The effect of adding two target-controlled concentrations (1–3 ng mL−1) of remifentanil on MACBAR of desflurane*

Abstract

A target-controlled concentration of 1 ng mL(-1) remifentanil results in a 57% decrease in the MAC(BAR) of desflurane combined with 60% nitrous oxide. Increasing the target concentration of remifentanil to 3 ng mL(-1) produces a further 26% decrease in the MAC(BAR) values of desflurane.

Effects of maintaining intravenous infusion of remifentanil or propofol on anesthesia and palinesthesia during anesthesia and analepsia

“…Its elimination half-life is 3-5 min (Hughes et al, 1992;Kapila et al, 1995;Soltesz et al, 2001). It has been reported (Soltesz et al, 2001;Albertin et al, 2005Albertin et al, , 2006 that remifentanil, combined with other anesthetics at a target concentration of 1-3 ng/mL in the plasma, can inhibit the sympathetic response in 50% of patients when the skin is incised. A target concentration of 4 ng/mL remifentanil is required for intubation, and the target concentration is maintained at 2-5 ng/mL during surgery.…”

Effect of a target-controlled infusion of remifentanil in combination with desflurane during the "maintenance" phase of general anesthesia

“…Daniel et al reported that fentanyl decreased the MAC BAR (blockade of autonomic response) ETC of desflurane when used with N 2 O [8]. Albertin et al reported on remifentanil used in combination with desflurane and 60% N 2 O and infused remifentanil at target concentrations of 1 ng/ml and 3 ng/ml using TCI at 5 min after the first surgical incision and they found that the MAC BAR ETC was decreased to 2.7% and 2.0%, respectively; this showed significant reducing effects of about 37% and 45%, respectively [6]. When performing anesthesia induction, laryngeal manipulation and endotracheal intubation can cause severe hemodynamic changes, To prevent these changes, at least a 1.5 MAC anesthetic concentration is required [9], and depending on different stimuli, the systolic blood pressure and HR can greatly change [10].…”

Remifentanil and Other Opioids

“…This is probably related to the very rapid onset of effect the drug (Nieuwenhuijs et al 2003;Habib et al 2002;Dimitriou et al 2006;Lecomte et al 2006;Bilgin et al 2006;Chanavaz et al 2005;Locala et al 2005;Pleym et al 2004;Ouattara et al 2004;Godet et al 2004;Heijmans et al 2004;Joo et al 2004;Unlugenc et al 2003;Jellish et al 2003;Manyam et al 2006;Albertin et al 2006;Mustola et al 2005;Albertin et al 2004;Bouillon et al 2004;Kern et al 2004;Drover et al 2004;Mertens et al 2003;Milne et al 2003;Fechner et al 2003;Criado and Gomez e Segura 2003;Bothtner et al 2002).…”

“…Without opioid, the hypnotic concentration required for loss of consciousness is lower than the one to prevent response to noxious stimulations (around 1/3 MAC). It is moderately reduced by low-dose opioids: for example, propofol concentration for loss of consciousness is reduced by 25% in the presence of remifentanil 6 ng/ml (Nieuwenhuijs et al 2003;Manyam et al 2006;Albertin et al 2006;Mustola et al 2005;Albertin et al 2004;Bouillon et al 2004;Kern et al 2004;Drover et al 2004;Mertens et al 2003;Milne et al 2003;Fechner et al 2003;Criado and Gomez e Segura 2003;Bothtner et al 2002). Consequently, at high opioid concentrations the hypnotic needs for loss of consciousness may be higher than those to prevent response to noxious stimuli, and a patient might show no response to surgery and be completely awake, especially if he cannot move to signal his awareness because of neuromuscular blockade.…”