What is the appropriate management of acute glyphosate exposure, including decontamination, supportive care, and indications for advanced interventions?

Management of Acute Glyphosate Exposure

Glyphosate poisoning requires immediate aggressive supportive care with early intubation for severe cases, as there is no specific antidote; intravenous lipid emulsion may be considered for life-threatening cardiovascular collapse based on emerging evidence.

Immediate Assessment and Risk Stratification

The volume ingested is the single most important prognostic factor. Ingestion of >85 mL of concentrated formulation (typically 41% glyphosate) is likely to cause significant toxicity in adults, with mortality risk increasing substantially with volumes >500 mL 1, 2. Blood glyphosate concentrations correlate with severity: mild-moderate poisoning averages 61 mg/L (range 0.6-150 mg/L), while fatal cases average 4146 mg/L (range 690-7480 mg/L) 2. Advancing age independently worsens prognosis 1.

Healthcare Worker Protection

All staff must don gloves and protective clothing before patient contact to prevent secondary exposure. 3 Although the risk of significant secondary injury from glyphosate is lower than with organophosphates, healthcare workers have experienced transient symptoms from contact with contaminated patients when personal protective equipment was not used 3. Ensure adequate ventilation of treatment areas 3.

Decontamination Protocol

Dermal Exposure

• Remove all contaminated clothing immediately outside the treatment area 4
• Wash exposed skin thoroughly with soap and water 1
• For eye exposure, irrigate with copious tepid water for at least 15 minutes 4

Gastrointestinal Decontamination

• Do not induce vomiting 4
• Gastric lavage is discouraged due to risk of secondary staff exposure and lack of proven benefit 5
• Consider activated charcoal only if presentation is within 1 hour of ingestion and the patient can protect their airway, though efficacy for glyphosate is uncertain 5
• Do not administer anything by mouth unless specifically directed by poison control 4

Airway and Respiratory Management

Provide early endotracheal intubation for: 4

• Respiratory distress
• Impaired consciousness
• Hemodynamic instability
• Severe metabolic acidosis

Avoid succinylcholine and mivacurium for intubation, as their effects are unpredictable in the setting of potential cholinergic effects; use rocuronium 0.6 mg/kg instead 3. Once intubated, use low tidal-volume ventilation (≤6 mL/kg ideal body weight) with moderate PEEP to reduce ventilator-induced lung injury 6. Target normoventilation with PaCO₂ 5.0-5.5 kPa; avoid hyperventilation as it worsens tissue perfusion and increases mortality 6.

Cardiovascular Support

Initiate aggressive fluid resuscitation immediately: administer 30 mL/kg isotonic crystalloid bolus within the first hour 5. For persistent hypotension despite adequate fluid resuscitation, use vasopressors (noradrenaline and vasopressin) 7. Continuous cardiac monitoring is essential, as bradycardia and ventricular arrhythmias often precede death 1. Treat dysrhythmias according to standard ACLS protocols 4.

Metabolic Management

For severe metabolic acidosis (pH <7.1 or bicarbonate <10 mEq/L): administer sodium bicarbonate 1-2 mEq/kg IV push 5. Monitor for hyperkalaemia, which occurs commonly in severe poisoning 1, 2. Keep calcium gluconate 100-200 mg/kg on standby for life-threatening arrhythmias or hyperkalemia 5.

Renal and Hepatic Monitoring

Renal and hepatic impairment are frequent and usually reflect reduced organ perfusion 1. Monitor creatine kinase and potassium serially to detect rhabdomyolysis, which can develop from calcium-mediated myonecrosis 3, 6. If myoglobinuria develops, provide vigorous hydration and consider urine alkalinization 5. Hemodialysis may be required for renal failure but does not remove glyphosate itself 5.

Advanced Interventions

Intravenous Lipid Emulsion Therapy

Consider ILE for life-threatening cardiovascular collapse refractory to standard resuscitation. The 2015 American Heart Association guidelines note that patients with glyphosate-surfactant herbicide ingestion treated with ILE had less hypotension and fewer arrhythmias than historic controls, though there was no difference in survival outcomes 3.

ILE dosing protocol: 3

• Initial bolus: 1.5 mL/kg lean body mass of 20% lipid emulsion over 1 minute
• Followed by infusion: 0.25 mL/kg per minute for 30-60 minutes
• May repeat bolus once or twice for persistent cardiovascular collapse
• Maximum total dose: 10 mL/kg over first hour

One case report documented successful treatment with 100 mL of 20% intralipid in a patient requiring mechanical ventilation and vasopressor support 7.

Continuous Renal Replacement Therapy

Continuous veno-venous hemodiafiltration may be employed for secondary renal complications and management of severe metabolic derangements, though it does not eliminate glyphosate 7.

Seizure Management

For seizures or severe agitation: administer benzodiazepines—midazolam 0.05-0.1 mg/kg IV or diazepam as first-line agents 4.

Monitoring for Delayed Complications

Observe for delayed neuromuscular weakness that may appear up to 4 days after exposure, potentially requiring prolonged ventilatory support 3, 6. Gastrointestinal corrosive effects are common, with mouth, throat, and epigastric pain and dysphagia frequently reported 1. Severe cases may develop esophageal and tracheal scar contractures requiring reconstructive surgery 8.

Critical Pitfalls to Avoid

• Do not delay basic supportive care (fluid resuscitation, vasopressors, intubation) while pursuing advanced therapies 5
• Do not treat as organophosphate poisoning—atropine and pralidoxime have no role in glyphosate toxicity 5
• Do not use standard oxygen supplementation protocols for paraquat if co-ingestion is suspected; glyphosate itself does not require restricted oxygen 4
• Do not underestimate toxicity based on "low toxicity" classification—concentrated formulations can cause severe systemic toxicity and death 1, 2
• Provide ICU-level care for at least 48-72 hours for all significant exposures 5

Disposition

All patients with intentional ingestion of concentrated formulations require ICU admission regardless of initial presentation, as severe complications including pulmonary edema, shock, arrhythmias, and multi-organ failure may develop over hours 1, 2. Asymptomatic patients with minimal exposure may be observed for 6-8 hours and discharged if they remain completely asymptomatic with normal vital signs and laboratory parameters.