Critical Pitfalls to Avoid

• Never use physical restraints without adequate sedation as this worsens outcomes. 1
• Avoid aluminum hydroxide as a phosphate binder for more than 1-2 days to prevent cumulative aluminum toxicity. 1
• Do not delay ICU admission - all exposures require intensive monitoring regardless of initial presentation. 1, 3
• Hyperbaric oxygen therapy has no role in aluminum phosphide poisoning and should not be considered. 8

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Monitoring Requirements

• Continuous cardiac monitoring with ECG for arrhythmias 1, 3
• Serial arterial blood gases for metabolic acidosis 3, 4
• Liver function tests (AST, ALT) for hepatotoxicity 3
• Renal function (creatinine, BUN) and electrolytes 3
• Creatinine kinase for rhabdomyolysis 1
• Cardiac troponin for myocardial injury 6