Table 1

Criteria used in the Clinical Grading Scale for Malignant Hyperthermia

Clinical Finding
Manifestation

Respiratory acidosis
End-tidal CO2>55 mmHg; PaCO2>60 mm Hg
Cardiac involvement
Unexplained sinus tachycardia, ventricular tachycardia or ventricular fibrillation
Metabolic acidosis
Base deficit >8 m/Eql
pH<7.25
Muscle rigidity
Generalized rigidity; severe masseter muscle rigidity
Muscle breakdown
Serum creatine kinase concentration >20,000/L units; cola colored urine; excess myoglobin in urine or serum; plasma [K+] >6 mEq/L
Temperature increase
Rapidly increasing temperature; T >38.8°C
Other
Rapid reversal of MH signs with dantrolene. Elevated resting serum creatine kinase concentration.
Family history
Consistent with autosomal dominant inheritance

Rosenberg et al. Orphanet Journal of Rare Diseases 2007 2:21   doi:10.1186/1750-1172-2-21