Anesthesia and analgesia
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Anesthesia and analgesia · Apr 1995
Comparative StudyThe cerebrospinal fluid and plasma pharmacokinetics of sufentanil after thoracic or lumbar epidural administration.
The cerebrospinal fluid (CSF) and plasma pharmacokinetics of sufentanil were studied in 29 adult patients undergoing thoracotomy under general anesthesia. Sufentanil, 75 micrograms, diluted in 10 mL saline, was given preoperatively in either the lumbar or thoracic epidural space to 14 and 15 patients, respectively. Lumbar CSF and plasma were frequently sampled for 10 h and analyzed for sufentanil concentration by radioimmunoassay. ⋯ In the lumbar group, the AUC and Cmax values in CSF were 19 (P < 0.01) and 45 (P < 0.01) times higher than in plasma, and 4.7 (P < 0.01) and 8.2 (P < 0.001) times higher than in CSF in the thoracic group. The decline in sufentanil concentration was more rapid in CSF than plasma; in the lumbar group the CSF/plasma concentration-ratio was eight and five at 6 and 10 h, respectively, after sufentanil administration. This study shows that after epidural administration sufentanil concentrations are higher in CSF than in plasma, and are highly localized within CSF to the site of administration.
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Anesthesia and analgesia · Apr 1995
The pharmacokinetics and neuromuscular effects of rocuronium bromide in patients with liver disease.
To determine the effect of liver disease on the pharmacokinetics of rocuronium, the authors administered 0.6 mg/kg (twice the ED95) to 10 patients with liver disease and compared these results to values in 10 healthy surgical patients. Anesthesia was induced with thiopental and maintained with isoflurane (0.9%-1.1% end-tidal concentration) and nitrous oxide (60%). Venous blood samples were obtained for 6 h after rocuronium injection and plasma concentrations were measured using gas chromatography. ⋯ In turn, elimination half-life was longer in patients with liver disease (111 min) compared to controls (75.4 min). The authors conclude that liver disease alters the pharmacokinetics of rocuronium by increasing its volume of distribution. The longer elimination half-life might result in a longer duration of action of rocuronium in patients with liver disease, particularly after prolonged administration.