What is the recommended management of acute glyphosate poisoning?

Management of Acute Glyphosate Poisoning

There is no specific antidote for glyphosate poisoning; aggressive supportive care with early airway management, hemodynamic support, and close monitoring for at least 48-72 hours is the cornerstone of treatment. 1

Immediate Actions and Personal Safety

Healthcare Worker Protection

• Use appropriate personal protective equipment (PPE) when caring for patients with glyphosate exposure to prevent secondary contamination of healthcare providers. 1
• Ensure adequate ventilation in treatment areas, as glyphosate formulations can pose exposure risks to staff. 1

Decontamination

• Remove all contaminated clothing immediately and perform copious irrigation with soap and water for dermal exposure. 1
• Gastric lavage may be considered in early presentations (within 1-2 hours), but poses significant risk of secondary exposure to healthcare workers from gastric contents. 2, 3
• Healthcare workers performing gastric lavage must use full PPE, as documented cases exist of staff requiring medical treatment after exposure to contaminated gastric contents. 4

Contact Poison Control

• Call the U.S. Poison Control Center at 1-800-222-1222 immediately for expert guidance on case-specific management. 1

Airway and Respiratory Management

• Early endotracheal intubation is critical for patients developing respiratory distress, as respiratory failure accounts for 23.3% of fatalities in glyphosate poisoning. 5
• Patients commonly develop acute respiratory distress syndrome (ARDS) and aspiration pneumonia within hours of ingestion. 2
• Secure the airway early to prevent aspiration, which is a major cause of death. 5

Hemodynamic Support

• Shock is the leading cause of death (58.2% of fatalities) and typically develops early after exposure; prompt and aggressive fluid resuscitation is critical in initial management. 5
• Hypotension often requires vasopressor support with noradrenaline and/or vasopressin infusion. 3
• The hypotension is frequently refractory to standard treatment due to surfactant (POEA)-mediated cardiotoxicity and uncoupling of oxidative phosphorylation. 2

Metabolic and Laboratory Monitoring

Key Laboratory Abnormalities to Monitor

• Severe lactic acidosis develops within hours and requires aggressive correction. 2
• Hyperkalemia is common and may require treatment with calcium gluconate for cardiac membrane stabilization in life-threatening arrhythmias. 6
• Hypokalemia and hypernatremia can also occur and require correction. 2
• Monitor for elevated amylase and ALT, as acute pancreatitis may develop days after ingestion. 7

Renal Support

• Acute kidney injury is common; consider early continuous veno-venous hemodiafiltration (CVVHD) for renal failure and severe metabolic acidosis. 3
• Continuous dialysis methods are preferred over intermittent hemodialysis in hemodynamically unstable patients to avoid worsening hypotension. 8

Adjunctive Therapies

Intravenous Lipid Emulsion

• IV lipid emulsion (20% intralipid 100 mL) has been used successfully in case reports, though evidence is limited to anecdotal reports. 3
• This may be considered in severe, refractory cases given the lipophilic nature of glyphosate formulations.

Sodium Bicarbonate

• Administration of sodium bicarbonate (1-2 mEq/kg IV push) can be considered for severe metabolic acidosis. 6

Prognostic Factors and Risk Stratification

High-Risk Features Requiring ICU Admission

• Age > 50 years, ingested amount > 100 mL, X-ray abnormalities (aspiration, pulmonary edema), and ALT > 40 U/L are independent predictors of serious complications requiring intensive care. 7
• Delayed presentation (longer elapsed time to hospital) is associated with worse outcomes. 5
• Attempted suicide as the reason for exposure correlates with larger ingested volumes and higher mortality. 5

Timeline of Complications

• Most life-threatening complications (shock, respiratory failure, metabolic acidosis, hyperkalemia, seizures) develop within the first 24 hours. 7
• Acute pancreatitis may occur several days after ingestion. 7
• Neurological sequelae, including white matter lesions and development of vigil coma, have been reported in survivors of massive ingestions. 8

Monitoring Duration

• All patients with glyphosate exposure require close observation for at least 48-72 hours, even if initially stable, as delayed complications are common. 1

Critical Pitfalls to Avoid

• Never delay supportive care while awaiting specific laboratory confirmation; treatment is based on clinical presentation. 2, 3
• Do not underestimate the severity based on initial presentation; patients can deteriorate rapidly within 2 hours. 2
• Avoid intermittent hemodialysis in hemodynamically unstable patients; use continuous renal replacement therapy instead. 8
• Do not administer atropine routinely; it is NOT indicated for glyphosate poisoning (unlike organophosphate poisoning) and its use has been associated with worse outcomes in epidemiological studies. 5

Overall Case Fatality Rate

• The case fatality rate for glyphosate-surfactant herbicide poisoning is approximately 7.2%, with shock and respiratory failure being the primary causes of death. 5