Different anesthetic techniques have been suggested for craniotomy with intraoperative awakening. We describe an asleep-awake-asleep technique with propofol and remifentanil infusions, with pharmacokinetic simulation to predict the effect-site concentrations and to modulate the infusion rates of both drugs, and bispectral index (BIS) monitoring. Five critical moments were defined: first loss of consciousness (LOC 1 ), first recovery of consciousness (ROC 1 ), final of neurologic testing (NT), second loss of consciousness (LOC 2 ), and second recovery of consciousness (ROC 2 ). At LOC 1 , predicted effect-site concentrations of propofol and remifentanil were, respectively, 3.6±1.2 μg/mL and 2.4±0.4 ηg/mL. At ROC 1 , predicted effect-site concentrations of propofol and remifentanil were, respectively, 2.1±0.3 μg/mL and 1.8±0.3 ηg/mL. At NT, predicted effect-site concentrations of propofol and remifentanil were, respectively, 0.9±0.3 μg/mL and 1.8±0.2 ηg/mL. At LOC 2 , predicted effect-site concentrations of propofol and remifentanil were, respectively, 2.1±0.2 μg/mL and 2.5±0.2 ηg/mL. At ROC 2 , predicted effect-site concentrations of propofol and remifentanil were, respectively, 1.2±0.5 μg/mL and 1.4±0.2 ηg/mL (data are mean±SE). A significative correlation was found between BIS and predicted effect-site concentrations of propofol (r 2 =0.547, P<0.001) and remifentanil (r 2 =0.533, P<0.001). Multiple regression analysis between BIS and propofol and remifentanil predicted effect-site concentrations at the different critical steps of the procedure was done and found also significative (r 2 =0.7341, P<0.001).

No abstract

No abstract

No abstract

Background and Goal of Study: Some published data suggested that inflammation and C-Reactive Protein (CRP) plasmatic concentration might be related with cognitive impairment after cardiac surgery 1 . We hypothesized that anesthetic needs for loss of consciousness (LOC) are influenced by a pre-operative inflammatory state. Materials and Methods: We studied 78 patients, 36 female, age between 21 and 81 years old, ASA I-IV, Glasgow Coma Score 14-15, submitted to brain and non-brain surgery. Anesthetic management for induction of general anesthesia was the same: using RugloopII® software, anesthesia started with TCI of remifentanil with an effect-site target concentration of 2.5 ng/ml and a constant infusion of 1% propofol at 200 ml/hr until LOC; for each patient, predicted effect-site concentration of propofol at LOC was registered. Pre-operative plasmatic concentration of CRP was determined, but until LOC anesthesiologists in charge was blind for that value.Quadratic regression was done to correlate pre-operative plasmatic concentration of CRP and predicted effect-site concentration of propofol at LOC; p Ͻ 0.05 was considered significant. Results: Pre-operative plasmatic concentration of CRP and predicted effectsite concentration of propofol at LOC showed an inverse correlation (r ϭ 0,79, p Ͻ 0.01) (Figure 1). Similar correlations were found when patients were divided into brain surgery group(r ϭ 0,64, p Ͻ 0.01) and non-brain surgery group (r ϭ 0,86, p Ͻ 0.01).

No abstract

No abstract

No abstract