Is succinylcholine (a depolarizing neuromuscular blocking agent) safe to use in a burn patient?

Succinylcholine Use in Burn Patients

Succinylcholine is contraindicated in burn patients after the acute phase of injury (approximately 48-72 hours post-burn) due to the risk of potentially fatal hyperkalemia. 1

Mechanism and Risks

Succinylcholine poses significant dangers in burn patients due to several physiological changes:

• Upregulation of acetylcholine receptors: Burns cause proliferation of extrajunctional acetylcholine receptors on the muscle membrane
• Hyperkalemic response: When succinylcholine binds to these upregulated receptors, it triggers massive potassium release that can lead to:
  • Cardiac arrhythmias
  • Cardiac arrest
  • Death

The FDA drug label explicitly states that succinylcholine should be administered with "GREAT CAUTION" to patients during the acute phase of injury following major burns, and is contraindicated after the acute phase 1.

Timeline of Risk

The risk profile changes based on time since burn injury:

• First 24-48 hours: Generally considered safe to use succinylcholine
• After 48-72 hours through 2 years post-burn: Contraindicated due to high risk of hyperkalemia 2
• Peak risk period: 7-10 days after injury 1

The severity of risk correlates directly with:

• Extent of burn (percentage of body surface area affected)
• Time since injury
• Dose of succinylcholine administered

Alternative Approaches

For patients requiring neuromuscular blockade after the initial 48-72 hour window:

1. Use rocuronium as the preferred alternative:

   • High-dose rocuronium (≥0.9 mg/kg) provides comparable intubation conditions 3
   • Does not cause hyperkalemia in burn patients
   • Longer duration of action than succinylcholine

2. Consider having sugammadex available if using rocuronium in emergency situations where rapid reversal might be needed

Special Considerations

• Monitoring: If succinylcholine must be used in the acute phase (<48 hours), continuous ECG monitoring is essential to detect early signs of hyperkalemia
• Dantrolene availability: Ensure dantrolene is readily available when using succinylcholine due to increased risk of malignant hyperthermia in burn patients 4
• Avoid in other high-risk conditions: Similar contraindications exist for patients with:
  • Neuromuscular diseases
  • Extensive denervation of skeletal muscle
  • Upper motor neuron injury
  • Prolonged immobilization 4, 1

Conclusion

The evidence strongly indicates that succinylcholine should be avoided in burn patients beyond the acute phase of injury. The risk of life-threatening hyperkalemia far outweighs any benefit of its short duration of action. Rocuronium represents a safer alternative for these patients when neuromuscular blockade is required.