An 18-year-old man has a seizure during placement of an interscalene brachial plexus block with 2% lidocaine. The anesthetist begins to hyperventilate the patientís lungs with 100% O2 using an anesthesia bag and mask. The rationale for this therapy is to

1. Decrease delivery of lidocaine to the brain
2. Prevent hypoxia
3. Hyperpolarize the nerve membranes
4. Convert of lidocaine to the protonated (ionized) form

Any or all of the answers may be correct.

What do you suspect is the cause of this pt's seizure activity??