[High dose L-dopa infusion during general anesthesia for gastrectomy in a patient with parkinsonism]

A 68-year-old man with parkinsonism was scheduled for gastrectomy. Levodopa 1400 mg, droxidopa 300 mg and bromocriptine-mesylate 7.5 mg had been administered orally per day to control the symptom before surgery. On the day before surgery, oral medication was stopped and intravenous infusion of levodopa 100 mg.h-1 was started. Without any premedication but with levodopa infusion, anesthesia was induced with thiopental 175 mg and fentanyl 0.05 mg. Tracheal intubation was facilitated with vecuronium 6 mg and an epidural catheter was inserted. Anesthesia was maintained with O2, N2O and sevoflurane, combined with epidural block using mepivacaine. When blood pressure decreased, phenylephrine but not ephedrine was effective to increase blood pressure. Intravenous infusion of levodopa was continued for 19 days with decreasing doses from 8th postoperative day when injection of levodopa into the intestinal tube was started. On the 53rd day, he left the hospital without any complications. Serum concentrations of levodopa during and after surgery were 50 to 100 times higher than the therapeutic levels. However, he developed no complications, which suggests a wide safety range of levodopa. In conclusion, high dose levodopa infusion was effective in controlling the symptoms of Parkinsonism during general anesthesia.