CHARACTERISTICS OF LOCAL ANESTHETIC TOXICITY

(I) CNS toxicity:
a) Excitation Phase: tinnitus, confusion, restlesness, perioral numbness or tingling, metallic taste, lightheadness, sense of dread and impending doom.
b) Convulsive Phase: grand-mal clonic-tonic seizure
c) Depression Phase: CNS depression with drowsiness and unconsciousness.
d) Repiratory depression and apnea.

(II) CVS Toxicity:
a) Excitation Phase: - hypertension, tachycardia (with convulsions)

b) Depression Phase:
(i) Negative inotropic effect with decreased blood pressure, cardiac output and stroke volume.
(ii) Peripheral vasodilation with further hypotension.

c) Cardiovascular Collapse