Malignant Hyperthermia
ADU-13
Diagnosis
In presence of trigger agent: unexpected, unexplained increase in end-tidal CO2, unexplained tachycardia / tachypnea,masseter muscle spasm after succinylcholine. Hyperthermia is a late sign.
Call for help and a code cart
- Ask: "Who will be the crisis manager?"
- Crisis manager designates checklist reader
Get Malignant Hyperthermia Kit
Call MH Hotline 1.800.644.9737
Assign dedicated person to mix dantrolene
Open IV fluids and consider furosemide
- Goal urine output 1 - 2 mL/kg/hr
Turn off volatile anesthetics and transition to non-triggering anesthetics
- DO NOT delay treatment to change circuit or CO2 absorber
- Insert charcoal filters on inspiratory and expiratory limbs, if available
Turn FiO2 to 100%
Hyperventilate patient at flows of 10 L / min or more
Terminate procedure, if possible
Give dantrolene
Give bicarbonate if metabolic acidosis suspected (maintain pH >7.2)
Treat hyperkalemia, if suspected
Treat dysrhythmias, if present
- Standard antiarrhythmics are acceptable
- DO NOT use calcium channel blockers
Send labs
- Arterial blood gas
- Electrolytes
- Serum creatinine kinase (CK)
- Serum / urine myoglobin
- Coagulation profile
Initiate supportive care
- Cool patient if >39 C:
- Lavage open body cavities
- Gastric lavage with cold water
- Apply ice externally
- Infuse cold saline IV
- STOP cooling when < 38 C
- Place Foley catheter, monitor urine output
- Plan ICU monitoring for 24 hrs
- Cool patient if >39 C:
Drugs
| Dantrolene | 2.5 mg/kg, repeat up to 10 mg/kg until symptoms subside |
|---|---|
| Dantrolene | Rarely, may require up to 30 mg/kg |
| Ryanodex | Reconstitute 250mg vialS with 5 mL sterile water each (shake until orange) |
| Ryanodex | 2.5 mg/kg = 0.05 mL/kg |
| Ryanodex | 70kg patient dose = 3.5 mL (~1 vial) |
| Dantrium or Revonto | Reconstitute 20 mg vials with 60 mL sterile water |
| Dantrium or Revonto | 2.5 mg/kg = 7.5 mL/kg |
| Dantrium or Revonto | 70kg patient dose = 525 mL (~9 vials) |
| Bicarbonate | 1 - 2 mEq/kg slow IV push |
| Furosemide | 40 mg IV |
| Calcium Gluconate / Calcium Chloride | 1-3g IV0.5-1g IV |
| Insulin + Dextrose | 5 - 10 units regular IV50 - 100 mL D50W IV- or -250 - 500 mL D10W IV |
DIFFERENTIAL diagnosis (consider when using high doses of dantrolene without resolution of symptoms)
- Cardiorespiratory
- Hypoventilation
- Sepsis
- Endocrine
- Thyrotoxicosis
- Pheochromocytoma
DIFFERENTIAL diagnosis (consider when using high doses of dantrolene without resolution of symptoms)
- Iatrogenic
- Exogenous CO2 source (e.g. laparoscopy)
- Overwarming
- Neuroleptic Malignant Syndrome
DIFFERENTIAL diagnosis (consider when using high doses of dantrolene without resolution of symptoms)
- Neurologic
- Meningitis
- Intracranial bleed
- Hypoxic encephalopathy
- Traumatic brain injury
DIFFERENTIAL diagnosis (consider when using high doses of dantrolene without resolution of symptoms)
- Toxicology
- Radiologic contrast neurotoxicity
- Anticholinergic syndrome
- Cocaine, amphetamine, salicylate toxicity
- Alcohol withdrawal