How should acute lung injury from aluminium phosphide poisoning be initially managed in a patient with suspected exposure?

Aluminum Phosphide Poisoning: Initial Management of Acute Lung Injury

Immediately secure the airway with early endotracheal intubation for life-threatening respiratory distress, while ensuring all healthcare personnel wear full personal protective equipment (gas mask and butyl rubber gloves) to prevent secondary phosphine gas exposure. 1, 2

Immediate Airway and Respiratory Management

Personal Protective Equipment (Critical First Step)

• All personnel must wear gas masks and butyl rubber gloves before patient contact—ordinary surgical masks and latex gloves provide no protection against phosphine gas vapor 1
• Phosphine gas released from aluminum phosphide is highly toxic and can cause severe secondary poisoning of healthcare workers, including cases requiring atropine, pralidoxime, and intubation for 24 hours 1, 2, 3
• Ensure treatment areas are well-ventilated; phosphine gas off-gassing has caused healthcare worker illness when patients were treated in poorly ventilated spaces 1

Decontamination Protocol

• Remove all contaminated clothing immediately outside the hospital to prevent vapor generation inside the facility 1
• Perform copious water irrigation of exposed skin surfaces 1
• Never allow gastric lavage without full PPE—gastric contents contain organophosphate compounds that have caused severe secondary poisoning requiring intensive care 3

Intubation Strategy

• Perform early endotracheal intubation for any signs of respiratory distress, altered mental status, or severe metabolic acidosis 2, 3
• Avoid succinylcholine and mivacurium for intubation—these neuromuscular blockers are metabolized by cholinesterase and are contraindicated in phosphide poisoning 2, 3
• Use alternative induction agents such as rocuronium or vecuronium 3

Mechanical Ventilation Parameters

• Consider CPAP ventilation only for conscious, cooperative patients without contraindications (full stomach, bowel paralysis, thoracic/abdominal trauma) 1, 2
• Use low tidal volume ventilation (≤6 mL/kg) with moderate PEEP to prevent ventilator-induced lung injury 1
• Target normoventilation with PaCO2 5.0-5.5 kPa—avoid hyperventilation as it worsens tissue perfusion and increases mortality 1

Supportive Respiratory Care

Oxygenation

• Administer 100% oxygen immediately via high-flow mask or endotracheal tube to all suspected cases while awaiting confirmation 1, 2
• Continue high-flow oxygen until metabolic acidosis resolves and respiratory symptoms improve 1

Monitoring for Complications

• Watch for acute respiratory distress syndrome (ARDS) development—a common cause of mortality in aluminum phosphide poisoning 4, 5
• Monitor for delayed muscle weakness that can occur up to 4 days after exposure, requiring prolonged ventilatory support 1, 3
• Assess for rhabdomyolysis by monitoring creatine kinase and potassium levels—myonecrosis from calcium overload can cause respiratory muscle weakness 1, 2, 3

Critical Pitfalls to Avoid

• Never delay intubation in deteriorating patients—aluminum phosphide causes rapid progression to multiorgan failure and cardiovascular collapse 6, 7
• Never treat patients without proper PPE—secondary exposure has caused severe illness requiring ICU admission in healthcare workers 1, 3
• Never use hyperventilation strategies—this worsens tissue hypoxia and increases mortality 1
• Never perform gastric lavage without full protective equipment—organophosphate-containing gastric contents have caused severe secondary poisoning 3

Advanced Respiratory Support Considerations

ECMO as Bridge Therapy

• For refractory respiratory failure with severe metabolic acidosis (pH <7.1) and cardiogenic shock not responding to conventional treatment within 6-12 hours, consider veno-arterial ECMO 4, 8, 7
• ECMO has demonstrated survival benefit in aluminum phosphide poisoning with reversible myocardial dysfunction and ARDS when initiated early 4, 8
• Expect ECMO support duration of 3-16 days for myocardial recovery 4, 8, 7
• Be aware of significant complication rates including dysrhythmias, cannulation site bleeding, and thrombocytopenia requiring surgical exploration in some cases 4
• Prompt referral to a tertiary center with ECMO capability is recommended for all severe cases 7

Sedation Without Mechanical Ventilation

• If attempting to avoid intubation in less severe cases, use benzodiazepines as first-line agents for agitation, titrated to specific endpoints rather than continuous deep sedation 9
• Avoid opioids—they cause respiratory depression and are inadequately metabolized due to hepatic failure 9
• Never use continuous sedative infusions in non-ventilated patients—this significantly increases risk of respiratory failure requiring intubation 9
• Maintain continuous pulse oximetry and frequent respiratory rate assessment 9