A 35-year-old female with a family history of unexplained perioperative death (her brother died during surgery 10 years ago) is scheduled for elective hysterectomy. During preoperative counseling, she expresses concern about anesthetic risk. Which of the following is the most appropriate anesthetic plan to minimize the risk of malignant hyperthermia?

Question

Accepted Answer

A. Use propofol for induction, avoid succinylcholine, use rocuronium for muscle relaxation, and employ total intravenous anesthesia (TIVA) with nitrous oxide. ## Risk Stratification and Preoperative Planning

**Key Point:** A positive family history of perioperative death or unexplained anesthetic complications raises strong suspicion for malignant hyperthermia susceptibility (MHS). Preoperative counseling and selection of a safe anesthetic technique are critical.

## MH Triggering Agents vs. Safe Alternatives

| Agent Category | TRIGGERS MH | SAFE |
|---|---|---|
| **Induction agents** | Thiopental | Propofol, etomidate, ketamine |
| **Muscle relaxants** | Succinylcholine | Rocuronium, vecuronium, cisatracurium, atracurium |
| **Volatile anesthetics** | Halothane, isoflurane, desflurane, sevoflurane | None (all volatiles trigger MH) |
| **Opioids** | Safe | Morphine, fentanyl, remifentanil |
| **Nitrous oxide** | Safe | Yes |
| **Local anesthetics** | Safe | Lignocaine, bupivacaine |

**High-Yield:** Succinylcholine and ALL volatile anesthetics (halothane, isoflurane, desflurane, sevoflurane) are absolute contraindications in MH-susceptible patients. Nitrous oxide is safe and can be used.

## Safe Anesthetic Technique for MHS Patients

```mermaid
flowchart TD
  A[MHS patient scheduled for surgery]:::outcome --> B[Avoid ALL volatile anesthetics]:::urgent
  B --> C[Avoid succinylcholine]:::urgent
  C --> D[Use TIVA: propofol + opioid]:::action
  D --> E[Non-depolarizing relaxant: rocuronium/vecuronium]:::action
  E --> F[Nitrous oxide + oxygen acceptable]:::action
  F --> G[Standard monitoring + core temp probe]:::action
  G --> H[Dantrolene & MH cart in OR]:::action
  H --> I[Uneventful anesthesia]:::outcome
```

**Clinical Pearl:** Total intravenous anesthesia (TIVA) using propofol and opioids (remifentanil or fentanyl) is the gold standard for MHS patients. It avoids all volatile agents and provides excellent anesthetic control.

## Why Option 0 Is Correct

- **Propofol:** Safe induction agent; does not trigger MH.
- **Rocuronium:** Non-depolarizing relaxant; safe alternative to succinylcholine.
- **TIVA:** Avoids all volatile anesthetics (the major MH triggers).
- **Nitrous oxide:** Safe and can supplement TIVA.

**Mnemonic:** **SAFE MH** — Succinylcholine Avoided, Fluorinated volatiles Eliminated, Muscle relaxants (non-depolarizing), Hyperthermia monitoring, Anesthesia (total IV)

## Preoperative Considerations

**Key Point:** Patients with suspected or confirmed MHS should:
1. Wear a medical alert bracelet.
2. Undergo genetic testing or caffeine halothane contracture test (CHCT) if diagnosis uncertain.
3. Have dantrolene sodium (36 vials minimum) and emergency equipment in the OR.
4. Receive written counseling about MH risk and safe anesthetic agents.
5. Inform all future anesthesiologists of MHS status.

[cite:Miller's Anesthesia 8e Ch 73; Gupta & Sharma Anesthesia 4e Ch Malignant Hyperthermia]

Answer

B. Perform awake fiberoptic intubation under local anesthesia to avoid general anesthesia entirely

Answer

C. Use propofol induction with succinylcholine, then switch to desflurane for maintenance to minimize MH risk

Answer

D. Use thiopental for rapid sequence induction with succinylcholine, then maintain with isoflurane and nitrous oxide

Explanation

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