What is the appropriate management of aluminum phosphide (phosphine) poisoning?

Management of Aluminum Phosphide (Sulphos) Poisoning

All aluminum phosphide exposures require immediate ICU-level care, as ingestion of as little as 150-500 mg can be fatal, and there is no specific antidote—management relies entirely on aggressive supportive measures and prevention of phosphine gas absorption. 1

Immediate Safety and Decontamination

Healthcare Worker Protection

• Use full personal protective equipment including full-face gas masks and butyl rubber gloves before initiating patient care, as phosphine gas is highly toxic and secondary exposure has caused severe illness requiring ICU admission in healthcare workers. 1
• Ensure treatment areas are well-ventilated; healthcare workers have required atropine, pralidoxime, and intubation after exposure to phosphine vapor in poorly ventilated spaces. 1

Gastrointestinal Decontamination

• Perform gastric lavage with diluted potassium permanganate solution immediately upon presentation. 2, 3
• Administer coconut oil orally to prevent further absorption of aluminum phosphide—case reports suggest rapid administration may improve survival even after lethal ingestions. 2, 3
• Activated charcoal can be considered, although its ability to adsorb phosphine gas is uncertain. 1

Cardiovascular Support

Hemodynamic Management

• Profound circulatory collapse is the major lethal consequence, secondary to direct myocardial toxicity, fluid loss, and adrenal damage. 4
• Initiate aggressive vasopressor support with continuous hemodynamic monitoring. 3, 5
• Administer intravenous magnesium sulfate as specific therapy—this is the only agent with evidence suggesting potential benefit beyond supportive care. 3, 5

Arrhythmia Management

• For life-threatening ventricular arrhythmias, administer calcium gluconate (100-200 mg/kg/dose) via slow infusion with continuous ECG monitoring. 1
• Lidocaine and magnesium sulfate have been used successfully for ventricular arrhythmias. 6
• Avoid succinylcholine or mivacurium for intubation if cholinesterase inhibition is suspected. 1

Respiratory Management

• Early endotracheal intubation is critical as patients rapidly progress to respiratory failure and pulmonary edema (which may be cardiogenic or non-cardiogenic). 4, 6
• Consider CPAP ventilation for patients with adequate consciousness and without contraindications. 1

Metabolic and Renal Support

Acidosis Management

• Administer sodium bicarbonate (1-2 mEq/kg IV push) for severe metabolic acidosis, which is frequent and contributes to mortality. 1, 2, 4
• Give oral sodium bicarbonate as well. 2, 3
• Never administer sodium bicarbonate and calcium through the same IV line. 1

Renal Failure Management

• Monitor for acute kidney injury, which is frequent. 4, 6
• Initiate continuous renal replacement therapy (CRRT) or hemodialysis for severe metabolic acidosis and acute kidney injury. 6
• Watch for and treat rhabdomyolysis with adequate hydration and urine alkalinization if myoglobinuria develops. 1
• Monitor serum creatinine kinase and potassium to detect rhabdomyolysis. 1

Management of Aluminum Toxicity

Serum Aluminum Monitoring

• Measure serum aluminum levels if aluminum toxicity is suspected. 1

Deferoxamine (DFO) Administration—Critical Thresholds

• For serum aluminum levels 60-200 μg/L: Administer DFO at 5 mg/kg with careful monitoring and use high-flux dialysis membranes for effective clearance of aluminum-DFO complexes. 7, 1
• For serum aluminum levels >200 μg/L: DO NOT administer DFO due to high risk of precipitating acute aluminum neurotoxicity; instead, perform intensive high-flux hemodialysis daily for 4-6 weeks until levels decrease. 7, 1
• If DFO is administered, avoid intravenous iron to limit formation of feroxamine. 1
• Warning: DFO therapy can precipitate fatal mucormycosis with 91% mortality in dialysis patients; use reduced dosing (5 mg/kg) and expanded intervals between treatments to minimize risk. 1

Advanced Life Support

Extracorporeal Support

• Consider veno-arterial ECMO for refractory cardiogenic shock—successful recovery from multiorgan failure has been documented with ECMO support for up to 16 days. 6
• Prompt referral to a tertiary care center with ECMO and CRRT capability is recommended for all suspected or documented aluminum phosphide poisoning. 6

Monitoring and Supportive Care

• Close observation for at least 48-72 hours is mandatory even in apparently stable patients. 8
• Monitor for multiorgan toxicity involving heart, kidneys, lungs, and liver. 4, 6
• Watch for disseminated intravascular coagulation and hepatic necrosis. 4
• Contact poison control (1-800-222-1222 in the United States) for expert guidance on specific case management. 8

Critical Pitfalls to Avoid

• Never delay ICU admission—patients rapidly progress from nonspecific symptoms (epigastric pain, vomiting, diarrhea, dizziness, dyspnea) to multisystem organ failure, cardiovascular collapse, and death. 6
• Never use aluminum hydroxide as a phosphate binder for more than 1-2 days to avoid cumulative aluminum toxicity. 1
• Avoid physical restraints without adequate sedation as this worsens outcomes. 1
• Despite intensive care, mortality remains 30-77% as there is no antidote to phosphine or metal phosphide poisoning. 4, 6