MH Dantrolene

CRNA Study Suite · Malignant Hyperthermia Emergency
All Calculators MH
MHAUS Hotline: 1-800-644-9737 (24/7) 1. STOP triggers (volatiles, succ). 2. Hyperventilate 100% O₂ ≥10 L/min. 3. Dantrolene 2.5 mg/kg IV (repeat q5min → max 10 mg/kg). 4. Call for help + MHAUS. 5. Treat hyperkalemia (Ca gluconate 30 mg/kg, insulin+D50, HCO₃). 6. Cool to 38°C. AVOID CCBs with dantrolene — fatal hyperkalemia.
Patient & Formulation
Reference
ParameterValue
Initial dose2.5 mg/kg IV
Repeatq5 min PRN
Max (most cases)10 mg/kg
Post-crisis infusion1 mg/kg q4-6h × 24-48 h
OR stockpile (legacy)36 vials × 20 mg
OR stockpile (Ryanodex)3 vials × 250 mg
(Karlet, 2023, pp. 574-580)
Dosing
Initial Bolus
--
mg IV
Initial Vials
--
vials
Max Dose (10 mg/kg)
--
mg total
Max Total Vials
--
vials
Post-crisis (1 mg/kg)
--
mg q4-6h
Diluent Total (max)
--
mL
Calculation Breakdown
Initial Bolus
2.5 mg/kg IV bolus
--
Initial = -- mg
(Karlet, 2023, p. 574)
Vials Required for Initial Bolus
--
--
Vials = --
Maximum Dose (Initial Responders)
10 mg/kg (may exceed if refractory)
--
Max = -- mg total; requires -- vials
(Karlet, 2023, p. 576)
Post-Crisis Infusion
1 mg/kg IV q4-6h × 24-48 hours (recrudescence rate ~25%)
--
Post-crisis dose = -- mg q4-6h
(Karlet, 2023, pp. 630-631)
Preparation Notes
--
(Karlet, 2023, pp. 578-580)
References

Karlet, M. C. (2023). Musculoskeletal system anatomy, physiology, pathophysiology, and anesthesia management. In S. Elisha, J. S. Heiner, & J. J. Nagelhout (Eds.), Nurse anesthesia (7th ed., pp. 826-850). Elsevier.

How this works

Dantrolene dosing in MH

Dantrolene is the definitive treatment for malignant hyperthermia, blocking calcium release from the sarcoplasmic reticulum through the RYR1 receptor (Douglas, 2019, p. 1126). The initial dose is 2.5 mg/kg IV, repeated every 5 to 10 minutes until tachycardia, hypercarbia, rigidity, and fever resolve, up to a practical maximum of 10 mg/kg, beyond which an alternate diagnosis should be considered (Douglas, 2019, pp. 1133-1134). After the crisis resolves, 1 mg/kg or more continues every 4 to 6 hours for 24 to 48 hours (Douglas, 2019, p. 1133).

Vial math and the hotline

Older Dantrium or Revonto vials hold 20 mg and need 60 mL of sterile water each, so a 70 kg initial dose is about 9 vials; each 250 mg Ryanodex vial reconstitutes in 5 mL, about 1 vial for the same dose (Douglas, 2019, pp. 1133-1134). Early dantrolene cuts MH mortality from about 80% to 4%, and the MH Hotline, 1-800-644-9737, is staffed 24 hours (Douglas, 2019, pp. 1128, 1134).

References

Douglas, M. J. (2019). Malignant hyperthermia. In Chestnut's obstetric anesthesia (6th ed., pp. 1118-1130). Elsevier.