A rescue benzodiazepine on the chart may follow the event rather than cause it.
The case described an eighteen-year-old who developed convulsions about 210 minutes after an infraclavicular block. Intravenous diazepam was used, and the subsequent course was reported as uneventful. The authors considered late local-anesthetic systemic toxicity despite the long symptom-free interval.
One case cannot determine the incidence of delayed toxicity. The diagnostic inference was clinical; normal later investigations do not establish the earlier local-anesthetic concentration. Stopping convulsions after diazepam does not identify their cause.
For a toxicology timeline, place the block, symptom onset and rescue treatment in sequence. Distinguish suspected poisoning from analytically confirmed poisoning. A postevent diazepam detection must be interpreted with the documented treatment history before drawing conclusions about preevent exposure.
Source: Publication PMC9251806. The case-review applications above are interpretive analysis.
Related reading: Valerian and Clonazepam Delayed Provoked Seizures in Zebrafish.