Can rocuronium (a non-depolarizing neuromuscular blocking agent) trigger malignant hyperthermia?

Rocuronium and Malignant Hyperthermia

Rocuronium is not considered a primary trigger for malignant hyperthermia (MH), though rare case reports suggest a possible association in certain circumstances.

Established MH Triggers vs. Non-Depolarizing Muscle Relaxants

The European Malignant Hyperthermia Group (EMHG) guidelines clearly identify the established triggers for MH:

• Known triggers: Volatile anesthetic agents (sevoflurane, desflurane, isoflurane, halothane) and the depolarizing muscle relaxant succinylcholine 1, 2
• Non-triggering agents: Non-depolarizing muscle relaxants like rocuronium are generally considered safe in MH-susceptible patients 3, 4

Evidence Regarding Rocuronium and MH

The FDA label for rocuronium specifically addresses MH risk:

• "Rocuronium bromide has not been studied in MH-susceptible patients. In an animal study in MH-susceptible swine, the administration of rocuronium bromide injection did not appear to trigger malignant hyperthermia." 5

However, there are isolated case reports suggesting a potential association:

• A 2012 report described two cases of delayed-onset MH suspected to be related to rocuronium use, with symptoms developing approximately 4 days after administration 6

Clinical Implications and Recommendations

When managing MH-susceptible patients:

1. Avoid established triggers: All volatile anesthetics and succinylcholine must be strictly avoided 1, 2

2. Use safe alternatives:

   • Regional or local anesthesia when appropriate 2
   • Total intravenous anesthesia (TIVA) when general anesthesia is required 2
   • Non-depolarizing muscle relaxants like rocuronium are generally considered safe options 5, 3

3. Prepare for potential MH crisis:

   • Ensure dantrolene availability (36-48 vials) wherever MH-triggering drugs are used 1, 7
   • Have a protocol in place for rapid intervention if MH is suspected

Important Considerations and Caveats

• Variable penetrance: MH susceptibility shows variable penetrance, meaning susceptible individuals may have previously tolerated trigger agents without developing MH 1, 2, 8

• Monitoring vigilance: Even when using non-triggering agents like rocuronium, maintain vigilance for early signs of MH (unexplained increase in end-tidal CO2, tachycardia, rigidity) 1

• Rare associations: While extremely rare, be aware of isolated reports suggesting potential association between rocuronium and delayed-onset MH-like reactions 6

• Machine preparation: When administering anesthesia to MH-susceptible patients, ensure proper preparation of the anesthesia machine through thorough flushing or use of activated charcoal filters 1, 2

The overwhelming evidence and guidelines support that rocuronium is generally safe for use in MH-susceptible patients, though vigilance should always be maintained during any anesthetic procedure.