Local Anesthetic Toxicity
- CNS: Initially circumoral numbness, dizziness, tinnitus, visual change. Later drowsiness, disorientation, slurred speech, loss of consciousness, convulsions & finally respiratory depression.
- Cardiovascular System: Myocardial depression and vasodilation— hypotension and circulatory collapse.
- Allergic Reactions: Rare (less than 1%) rash, bronchospasm.
Prevention and Treatment of Toxicity
- All Cases: Assure adequate ventilation & administer supplemental Oxygen.
- Seizures: Midazolam.
- Hypotension: Trendelenburg position (head down, legs up), IV fluid bolus (Isotonic Saline or LR), Vasopressor (Dopamine if refractory to above).
- Dysrhythmias: As per ACLS protocol (but do not administer further Lidocaine).
Adjunct to Local Anesthesia for Neuraxial Block
- Adrenalin
- Opioid
- Alpha 2 agonist (clonidine)
- Ketamin
- Neostigmine
- Steroid