Remifentanil: when and how to use it.

Remifentanil is a new potent mu-agonist with a unique pharmacokinetic profile due to a rapid metabolism by non-specific tissue esterases. As a consequence, remifentanil pharmacokinetics are not modified by severe renal or hepatic dysfunction. During general anaesthesia, any dosage of remifentanil may be used without undue lengthening of emergence times. In cardiac surgery, remifentanil combines the requirement for intra-operative control of stress responses and rapid recovery. The rapid termination of remifentanil action warrants modifications of the current practice concerning early postoperative pain control. Remifentanil may be used as a sedative during monitored analgesia, or as a postoperative analgesic in spontaneously breathing patients, provided bolus doses are avoided. Remifentanil may increase patients' safety by eliminating the risk of delayed respiratory depression, but its correct use requires major changes in our prescribing habits.