[The influence of intermittent hemodialysis (HD) on bispectral index (scale) (BIS) and serum propofol concentration under postoperative intravenous sedation].

We experienced a case of postoperative intravenous sedation with propofol during intermittent hemodialysis (HD), and investigated the correlation between the clinical sedation level based on bispectral index scale (BIS) together with Ramsay score, and the serum concentration of propofol. One adult oral cancer patient (carcinoma of the lower gingiva) with end-stage renal dysfunction needing HD was selected for this study. The day after operation, HD was commenced under intravenous sedation with propofol. Clinical sedation level was assessed using BIS and Ramsay score, and serum propofol concentrations were determined in arterial blood samples. Serum concentrations were measured every 15 times until 51 hours after operation. The initial dose of propofol was set at 3.5 mg x kg(-1) x h(-1) on the basis of clinical symptoms. According to BIS and Ramsay score, sedation level decreased lineally for 1 hour after commencement of HD. In contrast, serum propofol concentration incresed from 1.71 microg x ml(-1) to 2.21 microg x ml(-1). Total serum concentration of propofol was enhanced during HD because of dialytic dehydration, but, according to BIS and Ramsay scores, the possibility was suggested that the fraction of albmin-unbound propofol with pharmacological activities was eliminated or absorbed by membrane during HD.