Closed Loop Isoflurane Administration With Bispectral Index in Open Heart Surgery

NCT01069562 | Completed Results

• 1 other identifier: closed loop isoflurane
• Study Type: interventional
• Target: 40
• Locations: 1 country
• Sites: 1

Brief Summary

With the advancement in microprocessor technology and better understanding of pharmacodynamics and pharmacokinetics of anaesthetic agents, computer facilitated closed loop control of anaesthesia using propofol has been shown to be accurate with better performance than manual control. Literature on computer controlled administration of inhalational anaesthetics is few, as it requires the computer to control the dial setting on the vapouriser. The investigators intend to compare the computer controlled closed loop administration of isoflurane by infusing it into the anaesthetic circuit with conventional vaporiser control in elective open heart surgery. 40 patients (ASA (American Society of Anesthesiology) class II-IV; 18- 65 years) undergoing elective cardiac surgery requiring cardiopulmonary bypass (CPB) will be randomly divided into manual or closed loop groups. Propofol will be used for induction of anaesthesia in both groups followed by isoflurane for maintenance. In the manual group, isoflurane will be administered through the Tech 7 vapouriser during pre and post CPB periods to target bispectral index (BIS) of 50. In closed loop group, isoflurane will be administered using infusion of liquid isoflurane into expiratory limb of the closed circuit. This rate of infusion though a conventional syringe pump will be controlled by algorithm termed 'Improvised Anaesthetic Agent Delivery System' (IAADS) to maintain BIS of 50. Patients in both groups will receive 500ml of 100 % oxygen as fresh gas flow. The % of time bispectral index (BIS) is within the 10 of set target BIS of 50 will be the primary outcome measure. The secondary outcome measures will be median performance error (MDPE)(2), median absolute performance error (MDAPE)(2), wobble(2), divergence(2), amount of isoflurane used and hemodynamic parameters will be secondary outcome measures.

Conditions

Open Heart Surgery

Keywords

closed loop control of anesthesia; isoflurane; open heart surgery

Outcome Measures

Primary Outcomes (1)

• Percentage of Time Bispectral Index Remains Within 10 of Target BIS of 50

  The duration of time depth of anesthesia was maintained in the recommended range (as measured by BIS) during the period isoflurane (general anesthetic) was administered to the study population. This value expressed as percentage is the primary outcome. BIS is an objective measure of depth of anesthesia derived from statistical(bispectral) analysis of electroencephalographic waves. BIS ranges from 0 to 100. It decreases monotonically from 100 in the awake state to lower values with sedation and anesthesia.

  8 hours (approximately)

Secondary Outcomes (9)

• Median Performance Error (MDPE)

  8 hours (approximately)

• Median Absolute Performance Error (MDAPE)

  8 hours (approximately)

• Wobble

  8 hours (approximately)

• Percentage of Time Heart Rate Remained Within 25% of Pre-op Baseline

  8 hours (approximately)

• Percentage of Time Mean Arterial Pressure Remained Within 25% of Pre-op Baseline

  8 hours (approximately)

Study Arms (2)

MANUAL

ACTIVE COMPARATOR

In the manual group isoflurane was administered using Tech 7 vapouriser. The dial setting was controlled by the anesthesiologist to achieve and maintain a BIS of 50 during anesthesia.

Other: Conventional control

IAADS group

EXPERIMENTAL

In this group, liquid isoflurane was injected into the circuit using a syringe pump controlled by the IAADS system.The IAADS system has the algorithm to regulate the rate of infusion of isoflurane such that BIS is achieved and maintained at 50 during anesthesia.

Other: Closed loop control

Interventions

Conventional control OTHER

The isoflurane administration to deliver anesthesia will be done conventionally through a Tec 7 vaporiser to maintain the bispectral index at 50.

Also known as: MANUAL CONTROL

MANUAL

Closed loop control OTHER

The isoflurane administration to maintain anesthesia will be by infusion to the anesthesia circuit using syringe pump (injection technique). The rate of delivery of isoflurane will be regulated by computer that uses a control algorithm.

Also known as: AUTOMATED CONTROL

IAADS group

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• American Society of Anesthesiology physical status 2- 4
• elective open heart surgery under general anaesthesia
• requiring Cardio Pulmonary Bypass (CPB)

You may not qualify if:

• body weight ±30% of the ideal body weight
• neurological disorder
• use of any psychoactive medication
• severe stenotic valve lesions
• severe pulmonary artery hypertension
• Tetrology of Fallot repair and other cyanotic heart diseases.

Sponsors & Collaborators

• Post Graduate Institute of Medical Education and Research, Chandigarh: lead

Study Sites (1)

Post graduate institute of medical education and research

Chandigarh, 160012, India

Location

Related Publications (5)

• Locher S, Stadler KS, Boehlen T, Bouillon T, Leibundgut D, Schumacher PM, Wymann R, Zbinden AM. A new closed-loop control system for isoflurane using bispectral index outperforms manual control. Anesthesiology. 2004 Sep;101(3):591-602. doi: 10.1097/00000542-200409000-00007.

  PMID: 15329583 BACKGROUND

• Varvel JR, Donoho DL, Shafer SL. Measuring the predictive performance of computer-controlled infusion pumps. J Pharmacokinet Biopharm. 1992 Feb;20(1):63-94. doi: 10.1007/BF01143186.

  PMID: 1588504 BACKGROUND

• Agarwal J, Puri GD, Mathew PJ. Comparison of closed loop vs. manual administration of propofol using the Bispectral index in cardiac surgery. Acta Anaesthesiol Scand. 2009 Mar;53(3):390-7. doi: 10.1111/j.1399-6576.2008.01884.x.

  PMID: 19243324 BACKGROUND

• Puri GD, Kumar B, Aveek J. Closed-loop anaesthesia delivery system (CLADS) using bispectral index: a performance assessment study. Anaesth Intensive Care. 2007 Jun;35(3):357-62. doi: 10.1177/0310057X0703500306.

  PMID: 17591128 BACKGROUND

• Madhavan JS, Puri GD, Mathew PJ. Closed-loop isoflurane administration with bispectral index in open heart surgery: randomized controlled trial with manual control. Acta Anaesthesiol Taiwan. 2011 Dec;49(4):130-5. doi: 10.1016/j.aat.2011.11.007. Epub 2011 Dec 22.

  PMID: 22221684 DERIVED

Results Point of Contact

• Title: Puri GD
• Organization: Post Graduate Institute of Medical Education and Research

gdpuri007@hotmail.com

91-9914209509

Study Officials

• Puri GD, MBBS MD PhD

  Post Graduate Institute of Medical Education and Research, Chandigarh

  PRINCIPAL INVESTIGATOR

• Sethu Madhavan, MBBS

  Post Graduate Institute of Medical Education and Research, Chandigarh

  PRINCIPAL INVESTIGATOR

• Preethy J Mathew, MBBS, MD

  Post Graduate Institute of Medical Education and Research, Chandigarh

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: Yes

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER

Study Record Dates

• First Submitted: February 1, 2010
• First Posted: February 17, 2010
• Study Start: January 1, 2009
• Primary Completion: June 1, 2010
• Study Completion: June 1, 2010
• Last Updated: February 21, 2011
• Results First Posted: February 21, 2011

Record last verified: 2010-07

Locations

IN (1)