[Agranulocytosis caused by metamizol. Anesthetic attitude].

Agranulocytosis induced by metamizole is uncommon, with a frequency of less than one case per million treatments. We describe such a case in a patient requiring emergency surgery. An 85-year-old man with a history of infantile paralysis with mental retardation and Paget's disease and X-ray signs of the right femur came to the emergency room with a diaphysial fracture. He received 1 g metamizole i.v. every 8 hours for analgesia. Ten hours after admission a routine blood cell count showed a rapid fall in the number of leukocytes; at 24 hours the count was 600 x 10(9)/l. The diagnosis was agranulocytosis induced by metamizole. Postponement of surgery was advisable and treatment with granulocyte colony stimulating factor (GCSF) at a dose of 5 micrograms/kg/day. Agranulocytosis resolved after 3 days of treatment, after which time the bone was set with a straight femoral plate under subarachnoid anesthesia. Two packs of red blood cells were required during the immediate postoperative period. Twelve days after surgery the patient was released. We review the anesthetic approach to agranulocytosis and its treatment.