Guidelines for the management of a malignant hyperthermia (MH) crisis
Association of Anaesthetists of Great Britain and Ireland 1998
Consider MH if:
- masseter spasm after suxamethonium
- unexplained, unexpected tachycardia, together with
- unexplained, unexpected increase in end-tidal CO2
1. Withdraw all trigger agents (i.e. all anaesthetic vapours)
2. Install clean anaesthetic breathing system and hyperventilate
3. Abandon surgery if feasible
4. Give dantrolene IV 1 mg/kg initially and repeat prn up to 10 mg/kg
5. Measure arterial blood gases, K+ and creatine phosphokinase (CPK)
6. Measure core temperature
7. Surface cooling, avoiding vasoconstriction
1. Control serious arrhythmias with beta-blockers etc.
2. Control hyperkalaemia and metabolic acidosis
1. Clotting screen to detect disseminated intravascular coagulation
2. Take first voided urine sample for myoglobin estimation
3. Observe urine output for developing renal failure
4. Promote diuresis with fluids/mannitol (20 mg dantrolene contains 3 mg mannitol)
5. Repeat CPK at 24 h.
1. Consider other diagnoses and perform appropriate investigations, e.g. vanillyl mandelic acid, thyroid function tests, white cell count, chest X-ray
2. Consider possibility of myopathy, neurological opinion, EMG
3. Consider possibility of recreational drug ingestion (Ecstasy)
4. Consider possibility of neuroleptic malignant syndrome
5. Counsel patient and/or the family regarding implications of MH
6. Refer patient to MH unit.
[i] Dantrolene in pregnancy: lack of adverse effects on the fetus and newborn infant.
Shime J, Gare D, Andrews J, Britt B.
Am J Obstet Gynecol 1988; 159(4): 831-4
Related examination questions
1. In the treatment of established malignant hyperthermia, the following are recognised as part of the treatment:
(b) EDTA sodium
(c) Sodium bicarbonate
(d) Magnesium sulphate
(e) Glucose and insulin