What is the management approach for a patient with suspected diquat dibromide poisoning?

Management of Diquat Dibromide Poisoning

Immediately contact your regional poison control center (1-800-222-1222 in the US) as this is the single most critical step in managing diquat poisoning, and prioritize aggressive supportive care as there is no specific antidote and mortality approaches 43% in reported cases. 1, 2

Immediate Stabilization and Resuscitation

Airway and Breathing Management

• Secure the airway immediately if there is altered mental status, respiratory depression, corrosive airway injury (epiglottitis), or inability to protect airway. 1, 3
• Provide 100% oxygen and maintain adequate ventilation, as diquat causes severe oxidative cellular damage requiring maximal oxygen delivery. 1
• Anticipate rapid deterioration—patients may remain asymptomatic for 8-20 hours before sudden onset of multi-organ failure. 3, 4

Circulatory Support

• Establish large-bore IV access immediately and prepare for aggressive fluid resuscitation, as hypovolemic shock from gastrointestinal losses is common. 2
• Administer isotonic crystalloids for hypotension, but monitor carefully for fluid overload given the high risk of acute renal failure. 1, 2
• Prepare for cardiocirculatory collapse and cardiac arrest, which can occur within 20 hours of ingestion—diquat causes myocardial infarction and is one of the most severely affected organs. 4

Gastrointestinal Decontamination

Timing-Dependent Approach

• Consider gastric lavage or activated charcoal ONLY if the patient presents within 1 hour of a life-threatening ingestion (>6 grams of diquat). 2
• Do NOT perform decontamination if the patient presents hours after ingestion with vomiting already present, as absorption has already occurred and these interventions may delay definitive care. 5, 2
• The evidence shows that even diluted solutions (1.84% concentration) can cause systemic toxicity and death. 3

Renal Replacement Therapy

Hemodialysis Indications

• Initiate emergency hemodialysis or continuous renal replacement therapy (CRRT) immediately if acute renal failure develops, as this is of proven value for managing renal failure complications. 2, 6
• However, recognize that hemodialysis and hemoperfusion do NOT remove toxicologically significant amounts of diquat to prevent organ failure or death in severe cases. 2
• Continuous venovenous hemodiafiltration with hemoperfusion has been attempted but does not prevent fatal outcomes. 7

Organ-Specific Monitoring and Management

Gastrointestinal Toxicity

• Expect severe gastrointestinal mucosal ulceration, paralytic ileus, and corrosive lesions of mucosal surfaces. 2, 4
• Administer ondansetron 4-8 mg IV or metoclopramide 10 mg IV for symptomatic vomiting relief. 5
• Monitor for esophagitis and mucositis development, which typically appears 8-20 hours post-ingestion. 3

Cardiovascular Complications

• Monitor continuously for cardiac arrhythmias, myocardial infarction, and cardiocirculatory shock—these are leading causes of death in diquat poisoning. 4
• Prepare for cardiac arrest protocols, as fulminant cardiovascular collapse can occur within 20 hours. 4

Neurological Involvement

• Perform neuroimaging (CT/MRI) if disturbance of consciousness develops, as diquat can cause central pontine myelinolysis and brain stem infarction. 7
• Monitor for coma development in severe cases. 2
• Neurological involvement is relatively rare but carries grave prognosis when present. 7

Renal Toxicity

• Acute renal failure is nearly universal in significant ingestions and typically develops within days. 3, 2, 6
• Monitor renal function closely with serial creatinine and urine output measurements. 2

Diagnostic Confirmation

• Perform qualitative urine testing for diquat to rapidly confirm diagnosis. 2
• Do not delay treatment while awaiting confirmatory testing—clinical suspicion based on history and toxidrome is sufficient to initiate aggressive management. 1

Critical Pitfalls to Avoid

• Never delay poison control consultation—expert toxicology guidance is essential as management is complex and mortality is high. 1, 5
• Do not assume safety based on diluted concentrations—even 1.84% solutions cause systemic toxicity and death. 3
• Do not rely on hemodialysis or hemoperfusion to remove diquat and prevent death—these modalities only manage renal failure complications, not toxin removal. 2
• Never underestimate the asymptomatic period—patients may appear well for 8-20 hours before catastrophic deterioration. 3, 4
• Do not delay intubation in patients with corrosive airway injury (epiglottitis), as airway compromise can be rapid. 3

Prognosis

The mortality rate for diquat poisoning is approximately 43% in reported cases, with death typically occurring from multi-organ dysfunction syndrome involving cardiac, renal, pulmonary, and neurological failure. 2, 4, 7 Fulminant cases may result in death within 20 hours, while others progress over 15-18 days. 4, 7