Central nervous system toxicity from 2ml 1% lidocaine

Background: Small doses of lidocaine into the blood will not cause symptoms of local anesthetic poisoning, unless the patient's individual differences in tolerance to local anesthetics or hypersensitivity to local anesthetics.Because patients with ventricular arrhythmias, peripheral veins or central veins more than 3ml of the loading dose of 2% lidocaine (3mg/kg), the patient will not have symptoms of local anesthetic poisoning.We report a patient with symptoms of local anesthetic poisoning after 2 ml of 1% lidocaine.Case presentation: The patient, 26 years old, 72kg, female, 39 +6 weeks pregnant.During the patient's epidural painless delivery, the epidural catheter was mistakenly inserted into the epidural blood vessel, and only 2ml of 1% lidocaine was given, and the patient developed central nervous system toxicity.Although there is no adverse effect on the mother and fetus in the end, it is an unpleasant process experience for the patient.Conclusions: In this case, there was no blood outflow before the drug injection, and the central nervous system symptoms of local anesthetic.Therefore, in clinical work, the epidural catheter should be withdrawn slowly.The small dose of local anesthetic can directly increase the blood concentration of the skull base through the venous plexus of the spinal canal, and directly contact the brainstem medulla and pons through the blood-brain barrier of the local anesthetic, exceeding the concentration threshold of the central nervous system toxicity of the local anesthetic.