Research & Innovation in Anesthesia

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VOLUME 6 , ISSUE 1 ( January-June, 2021 ) > List of Articles

Original Article

Monitoring of Depth of Anesthesia Using Entropy Monitor in Off-pump Coronary Artery Bypass Graft Surgery: An Observational Study

Masood Ahmed Chandsha, Naina Dalvi

Keywords : Anesthesia awareness, Depth of anesthesia, Entropy, General anesthesia, Off-pump CABG, Recall

Citation Information : Chandsha MA, Dalvi N. Monitoring of Depth of Anesthesia Using Entropy Monitor in Off-pump Coronary Artery Bypass Graft Surgery: An Observational Study. Res Inno Anesth 2021; 6 (1):11-16.

DOI: 10.5005/jp-journals-10049-0094

License: CC BY-NC 4.0

Published Online: 30-07-2021

Copyright Statement:  Copyright © 2021; The Author(s).


Aims and objectives: To monitor the depth of anesthesia using entropy monitor during off-pump coronary bypass graft surgery and to assess memories or recall of intraoperative awareness using Modified Version of Brice Questionnaire after 48 hours of surgery. Materials and methods: It is a cross-sectional observational study. After approval by the institutional ethics committee, the study was conducted in 100 patients posted for cardiac surgery involving off-pump coronary bypass surgery fulfilling the inclusion criteria. After written valid consent, general anesthesia was given as per the protocol. Entropy indices are calculated and displayed in real-time. The indices were manually recorded at various cardiac events. Controlled mechanical ventilation was continued in the ICU. Tracheal extubation was performed when hemodynamic and respiratory parameters remained stable. All patients were interviewed 48 hours after surgery about any memories or recall of intraoperative awareness using the modified Brice questionnaire. Results: In our study, the hemodynamic parameters like pulse rate, systolic, and diastolic blood pressure were well maintained. Three patients reported awareness during the procedure. One of them had vivid dreams which the patient was not able to recall the nature of the dream and the other two patients who had woken up during the procedure heard some noises during the surgery. None of the patients reported being in pain when awake. Conclusion: An entropy monitor might aid off-pump coronary artery bypass graft surgery (OPCABG) in preventing intraoperative awareness and monitoring the depth of anesthesia. It also aids in reducing anesthetic dosage and hence avoids untoward side effects of anesthesia. Clinical significance: Our study suggested that the incidence of awareness is high during the OPCABG, hence modification in anesthesia technique is needed at present.

  1. Report and findings of the 5th National Audit Project Chapter 14 AAGA in cardiothoracic .
  2. Hug CC. Does opioid anaesthesia exist. Anesthesiology 1990;73:1–4.
  3. Stump DA, Jones TJ, Rorie KD. Neurophysiologic monitoring and outcomes in cardiovascular surgery. J Cardiothorac Vasc Anesth 1999;13:600–613.
  4. Baulig W, Seifert B, Schmid ER, et al. Comparison of spectral entropy and bispectral index electroencephalography in coronary artery bypass graft surgery. J Cardiothorac Vasc Anesth 2009;24:544–549.
  5. Driessen JJ, Harbers JB, Van Emond J, et al. Evaluation of the electroencephalographic bispectral index during fentanyl-midazolam anaesthesia for cardiac surgery. Does it predict haemodynamicresponses during endotracheal intubation and sternotomy? Eur J Anaesthesiol 1999;16:622–627.
  6. Col Ashok Sinha et al. Changes in bispectral index (BIS) values during cardiopulmonary bypass (CPB). Med J Arm Force India 2011;67(1):38–40.
  7. Tiren C. Depth of anaesthesia: a clinical study comparing entropy and BIS in cardiac surgery patients during cardiopulmonary bypass. Eur J Anaesthesiol, Euroanaesthe 2004; Abstracts Programme 2004;21(32):A-140.
  8. Fleischer LH, Glass PSA. Evidence based practice of anesthesiology: can we prevent recall during anaesthesia?. Philadelphia (PA): WB Saunders; 2004. pp 223–pp 237.
  9. Pollard RJ, Coyle JP, Gilber RL, et al. Intraoperative awareness in a regional medical system: a review of 3 years’ data. Anesthesiology 2007;106:269–274.
  10. Muralidhar K, Banakal S, Murthy K, et al. Bispectral index-guided anaesthesia for off-pump coronary artery grafting. Ann Card Anaesth 2008;11(2):105–110.
  11. Rashad S, Shahab N, Safdar A, et al. Awareness during coronary artery bypass grafting surgery. Pakistan Arm Forces Med J 2011;61(4):526–529.
  12. Yun W, Yun Y, Yong-hai S, et al. Investigation and analysis of frequency of awareness in patients undergoing cardiac surgery in Beijing, China. CMJ 2005;118(14):1190–1194.
  13. Sandin RH, Enlund G, Samuelsson P, et al. Awareness during anaesthesia: a prospective case study. Lancet 2000;355:707–711.
  14. Kotur PF. Entropy—a new measure of anaesthetic depth. Indian J Anaesth 2004;48(3):170–171.
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