How should chlormequat poisoning be managed in a patient?

Management of Chlormequat Poisoning

Chlormequat poisoning should be managed as a cholinergic crisis with immediate atropine administration, aggressive supportive care, and early intubation, as this toxin causes life-threatening cardiac dysrhythmias and can result in death within one hour of ingestion.

Immediate Recognition and Severity Assessment

Chlormequat poisoning presents with cholinergic crisis symptoms despite not inhibiting cholinesterase activity—it acts directly on nicotinic and muscarinic receptors 1. Key clinical features include:

• Salivation, diaphoresis, and bronchorrhea 2
• Bradycardia and cardiac dysrhythmias (ventricular fibrillation progressing to asystole) 2
• Visual disturbances and seizures 2
• Marked pulmonary edema 2
• Death can occur within one hour of ingestion, making this an extreme medical emergency 1

Primary Treatment: Atropine Administration

Administer high-dose atropine immediately using the same protocol as for organophosphate poisoning, as chlormequat produces identical cholinergic symptoms 3:

• Initial dose: 1-2 mg IV in adults (0.02 mg/kg in children), doubled every 5 minutes until full atropinization is achieved 3
• Titration endpoints: Clear chest on auscultation, heart rate >80/min, systolic blood pressure >80 mm Hg 3
• Maintenance infusion: 10-20% of the total loading dose per hour, up to 2 mg/h in adults 3
• Much higher doses are required than for typical bradycardia—do not underdose 3

Airway Management

Early endotracheal intubation is critical given the rapid progression to respiratory failure and cardiac arrest 3, 2:

• Establish airway and provide bag-mask ventilation immediately 3
• Proceed to endotracheal intubation when appropriate, particularly given the risk of pulmonary edema 2
• Avoid succinylcholine and mivacurium for intubation, as these neuromuscular blockers are metabolized by cholinesterase and are contraindicated in cholinergic poisoning 3

Seizure Management

Administer benzodiazepines for seizures 3:

• Diazepam is first-line 3
• Midazolam is an alternative 3
• Seizures are a common feature of chlormequat poisoning and indicate severe toxicity 2

Cardiac Monitoring and Dysrhythmia Management

Chlormequat causes fatal cardiac dysrhythmias, particularly ventricular fibrillation and asystole 4, 2:

• Continuous cardiac monitoring is mandatory 4, 2
• Be prepared for immediate ACLS protocols 4, 2
• Death from cardiac arrest following chlormequat injection or ingestion is well-documented 4, 2

Decontamination (If Applicable)

For dermal exposure, immediate decontamination is essential 3:

• Remove all contaminated clothing 3
• Thoroughly wash skin with soap and water 3
• Use appropriate personal protective equipment when caring for exposed patients to prevent secondary contamination 3

Supportive Care

• Manage pulmonary edema aggressively, as this is a prominent autopsy finding 2
• Provide fluid resuscitation as needed for hypotension 3
• Monitor for and treat metabolic derangements 2

Critical Pitfalls to Avoid

• Do not delay atropine administration—chlormequat poisoning can be fatal within one hour 1
• Do not use standard bradycardia doses of atropine—much higher doses are required for cholinergic crisis 3
• Do not assume cholinesterase inhibitor antidotes will work—pralidoxime is NOT indicated, as chlormequat does not inhibit cholinesterase 1
• Do not underestimate severity—all seven fatal cases in one case series died rapidly, confirming the extreme gravity of this poisoning 1

Prognosis

Chlormequat poisoning carries extremely high mortality when ingested or injected 4, 2, 1. The route of administration (oral, subcutaneous injection) has been confirmed in fatal cases through detection of chlormequat in blood (2.25 mg/L), urine (4.45 mg/L), and tissue samples 4. Survival depends on immediate recognition and aggressive atropine therapy before cardiac arrest occurs 2, 1.