Relatively large-dose intraoperative remifentanil increased postoperative pain and morphine consumption. These data suggest that remifentanil causes acute opioid tolerance and hyperalgesia.

Supplementing remifentanil-based anesthesia with small-dose ketamine decreased intraoperative remifentanil use and postoperative morphine consumption. These data demonstrate that N-methyl-D-aspartate antagonists, such as ketamine, can be a useful adjuvant to intraoperative remifentanil.

The addition of BIS to standard monitoring decreases isoflurane consumption. However, we found only a small advantage in using BIS with respect to recovery from isoflurane anaesthesia.

We demonstrated that 0.6 minimal alveolar concentration of nitrous oxide combined with a potent anesthetic and an opioid prevents movement after orotracheal intubation without affecting the bispectral index. This demonstrates that the bispectral index is not a useful neurophysiologic variable to monitor the level of anesthesia when nitrous oxide is added to a general anesthetic regimen using propofol and remifentanil.

No abstract