RESUMEN
Early onset of systemic toxicity of local anesthetics is a common complication in regional anesthesia. However late onset of systemic toxicity is an unfamiliar phenomenon for an anesthesiologist. We present a case of a late onset of systemic toxicity of local anesthestics in a patient who received brachial plexus block for hand surgery. An hour later after the block, he complained of light-headedness and anxiety. Then he was found to be unconsciousness with involuntary movement of his four extremities. Later his speech became slurred and patient became unresponsive. Following which, general anesthesia was induced and the patient recovered his consciousness after surgery with no sequela related to systemic toxicity with local anesthetics. We observe from this report that considering the time for local anesthetics to reach peak plasma concentration, anesthesiologists should monitor and observe their patient for at least an hour from the completion of brachial plexus block.