RESUMEN
BACKGROUND: The bispectral index (BIS) is a value derived from an electroencephalograph (EEG); it is correlated with depth of sedation and loss of consciousness. Therefore, it has been considered that its control on sedation depth could influence cost saving in drugs as well as decreased anesthesia costs. METHODS: A total of 175 patients were studied. One hundred patients were given intravenous (i.v.) anesthesia, 50 were observed with a BIS monitor, and the remainder went into the control group. Seventy five patients were given balanced general anesthesia: fifty were observed with BIS monitor, while the remainder functioned as the control group. Drug consumption per patient was measured a to maintain BIS value between 60 and 40, and the cost was calculated. RESULTS: Average drug costs for anesthesia were greater in BIS-controlled groups. Anesthesia cost/h was lower in prolonged procedures (>4 h). The bispectral Index as a sedation monitor during anesthesia is an excellent tool, although it did not show a real economic advantage, and we considered that it world only be feasible during long-term procedures.