Bispectral index-guided administration of anaesthesia: comparison between remifentanil/propofol and remifentanil/isoflurane:

Benefit of general anesthesia monitored by bispectral index compared with monitoring guided only by clinical parameters. Systematic review and meta-analysis

BACKGROUND

The bispectral index parameter is used to guide the titration of general anesthesia; however, many studies have shown conflicting results regarding the benefits of bispectral index monitoring. The objective of this systematic review with meta-analysis is to evaluate the clinical impact of monitoring with the bispectral index parameter.

METHODS

The search for evidence in scientific information sources was conducted during December 2013 to January 2015, the following primary databases: Medline/PubMed, LILACS, Cochrane, CINAHL, Ovid, SCOPUS and TESES. The criteria for inclusion in the study were randomized controlled trials, comparing general anesthesia monitored, with bispectral index parameter with anesthesia guided solely by clinical parameters, and patients aged over 18 years. The criteria for exclusion were studies involving anesthesia or sedation for diagnostic procedures, and intraoperative wake-up test for surgery of the spine.

RESULTS

The use of monitoring with the bispectral index has shown benefits reducing time to extubation, orientation in time and place, and discharge from both the operating room and post anesthetic care unit. The risk of nausea and vomiting after surgery was reduced by 12% in patients monitored with bispectral index. Occurred a reduction of 3% in the risk of cognitive impairment postoperatively at 3 months postoperatively and 6% reduction in the risk of postoperative delirium in patients monitored with bispectral index. Furthermore, the risk of intraoperative memory has been reduced by 1%.

CONCLUSION

Clinically, anesthesia monitoring with the BIS can be justified because it allows advantages from reducing the recovery time after waking, mainly by reducing the administration of general anesthetics as well as the risk of adverse events.

Intubating conditions and side effects of propofol, remifentanil and sevoflurane compared with propofol, remifentanil and rocuronium: a randomised, prospective, clinical trial

BACKGROUND

Tracheal intubation without muscle relaxants is usually performed with remifentanil and propofol or sevoflurane. Remifentanil 1.0 to 4.0 μg·kg(-1) and propofol 2.0-3.0 mg·kg(-1) or sevoflurane up to 8.0 Vol% provide acceptable, i.e. excellent or good intubating conditions. We hypothesized that sevoflurane 1.0 MAC would provide acceptable intubating conditions when combined with propofol and remifentanil.

METHODS

Eighty-three patients to be intubated were randomised to two groups. The SEVO group received propofol 1.5 mg kg(-1), remifentanil 0.30 μg kg min(-1) and sevoflurane 1.0 MAC; the MR group received the same doses of propofol and remifentanil plus rocuronium 0.45 mg kg(-1). We evaluated intubation and extubation conditions, mean arterial pressure (MAP), heart rate (HR) and bispectral index (BIS). The vocal cords were examined for injury by videolaryngoscopy before and 24 hours after surgery.

RESULTS

ACCEPTABLE INTUBATING CONDITIONS WERE SEEN MORE FREQUENTLY WITH ROCURONIUM THAN WITH SEVOFLURANE: 97% versus 82%; p = 0.03; the subscore for vocal cords was comparable: 100% versus 98%. MAP before intubation decreased significantly compared with the MAP at baseline to the same extent in both groups; ephedrine IV was given in 15 (SEVO) versus 16 (MR) patients; p = 0.93. BIS at tracheal intubation was 27 (13-65) in the SEVO group, 29 (14-62) in the MR group; p = 0.07. Vocal cord injuries (oedema, haematoma) were similar: 4 patients in each group.

CONCLUSIONS

Overall intubating conditions were better when rocuronium was used; the subscore for vocal cords was comparable. The incidence of side effects was the same in the two groups.

TRIAL REGISTRATION

ClinicalTrials.Gov: NCT 01591031.

[Utility of bispectral vs auditory evoked potential monitoring during anesthetic maintenance in combined sevoflurane-regional anesthesia in pediatric patients: comparison with standard practice]

OBJECTIVES

To compare the indices computed by a bispectral (BIS) monitor and an auditory evoked potential (AEP) monitor during maintenance of anesthesia in pediatric patients. A secondary objective was to compare anesthetic consumption and recovery times.

MATERIAL AND METHODS

Patients aged 6 months to 12 years under inhaled anesthesia with sevoflurane were administered a penile or caudal nerve block. BIS and AEP monitoring was then started. The patients were randomized to 3 groups in which the sevoflurane dosage was guided by the BIS index, the A-line ARX index (AAI), or standard procedures (control group). The BIS index, the AAI, the fraction of expired sevoflurane, hemodynamic parameters, and recovery time were the variables recorded for all patients.

RESULTS

Thirty-five patients were enrolled. Significant differences between the 2 monitor groups were observed. The mean (SD) AAI was lower in patients whose dosage was controlled by the BIS index (19 [2]) than in those whose dosage was based on the AEP monitor's reading (22 [4]) (P=.04). According to a Bland and Altman plot, there was good agreement between the BIS index and the AAI except for the highest and, in particular, the lowest values. The volumes of sevoflurane used and the recovery times were similar between groups. There was a positive correlation between the 2 indices (Pearson correlation coefficient, 0.207; P<.001).

CONCLUSIONS

BIS monitoring provided a more stable index than did AEP monitoring and BIS-index guidance achieved a deeper level of hypnosis. There was good correlation between the 2 indices during maintenance of anesthesia. Neither monitor offered advantages over standard procedures with regard to movement, volume of anesthetic consumed, or recovery time.

Sevoflurane-remifentanil versus propofol-remifentanil anesthesia at a similar bispectral level for off-pump coronary artery surgery: no evidence of reduced myocardial ischemia

OBJECTIVE

Sevoflurane could decrease myocardial ischemic injury in patients undergoing off-pump coronary artery bypass surgery. This study was designed to compare postoperative troponin I (cTnI) concentrations after sevoflurane-remifentanil versus propofol-remifentanil anesthesia.

DESIGN

Prospective, randomized single-blind clinical study.

SETTING

University hospital.

PARTICIPANTS

Eighteen patients.

INTERVENTIONS

General anesthesia was conducted with sevoflurane-remifentanil (n = 9) or propofol-remifentanil (n = 9). Administration of sevoflurane and propofol was adjusted to maintain the bispectral index (BIS) between 40 and 60.

MEASUREMENTS AND MAIN RESULTS

Groups were comparable regarding the patients' characteristics. The objective of BIS was maintained in both groups except during the period of coronary artery grafts (p < 0.001) when the BIS number in the propofol group fell below 40 and was significantly lower than in the sevoflurane group. Intraoperative hemodynamic variables were similar between groups. No patient required cardiopulmonary bypass. Need for inotropic and vasoactive support during the first graft was not necessary in the propofol group and occurred in 4 patients in the sevoflurane group (not significant). During the second graft, 2 patients in the propofol group and 3 in the sevoflurane group needed hemodynamic support. Postoperative hemodynamic variables were comparable between groups. Areas under the curve of postoperative increases in cTnI were 27.0 +/- 38.6 and 17.4 +/- 14.6 ng/mL/hour in the sevoflurane and propofol groups, respectively (not significant).

CONCLUSION

This study does not support cardioprotective effects of sevoflurane. The particularly short total cumulative duration of ischemia and the relatively low administered end-tidal sevoflurane concentrations may explain this result.