Criteria Used in the Clinical Grading Scale for Malignant Hyperthermia From Larach et al [1994], Rosenberg et al [2015] Questions Manifestation Clinical Finding (Maximum Score) Choose 1 Manifestation End-tidal CO2 >55 mm Hg, PaCO2 >60 mm Hg Clinical Finding Respiratory acidosis (15) Yes No 2 Manifestation Unexplained sinus tachycardia, ventricular tachycardia, or ventricular fibrillation Clinical Finding Cardiac involvement (3) Yes No 3 Manifestation Base deficit >8 mEq/L, pH<7.25 Clinical Finding Metabolic acidosis (10) Yes No 4 Manifestation Generalized rigidity, severe masseter muscle rigidity Clinical Finding Muscle rigidity (15) Yes No 5 Manifestation Serum creatine kinase concentration >20,000/L units, cola-colored urine, excess myoglobin in urine or serum, plasma [K+] >6 mEq/L Clinical Finding Muscle breakdown (15) Yes No 6 Manifestation Rapidly increasing temperature, T >38.8° C Clinical Finding Temperature increase (15) Yes No 7 Manifestation Rapid reversal of MH signs with dantrolene (score=5) Clinical Finding Other Yes No Manifestation Elevated resting serum creatine kinase concentration (score=10) Clinical Finding Other Yes No 8 Manifestation Consistent with autosomal dominant inheritance Clinical Finding Family history (15) Yes No Continue