Should gastric lavage be performed in a patient who ingested a plant-based product containing 20% nitrobenzene in a suicide attempt?

Gastric Lavage Should NOT Be Performed in Nitrobenzene Poisoning

Gastric lavage is contraindicated in this case and should not be performed. Modern toxicology guidelines explicitly recommend against gastric lavage for most poisonings due to serious risks including aspiration, esophageal perforation, and lack of proven benefit, and it is only justified in rare life-threatening cases where the ingested substance is not adsorbed by activated charcoal 1, 2, 3.

Immediate Management Priorities

Life-Threatening Complications First

• Call emergency services immediately and implement life-support measures including airway protection, breathing support, and circulatory support as the first priority 1, 3.
• Contact a Poison Control Center urgently to guide specific management of nitrobenzene toxicity 1, 2.
• Assess for methemoglobinemia, which is the primary life-threatening complication of nitrobenzene poisoning, presenting with cyanosis, chocolate-brown blood, and hypoxia that does not improve with supplemental oxygen 4, 5, 6.

Why Gastric Lavage is Contraindicated

• Gastric lavage carries serious risks including aspiration pneumonitis, esophageal perforation, and mediastinitis, and is only justified in extremely rare cases where life is at immediate risk from a substance NOT adsorbed by activated charcoal 2, 3.
• The risk-benefit ratio does not favor gastric lavage in nitrobenzene poisoning, as activated charcoal is the preferred decontamination method 2, 3.

Appropriate Decontamination Strategy

Activated Charcoal Instead

• Administer activated charcoal (1 g/kg orally) if the patient presents within 1-2 hours of ingestion, provided the patient is fully conscious and can swallow safely without aspiration risk 7, 2, 3.
• Activated charcoal is effective at adsorbing many toxins and should be the first-line gastrointestinal decontamination method when indicated 2, 3.
• Do not give anything by mouth unless specifically advised by Poison Control, as this may induce vomiting and increase aspiration risk 8, 1.

Specific Treatment for Nitrobenzene Toxicity

Methemoglobinemia Management

• Administer 1% methylene blue intravenously (1-2 mg/kg over 5 minutes) as the specific antidote for symptomatic methemoglobinemia when methemoglobin levels exceed 20-30% or when the patient is symptomatic 4, 5, 9.
• Provide supplemental high-flow oxygen and consider hemodynamic and ventilatory support in severe cases 4, 5.
• Vitamin C (ascorbic acid) can be added as adjunctive therapy to help reduce methemoglobin levels 5.

Monitoring and Supportive Care

• Monitor for delayed hemolytic anemia, which can occur 24-48 hours after methylene blue treatment 4, 9.
• Obtain laboratory evaluation including complete blood count, arterial blood gases, methemoglobin levels (if co-oximeter available), liver and renal function tests 2, 5.
• In resource-limited settings without co-oximeter, diagnose methemoglobinemia clinically by chocolate-brown blood appearance and failure of oxygen saturation to improve despite supplemental oxygen 5.

Critical Pitfalls to Avoid

• Never perform gastric lavage routinely - it increases complications without proven benefit in most poisoning cases 2, 3.
• Do not delay methylene blue administration while waiting for methemoglobin levels if clinical presentation is consistent with significant methemoglobinemia 5.
• Avoid ipecac syrup or induced vomiting under any circumstances 3.
• Do not underestimate severity based on initial presentation - nitrobenzene can cause rapid deterioration and toxic brain injury 6.

Psychiatric Evaluation

• Arrange psychiatric evaluation and monitoring since this was a suicide attempt, and assess short-term relapse risk even after medical stabilization 2, 3.
• Hospital admission should be maintained until acute suicide risk has subsided 3.