Which of the following drugs is a safe alternative for anesthesia in a patient with confirmed malignant hyperthermia susceptibility?

Explanation

## Safe Anesthesia in Malignant Hyperthermia Susceptible Patients **Key Point:** Patients with confirmed or suspected MH susceptibility must avoid all volatile anesthetics and succinylcholine. Safe alternatives include total intravenous anesthesia (TIVA) with propofol, non-depolarizing neuromuscular blockers, and nitrous oxide. ### Classification of Anesthetic Agents | Agent Class | Safe in MH? | Examples | Rationale | | --- | --- | --- | --- | | **Volatile anesthetics** | ❌ NO | Halothane, isoflurane, desflurane, sevoflurane | Trigger agents — cause uncontrolled Ca²⁺ release | | **Succinylcholine** | ❌ NO | Depolarizing agent | Trigger agent; causes sustained depolarization | | **Propofol (IV)** | ✓ YES | Induction and maintenance | Safe; does not trigger MH | | **Nitrous oxide** | ✓ YES | Adjunct gas | Safe; not a trigger | | **Opioids** | ✓ YES | Fentanyl, morphine, remifentanil | Safe; no trigger potential | | **Non-depolarizing blockers** | ✓ YES | Rocuronium, atracurium, vecuronium | Safe; do not trigger MH | | **Benzodiazepines** | ✓ YES | Midazolam | Safe for premedication | | **Local anesthetics** | ✓ YES | Lidocaine, bupivacaine | Safe; no trigger potential | **High-Yield:** The mnemonic **"SAFE"** for MH-safe anesthesia: - **S**uccinylcholine — AVOID - **A**void volatile anesthetics - **F**entanyl (and opioids) — SAFE - **E**tomidate/Propofol — SAFE (IV agents) **Mnemonic:** **NEVER** in MH-susceptible patients: - **N**itrous oxide — actually SAFE; the mnemonic refers to **Neuroleptics** (avoid some) and **Neuromuscular blockers (depolarizing)** — AVOID - **E**ther-based agents (volatiles) — AVOID - **V**apor anesthetics — AVOID - **E**xcessive heat — avoid - **R**igidity triggers — succinylcholine AVOID Better mnemonic: **STOP** triggering agents: - **S**uccinylcholine — AVOID - **T**rigger volatiles (halothane, isoflurane, desflurane, sevoflurane) — AVOID - **O**ther depolarizers — AVOID - **P**ropofol — SAFE ### Safe Anesthetic Technique for MH-Susceptible Patient 1. **Premedication:** Benzodiazepines (midazolam), anticholinergics 2. **Induction:** Propofol or etomidate IV 3. **Maintenance:** Propofol infusion (TIVA) + opioids + nitrous oxide 4. **Neuromuscular blockade:** Non-depolarizing agents (rocuronium, vecuronium, atracurium) 5. **Avoid:** All volatile anesthetics, succinylcholine 6. **Monitoring:** Continuous capnography, core temperature, urine output, CK levels postoperatively **Clinical Pearl:** Even in MH-susceptible patients, nitrous oxide is safe and can be used as an adjunct. The key is avoiding the two main trigger classes: volatile anesthetics and succinylcholine. ## Why the Correct Answer is Correct Propofol is a safe intravenous induction and maintenance agent with no trigger potential in MH-susceptible patients. Nitrous oxide is also safe (it is NOT a volatile anesthetic in the triggering sense — it is an inert gas). Fentanyl is a safe opioid analgesic. This combination represents a standard TIVA technique for MH-susceptible patients.