| Hypercarbia* | Controlled ventilation: |
| ETCO2 >55 mmHg | |
| PaCO2 >60 mmHg | |
| Spontaneous ventilation: | |
| ETCO2 >60 mmHg | |
| PaCO2 >65 mmHg | |
| Muscle rigidity | Generalized muscular rigidity (sustained contracture) during anesthesia with triggering agents |
| Severe masseter muscle spasm shortly following succinylcholine administration that does not abate within 1 minute | |
| Arrhythmias | Tachycardia |
| Ventricular arrhythmias (indicating acute hyperkalemia) | |
| Acidosis | Primarily respiratory acidosis but may include varying degrees of metabolic acidosis |
| Arterial pH <7.25 | |
| Base deficit >8 mEq/L | |
| Hyperthermia | Core temperature >38.8°C |
| Rapid rise in temperature | |
| Rhabdomyolysis | CK >20,000 international units after anesthesia with succinylcholine |
| CK >10,000 international units after anesthesia without succinylcholine | |
| Cola-colored urine in perioperative period | |
| Urine myoglobin >60 mcg/L | |
| Serum myoglobin >170 mcg/L | |
| Serum potassium >6 meq/L (without renal failure) |
