Effect of inhalation of isoflurane at end-tidal concentrations greater than, equal to, and less than the minimum anesthetic concentration on bispectral index in chickens

Abstract Background: Patients with a history of intraoperative awareness with explicit recall (AWR) are hypothesized to be at higher risk for AWR than the general surgical population. In this study, the authors assessed whether patients with a history of AWR (1) are actually at higher risk for AWR; (2) receive different anesthetic management; and (3) are relatively resistant to the hypnotic actions of volatile anesthetics. Methods: Patients with a history of AWR and matched controls from three randomized clinical trials investigating prevention of AWR were compared for relative risk of AWR. Anesthetic management was compared with the use of the Hotelling’s T2 statistic. A linear mixed model, including previously identified covariates, assessed the effects of a history of AWR on the relationship between end-tidal anesthetic concentration and bispectral index. Results: The incidence of AWR was 1.7% (4 of 241) in patients with a history of AWR and 0.3% (4 of 1,205) in control patients (relative risk = 5.0; 95% CI, 1.3–19.9). Anesthetic management did not differ between cohorts, but there was a significant effect of a history of AWR on the end-tidal anesthetic concentration versus bispectral index relationship. Conclusions: Surgical patients with a history of AWR are five times more likely to experience AWR than similar patients without a history of AWR. Further consideration should be given to modifying perioperative care and postoperative evaluation of patients with a history of AWR.

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The Impact of Bispectral Index Versus End-Tidal Anesthetic Concentration-Guided Anesthesia on Time to Tracheal Extubation in Fast-Track Cardiac Surgery

Anesthesia & Analgesia ◽

10.1213/ane.0b013e31827b117e ◽

2013 ◽

Vol 116 (3) ◽

pp. 541-548 ◽

Cited By ~ 17

Author(s):

Alexander Villafranca ◽

Ian A. Thomson ◽

Hilary P. Grocott ◽

Michael S. Avidan ◽

Sadia Kahn ◽

...

Keyword(s):

Cardiac Surgery ◽

Bispectral Index ◽

Fast Track ◽

Tracheal Extubation ◽

Anesthetic Concentration ◽

End Tidal ◽

The Impact

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Influence of Body Temperature on Bispectral Index-Guided Anesthetic Management in Off-Pump Coronary Artery Bypass Grafting

Journal of Cardiac Critical Care TSS ◽

10.1055/s-0040-1718975 ◽

2020 ◽

Vol 4 (02) ◽

pp. 079-085

Author(s):

Muralidhar Kanchi ◽

Priya Nair ◽

Rudresh Manjunath ◽

Kumar Belani

Keyword(s):

Coronary Artery ◽

Body Temperature ◽

Artery Bypass ◽

Anesthetic Depth ◽

Off Pump ◽

Anesthetic Concentration ◽

The Mean ◽

Anesthetic Requirement ◽

Pump Coronary Artery Bypass ◽

End Tidal

Abstract Background Perioperative hypothermia is not uncommon in surgical patients due to anesthetic-induced inhibition of thermoregulatory mechanisms and exposure of patients to cold environment in the operating rooms. Core temperature reduction up to 35°C is often seen in off-pump coronary artery bypass graft (OP-CABG) surgery. Anesthetic depth can be monitored by using bispectral (BIS) index. The present study was performed to evaluate the influence of mild hypothermia on the anesthetic depth using BIS monitoring and correlation of BIS with end-tidal anesthetic concentration at varying temperatures during OP-CABG. Materials and Methods In a prospective observational study design in a tertiary care teaching hospital, patients who underwent elective OP-CABG under endotracheal general anesthesia, were included in the study. Standard technique of anesthesia was followed. BIS, nasopharyngeal temperature, and end-tidal anesthetic concentration of inhaled isoflurane was recorded every 10 minutes. The BIS was adjusted to between 45 and 50 during surgery. Results There were 40 patients who underwent OP-CABG during the study period. The mean age was 51.2 ± 8.7 years, mean body mass index 29.8 ± 2.2, and mean left ventricular ejection fraction was 55.4 ± 4.2%. Anesthetic requirement as guided by BIS between 45 and 50 correlated linearly with core body temperature (r = 0.999; p < 0.001). The mean decrease in the body temperature at the end of 300 minutes was 2.2°C with a mean decrease in end-tidal anesthetic concentration of 0.29%. The reduction in end-tidal anesthetic concentration per degree decrease in temperature was 0.13%. None of the patients reported intraoperative recall. Conclusion In this study, BIS monitoring was used to guide the delivery concentration of inhaled anesthetic using a targeted range of 45 to 50. BIS monitoring allowed the appropriate reduction of anesthetic dosing requirements in patients undergoing OP-CABG without risk of awareness. There was a significant reduction in anesthetic requirements associated with reduction of core temperature. The routine use of BIS is recommended in OP-CABG to titrate anesthetic requirement during occurrence of hypothermia and facilitate fast-track anesthesia in this patient population.

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Correlation between bispectral index, end-tidal anaesthetic gas concentration and difference in inspired–end-tidal oxygen concentration as measures of anaesthetic depth in paediatric patients posted for short surgical procedures

Indian Journal of Anaesthesia ◽

10.4103/ija.ija_653_18 ◽

2019 ◽

Vol 63 (4) ◽

pp. 277

Author(s):

Nandini Dave ◽

Raylene Dias ◽

Barkha Agrawal ◽

Aarti Baghele

Keyword(s):

Oxygen Concentration ◽

Surgical Procedures ◽

Bispectral Index ◽

Gas Concentration ◽

Paediatric Patients ◽

Anaesthetic Depth ◽

End Tidal

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The Use of Bispectral Index Monitoring Does Not Change Intraoperative Exposure to Volatile Anesthetics in Children

Journal of Clinical Medicine ◽

10.3390/jcm9082437 ◽

2020 ◽

Vol 9 (8) ◽

pp. 2437

Author(s):

Cornelius A. Sullivan ◽

Chinyere Egbuta ◽

Raymond S. Park ◽

Karina Lukovits ◽

David Cavanaugh ◽

...

Keyword(s):

General Anesthesia ◽

Bispectral Index ◽

Volatile Anesthetics ◽

Day Surgery ◽

Primary Objective ◽

Recovery Profile ◽

The Face ◽

End Tidal ◽

Discharge Criteria

The exposure of infants and children to volatile anesthetics, such as sevoflurane, has been a topic of concern with respect to the potential risk for long term neurocognitive effects. The primary objective of this study was to determine whether the perioperative utilization of Bispectral Index (BIS) monitoring alters the sevoflurane delivery and exposure to children. This is a prospective randomized trial of two groups of healthy ambulatory day surgery patients (2 to 12 years). The patients in both groups had the BIS applied soon after the induction of general anesthesia, but only the anesthesiologists in the group randomized to BIS visible were able to see the BIS values. All of the patients received general anesthesia with sevoflurane. This study found no difference in the overall exposure to sevoflurane between both groups (mean end-tidal sevoflurane level of 1.8 in both groups, P = 084). The duration of time in the recovery room, the time to meet discharge criteria, the Pediatric Agitation Emergence Delirium (PAED) scores and the Face, Legs, Activity, Cry, Consolability (FLACC) scores were not statistically different between the groups. The application and utilization of intraoperative BIS monitoring does not alter the sevoflurane administration nor the discharge readiness nor the recovery profile in healthy ambulatory children.

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Sevoflurane-induced Reduction of Hypoxic Drive Is Sex-independent

Anesthesiology ◽

10.1097/00000542-199905000-00011 ◽

1999 ◽

Vol 90 (5) ◽

pp. 1288-1293 ◽

Cited By ~ 12

Author(s):

Elise Sarton ◽

Minke van der Wal ◽

Diederik Nieuwenhuijs ◽

Luc Teppema ◽

James L. Robotham ◽

...

Keyword(s):

Bispectral Index ◽

Low Dose ◽

Ventilatory Response ◽

Carbon Dioxide Tension ◽

Opioid Agonist ◽

Men And Women ◽

Ventilatory Responses ◽

Inhalational Anesthetic ◽

Ventilatory Effects ◽

End Tidal

Background Although the mu-opioid agonist morphine affects ventilatory control in men and women in different ways, no data exist regarding the influence of sex on the ventilatory effects of inhalational anesthetics. The authors compared the effect of sevoflurane on the ventilatory response to isocapnic hypoxia in healthy young men and women. Methods Breath-to-breath ventilatory responses to hypoxic steps (number of hypoxic steps, four-six; duration, 3 min; end-tidal oxygen tension, approximately 50 mmHg; end-tidal carbon dioxide tension clamped at approximately 4 mmHg above resting values) were assessed in nine men and nine women without and with low-dose sevoflurane (end-tidal concentration, 0.25%). The bispectral index of the electroencephalogram was measured concomitantly. Results Sevoflurane reduced the hypoxic ventilatory sensitivity significantly in both sexes (men: control, 0.62 +/- 0.17 vs. sevoflurane, 0.38 +/- 0.19 l x min(-1) x %(-1); women: control, 0.52 +/- 0.30 vs. sevoflurane, 0.34 +/- 0.15 l x min(-1) x %(-1)). Sevoflurane-induced reductions of the hypoxic responses were not different in the men and women. During sevoflurane inhalation, the bispectral index values decreased equally in men and women. Conclusion In contrast to morphine, the influence of a low dose of the inhalational anesthetic sevoflurane on the ventilatory response to hypoxia is independent of sex.

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The effect of increased minute ventilation on the changes of end-tidal isoflurane concentration and bispectral index

European Journal of Anaesthesiology ◽

10.1097/00003643-200100001-00066 ◽

2001 ◽

Vol 18 (Supplement 21) ◽

pp. 18

Author(s):

J. H. Kim ◽

Y. T. Nam ◽

J. O. Kim

Keyword(s):

Bispectral Index ◽

Minute Ventilation ◽

Isoflurane Concentration ◽

End Tidal

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The Dynamic Relationship between End-tidal Sevoflurane and Isoflurane Concentrations and Bispectral Index and Spectral Edge Frequency of the Electroencephalogram

Anesthesiology ◽

10.1097/00000542-199905000-00019 ◽

1999 ◽

Vol 90 (5) ◽

pp. 1345-1353 ◽

Cited By ~ 104

Author(s):

Erik Olofsen ◽

Albert Dahan

Keyword(s):

Bispectral Index ◽

Effect Compartment ◽

Spectral Edge Frequency ◽

Spectral Edge ◽

Emax Model ◽

Dynamic Relationship ◽

Ic50 Values ◽

American Society ◽

End Tidal ◽

Speed Of Onset

Background Inhalational anesthetics produce dose-dependent effects on electroencephalogram-derived parameters, such as 95% spectral edge frequency (SEF) and bispectral index (BIS). The authors analyzed the relationship between end-tidal sevoflurane and isoflurane concentrations (FET) and BIS and SEF and determined the speed of onset and offset of effect (t1/2k(e0)). Methods Twenty-four patients with American Society of Anesthesiologists physical status I or II were randomly assigned to receive anesthesia with sevoflurane or isoflurane. Several transitions between 0.5 and 1.5 minimum alveolar concentration were performed. BIS and SEF data were analyzed with a combination of an effect compartment and an inhibitory sigmoid Emax model, characterized by t1/2k(e0), the concentration at which 50% depression of the electroencephalogram parameters occurred (IC50), and shape parameters. Parameter values estimated are mean +/- SD. Results The model adequately described the FET-BIS relationship. Values for t1/2k(e0), derived from the BIS data, were 3.5 +/- 2.0 and 3.2 +/- 0.7 min for sevoflurane and isoflurane, respectively (NS). Equivalent values derived from SEF were 3.1 +/- 2.4 min (sevoflurane) and 2.3 +/- 1.2 min (isoflurane; NS). Values of t1/2k(e0) derived from the SEF were smaller than those from BIS (P < 0.05). IC50 values derived from the BIS were 1.14 +/- 0.31% (sevoflurane) and 0.60 +/- 0.11% (isoflurane; P < 0.05). Conclusions The speed of onset and offset of anesthetic effect did not differ between isoflurane and sevoflurane; isoflurane was approximately twice as potent as sevoflurane. The greater values of t1/2k(e0) derived from the BIS data compared with those derived from the SEF data may be related to computational and physiologic delays.

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