What is the management for a patient who collapsed after ingesting cough syrup containing dextromethorphan (cough suppressant)?

Management of Collapse After Dextromethorphan-Containing Cough Syrup Ingestion

Immediately initiate standard Advanced Cardiac Life Support (ACLS) protocols with airway management, circulatory support, and continuous cardiac monitoring, while simultaneously investigating for potential toxic ingestion, drug interactions (particularly with MAO inhibitors), or underlying cardiac pathophysiology. 1

Immediate Resuscitation and Stabilization

Primary Assessment and Support

• Establish airway patency and provide supplemental oxygen or mechanical ventilation if needed to maintain adequate oxygenation during cardiovascular collapse 1
• Initiate continuous cardiac monitoring to detect dysrhythmias, QRS prolongation, or other conduction abnormalities that may indicate cardiotoxicity 1
• Secure IV access and begin fluid resuscitation for hypotension while preparing for more advanced interventions if standard measures fail 1

Critical History and Physical Examination

• Determine exact cough syrup formulation and quantity ingested, as combination products may contain paracetamol, antihistamines, or decongestants requiring specific management 2
• Identify concurrent medications, particularly MAO inhibitors, as co-administration with dextromethorphan can cause life-threatening serotonin syndrome with cardiovascular collapse 3
• Assess for signs of serotonin syndrome: hyperthermia, muscle rigidity, altered mental status, autonomic instability, and hyperreflexia 3
• Look for evidence of sodium channel blocker toxicity: QRS prolongation >120 ms, right bundle branch pattern, hypotension 1

Advanced Cardiovascular Support

For Refractory Shock or Cardiac Arrest

• Consider VA-ECMO for persistent cardiogenic shock or cardiac arrest due to poisoning that is not responsive to maximal treatment measures (Class 2a recommendation) 1
• VA-ECMO is reasonable for persistent dysrhythmias due to poisoning when other treatment measures fail, providing forward blood flow to allow poison elimination 1
• Poisoned patients managed with VA-ECMO have lower mortality than other VA-ECMO patients and lower mortality compared with poisoned patients treated with standard critical care alone 1

Temperature Management

• If hyperthermia is present (suggesting serotonin syndrome or sympathomimetic toxicity), initiate aggressive cooling with ice water immersion, which cools more rapidly than cooling blankets, cold packs, or endovascular devices 1

Vasodilator Therapy

• For evidence of coronary vasospasm or sympathomimetic toxicity, administer vasodilators including nitrates and α-adrenergic receptor antagonists to reverse electrocardiographic and biochemical markers of ischemia 1

Specific Antidotal and Supportive Measures

For Sodium Channel Blocker Toxicity (if combination product)

• Administer sodium bicarbonate for cardiac arrest or life-threatening cardiac conduction delays (QRS prolongation >120 ms) due to sodium channel blocker overdose (Class 2a recommendation) 1
• Sodium bicarbonate boluses achieve serum alkalization and are the standard therapy for hypotension or cardiotoxicity from sodium channel blocker poisoning 1

For Serotonin Syndrome

• Discontinue all serotonergic agents immediately 3
• Administer benzodiazepines for agitation and muscle rigidity rather than physical restraints, as sustained restraint use without effective sedation is associated with death in patients with severe agitation 1
• Consider cyproheptadine (serotonin antagonist) for moderate to severe cases

Mechanical Circulatory Support Considerations

• Mechanical circulatory support including VA-ECMO and intra-aortic balloon pump has been used successfully to support cardiac output in patients in cardiogenic shock while stress (takotsubo) cardiomyopathy resolves 1
• Stress cardiomyopathy can be fatal but often spontaneously resolves in days to weeks with circulatory support 1

Monitoring and Ongoing Management

Laboratory and Diagnostic Evaluation

• Obtain comprehensive metabolic panel, cardiac biomarkers, and toxicology screen to identify co-ingestions and assess end-organ damage 1
• Perform serial ECGs to monitor for conduction abnormalities and QRS duration 1
• Monitor core temperature continuously if hyperthermia is present 1

Disposition and Follow-up

• Admit to intensive care unit for continuous monitoring until cardiovascular stability is achieved and toxin elimination is complete 1
• The natural course of drug overdose is recovery due to renal, hepatic, or extracorporeal removal of the poison in the absence of permanent end-organ damage 1

Critical Pitfalls to Avoid

• Do not delay advanced circulatory support (VA-ECMO) in refractory shock, as early initiation is associated with improved survival in cardiotoxic poisoning 1
• Do not use physical restraints without effective sedation in agitated patients, as this is associated with death 1
• Do not miss MAO inhibitor co-administration, which dramatically alters dextromethorphan safety profile and requires specific management 3
• Do not assume dextromethorphan alone caused collapse—investigate for combination product ingredients (paracetamol, antihistamines, decongestants) that may require specific interventions 2
• Do not overlook underlying cardiac conditions that may have been unmasked or exacerbated by the medication 1