What is the treatment for cardiac arrest due to propane inhalation?

Treatment of Cardiac Arrest Due to Propane Inhalation

Follow standard BLS and ACLS protocols immediately, with critical modifications: avoid sympathomimetic drugs during resuscitation and consider early beta-blocker administration to protect the catecholamine-sensitized myocardium. 1, 2

Immediate Resuscitation

Standard CPR and Defibrillation

• Begin high-quality CPR immediately with chest compressions at least 5 cm deep at a rate of 100-120/minute, allowing complete chest recoil between compressions 3
• Apply an automated external defibrillator (AED) or manual defibrillator as soon as available while continuing CPR 3
• The primary mechanism of cardiac arrest from propane inhalation is ventricular arrhythmia due to myocardial sensitization to catecholamines 2, 4, 5
• Minimize interruptions in chest compressions to maintain coronary and cerebral perfusion 3

Airway Management Considerations

• Exercise caution with early intubation if propane/butane inhalation is confirmed, as these agents can cause severe laryngeal edema and laryngospasm 2
• If advanced airway is necessary, establish it using standard techniques and confirm placement with waveform capnography 3
• After advanced airway placement, provide 1 breath every 6 seconds (10 breaths/min) with continuous chest compressions 3

Critical Medication Modifications

Avoid Sympathomimetic Agents

• Do not use standard epinephrine or other sympathomimetic drugs during the initial resuscitation, as volatile hydrocarbons sensitize the myocardium to catecholamines and may precipitate or worsen fatal arrhythmias 2
• This represents a major deviation from standard ACLS protocols but is essential given the pathophysiology of propane-induced cardiac arrest 2

Consider Beta-Blockade

• Administer beta-adrenergic blocking agents early in the resuscitation process to protect the catecholamine-sensitized heart 2
• This counteracts the arrhythmogenic effects of endogenous catecholamine release triggered by the stress response 2, 4

Arrhythmia Management

• Treat cardiac arrhythmias conventionally with antiarrhythmic agents 2
• For shock-refractory ventricular fibrillation/pulseless ventricular tachycardia, consider amiodarone (300 mg IV/IO bolus, then 150 mg) or lidocaine (1-1.5 mg/kg IV/IO) 3
• These agents do not have the sympathomimetic properties that would worsen catecholamine sensitization 2

Identify and Treat Reversible Causes

Specific Considerations for Propane Inhalation

• Assess for coronary vasospasm as a contributing factor, as butane/propane can cause intense coronary artery spasm leading to myocardial infarction even with normal coronary arteries 6
• Evaluate for tension pneumothorax, which should be treated immediately if present 1, 3
• Monitor for laryngeal edema and airway obstruction specific to butane/propane exposure 2
• Consider aspiration of vomit as a contributing factor to respiratory compromise 2

Standard Reversible Causes

• Address the remaining "H's and T's": hypovolemia, hypoxia, hydrogen ion (acidosis), hypo/hyperkalemia, hypothermia, cardiac tamponade, toxins, and thrombosis 3

Post-Resuscitation Care (If ROSC Achieved)

Immediate Post-ROSC Management

• Recognize ROSC by presence of pulse, blood pressure, and abrupt sustained increase in PETCO2 (typically >40 mm Hg) 3
• Optimize cardiopulmonary function and vital organ perfusion 3
• Evaluate for myocardial injury, as propane/butane inhalation can cause acute myocardial infarction with angiographically normal coronary arteries due to severe coronary vasospasm 6

Cardiac Evaluation

• Perform urgent cardiac catheterization if acute coronary syndrome is suspected, recognizing that coronary arteries may appear normal despite significant myocardial injury 6
• Obtain electrocardiogram and cardiac biomarkers to assess for myocardial infarction 6
• Arrange cardiology follow-up, as patients with myocardial injury from volatile substance inhalation may have increased long-term cardiac risk 1

Neuroprotective Measures

• Control body temperature to optimize neurological recovery; consider therapeutic hypothermia (32-34°C) for comatose survivors 3
• Titrate inspired oxygen to achieve arterial oxygen saturation of 94% to avoid oxygen toxicity 3
• Target ventilation to achieve PETCO2 of 35-40 mm Hg or PaCO2 of 40-45 mm Hg 3
• Elevate head of bed 30° if tolerated to reduce cerebral edema 3

Critical Pitfalls to Avoid

• The most important pitfall is administering standard epinephrine or other sympathomimetic vasopressors, which can worsen arrhythmias in the catecholamine-sensitized myocardium 2
• Do not delay resuscitation for toxicological confirmation; clinical history of propane inhalation is sufficient to modify treatment 2
• Do not assume coronary arteries are normal if myocardial infarction is suspected; severe vasospasm can occur with angiographically normal vessels 6
• Resuscitation from propane-induced cardiac arrest is rare since most deaths are unwitnessed, emphasizing the importance of immediate bystander CPR 2

Prognosis

• Survival from cardiac arrest due to volatile substance abuse is extremely rare, as the majority of deaths are unwitnessed 2
• Even with witnessed arrest and immediate resuscitation, outcomes remain poor due to the severe myocardial sensitization and potential for recurrent arrhythmias 2, 4
• Patients under psychiatric treatment with QT-prolonging medications may have an even higher risk profile due to synergistic arrhythmogenic effects 4