Should gastric lavage be performed in chlorpyrifos (Celphos) poisoning?

Gastric Lavage in Chlorpyrifos (Celphos) Poisoning

Gastric lavage should NOT be performed routinely in chlorpyrifos (Celphos) poisoning and should be avoided in most cases, as there is no evidence it improves clinical outcomes and it poses significant risks to both patients and healthcare workers. 1, 2, 3, 4

Primary Treatment Approach

Immediate pharmacologic antidotal therapy takes absolute priority over any gastrointestinal decontamination attempts. The cornerstone of management includes:

• Atropine (first-line): Adults 1-2 mg IV bolus, repeat every 5 minutes titrating to control bronchorrhea, bronchospasm, and bradycardia; children 0.02 mg/kg IV (minimum 0.1 mg, maximum 0.5 mg per dose). Typical cumulative dose may reach 10-20 mg in first 2-3 hours, sometimes up to 50 mg within 24 hours 1

• Pralidoxime (Class 2a, Level A): Adults 1-2 g IV loading dose over 15-30 minutes, then continuous infusion 400-600 mg/h; children 25-50 mg/kg IV loading dose (max 2 g) over 15-30 minutes, then infusion 10-20 mg/kg/h. Must be administered early before irreversible "aging" of inhibited acetylcholinesterase 1

• Benzodiazepines for seizure control: Diazepam 0.2 mg/kg IV or midazolam 0.05-0.1 mg/kg IV 1

• Early airway protection with endotracheal intubation for compromised airway or severe poisoning; avoid succinylcholine and mivacurium 1

Why Gastric Lavage Should Be Avoided

Lack of Clinical Benefit

• No controlled studies demonstrate that gastric lavage improves clinical outcomes in organophosphate poisoning 3, 4

• The amount of toxin removed by gastric lavage is highly variable and diminishes rapidly with time 3

• In a large poisoning cohort, gastric lavage was performed in only 10.5% of cases, reflecting its limited real-world applicability 1, 2

Significant Risks to Healthcare Workers

• Healthcare workers face high risk of secondary organophosphate exposure during gastric lavage, with documented cases requiring emergency treatment including atropine, pralidoxime, and prolonged intubation 1

• Failure to use full personal protective equipment (PPE) when handling contaminated gastric contents has led to severe illness in caregivers 1

• Mandatory PPE (gloves, gowns, eye protection, respirators) is required for all staff exposed to emesis or gastric aspirate 1

Patient Complications

• Gastric lavage carries significant morbidity including aspiration pneumonia, cardiac dysrhythmias, hypoxia, laryngospasm, esophageal or gastric perforation, and electrolyte imbalances 2, 3, 4

• The procedure is contraindicated if airway protective reflexes are lost (unless patient is intubated) 3

Recommended Decontamination Strategy

External decontamination is the only routinely recommended gastrointestinal intervention:

• Prompt removal of contaminated clothing and thorough skin irrigation with soap and water (brush off powders before washing) for all patients with organophosphate exposure, with PPE worn by responders 1

• Gastric lavage and activated charcoal should NOT be performed unless explicitly directed by a poison control center 1

• Routine oral decontamination offers no proven advantage and may provoke emesis or aspiration 1

Extremely Limited Exceptions

If gastric lavage is considered at all (which should be rare), it may only be attempted when ALL of the following criteria are met:

• Patient has ingested a potentially lethal amount 2, 3, 5
• Presentation within 1-2 hours of ingestion 2, 3, 5
• Airway is protected (intubated) 2, 3
• Trained personnel are available 2, 4
• Full PPE is available for all staff 1

Even when these criteria are met, clinical benefit remains unproven 3, 4

Critical Pitfalls to Avoid

• Never delay atropine, pralidoxime, or benzodiazepine therapy to perform gastric lavage—immediate antidotal treatment is paramount 1

• Never conduct gastric lavage without full PPE for all involved staff—protection of caregivers is essential 1

• Do not rely on gastric lavage as a substitute for aggressive pharmacologic management—antidotes remain the cornerstone of care 1

Note on Conflicting Evidence

One small Indian case series (33 patients) reported 42% survival using extensive gastric lavage with coconut oil and sodium bicarbonate mixture 6. However, this uncontrolled study has significant methodological flaws, lacks a comparison group, and contradicts international consensus guidelines from the American Academy of Clinical Toxicology and European Association of Poisons Centres and Clinical Toxicologists 3, 4. The weight of high-quality evidence strongly favors avoiding routine gastric lavage 1, 2, 3, 4.