This handout is for malignant hyperthermia crisis. Your care team identified this based on: unexplained rising etco2 despite increased minute ventilation (mhaus 2023).
Other reasons your team may use this plan: masseter muscle rigidity / generalized rigidity after succinylcholine (mhaus 2023); rapid rise in core temperature (>=1-2c in 5 min, late finding) (mhaus 2023); prior mh event, known ryr1/cacna1s variant, or first-degree relative susceptible (riazi 2018).
Take these medications exactly as prescribed. Do not stop or change a dose without talking to your provider.
| Medication | Starting dose | How | When | What it does |
|---|---|---|---|---|
| discontinue_volatile_anesthetics_immediately | STOP all sevoflurane/isoflurane/desflurane/halothane | inhaled | immediate | Removing trigger gas halts ongoing calcium release at the ryanodine receptor (MHAUS 2023) |
| discontinue_succinylcholine_and_avoid_redose | DO NOT redose succinylcholine | IV | immediate | Succinylcholine is a depolarizing trigger; switch to non-depolarizing NMB (rocuronium/vecuronium) (MHAUS 2023) |
| switch_to_tiva_propofol_remifentanil | Propofol infusion + opioid (remifentanil or fentanyl) | IV | continuous | Maintain anesthesia without halogenated agents (MHAUS 2023) |
| hyperventilate_100_percent_o2_clean_circuit | 100% FiO2 at >=10 L/min flush; consider activated charcoal filters on anesthesia circuit | inhaled | continuous | Wash out residual volatile; supports increased metabolic O2 demand (MHAUS 2023) |
| call_mhaus_hotline_24_7 | MHAUS Hotline 1-800-644-9737 (US/Canada) | phone | once | Live expert MH guidance during crisis (MHAUS 2023) |
Plan: Malignant Hyperthermia Crisis — MHAUS 2023 sequence: STOP triggers, dantrolene 2.5 mg/kg, treat hyperkalemia + acidosis + dysrhythmia + myoglobinuria
Call 911 or go to the nearest emergency room right away if you have:
Referral to MH Diagnostic Center (CHCT / IVCT or RYR1/CACNA1S sequencing); MedicAlert bracelet; family counseling; future anesthetic plan (trigger-free TIVA); MHAUS registry case report (MHAUS 2023, Riazi 2018)
Guideline: MHAUS (Malignant Hyperthermia Association of the United States) Recommendations for Diagnosis and Treatment of Malignant Hyperthermia 2023 + Larach Clinical Grading Scale (Anesth Analg 2010) + Riazi RYR1 post-genomics review (Anesthesiology 2018)