Nelson Textbook of Pediatrics 22nd Edition — Hypermetabolic crisis triggered by volatile anesthetics (halothane, sevoflurane, desflurane) and succinylcholine. RYR1 (19q13) in 75%, also CACNA1S. Associated with central core disease, King-Denborough syndrome, STAC3 myopathy. Acute treatment: dantrolene 2.5 mg/kg IV, cooling, hyperventilation. Prevention: total intravenous anesthesia (TIVA), avoid triggers.
🌐 paeds.online — Pakistan's Pediatric Platform| Gene | Locus | Protein | Frequency | Associated Myopathy |
|---|---|---|---|---|
| RYR1 | 19q13.1 | Ryanodine receptor (Ca2+ release channel) | ~75% | Central core disease, multiminicore, King-Denborough |
| CACNA1S | 1q32 | Dihydropyridine receptor (L-type Ca channel) | ~1-5% | Hypokalemic periodic paralysis (rare MH) |
| STAC3 | 12q13 | STAC3 (excitation-contraction coupling) | Rare | Native American myopathy (Bailey-Bloch) |
| Class | Specific Agents | Safe Alternatives |
|---|---|---|
| Volatile anesthetics | Halothane, sevoflurane, desflurane, isoflurane, enflurane | Total intravenous anesthesia (TIVA): propofol, etomidate, ketamine, benzodiazepines, nondepolarizing muscle relaxants (rocuronium, vecuronium, cisatracurium) |
| Depolarizing muscle relaxant | Succinylcholine (can cause masseter spasm, hyperkalemia) | Nondepolarizing muscle relaxants (rocuronium, vecuronium) |
| Others | None consistently; local anesthetics, nitrous oxide are safe | — |
Immediate: 1) Call for help, 2) Discontinue all triggering agents, 3) Administer dantrolene 2.5 mg/kg IV bolus, repeat every 5-10 min up to 10 mg/kg, 4) Hyperventilate with 100% O2 (high flow), 5) Active cooling (ice packs, cold IV fluids, lavage), 6) Treat hyperkalemia (insulin/glucose, calcium), 7) Correct metabolic acidosis (bicarbonate if pH <7.2), 8) Monitor for recurrence (consider dantrolene infusion 1-2 mg/kg every 6 hours).
Laboratory: ABG (metabolic/respiratory acidosis), electrolytes (hyperkalemia), CK, myoglobin, coagulation profile (DIC).