1. earliest possible sign: increase in end-tidal pCO2
2. tachycardia (early) and other arrhythmias
3. with progression:
a) coagulation disorder (DIC) (bleeding from surgical wound and body orifices)
b) ABG: increasing metabolic acidosis & decreasing pO2
c) pulmonary edema
d) elevated body temperature (may reach ≥ 44 °C (113 °F) at rate of 1 °C/5‑min) (normal patients become hypothermic with general anesthesia)
e) limb muscle rigidity (common, but late)
f) rhabdomyolysis → elevated CPK & myoglobin (late)
4. terminal:
a) hypotension
b) bradycardia
Classical manifestations comprise of tachycardia, increase in expired carbon dioxide levels, muscle rigidity, hyperthermia (>38.8°C) and unexpected acidosis 1).