Preliminary results of data mining in BIS guided Propofol-Remifentanil TCI Anaesthesia

O. Caelen*, E. Engelman#, D. Schmartz#, G. Bontempi*, L. Barvais#

* Machine Learning Group, Computer Science and # Erasmus Hospital Anaesthesia Departments, Université Libre de Bruxelles, Belgium

 

Background and Goal of Study: 

TOOLBOX is a software system which allows saving the archives of BIS guided TCI anaesthesia.  The purpose of the study was to analyse TOOLBOX record files to compare how the anaesthetists titrate the hypnotic and analgesic components of a total intravenous anaesthesia technique according to the phases and types of surgery.

 

Materials and Methods:

The archive files of 34 patients undergoing thyroid surgery and 29 patients undergoing cardiac surgery with CPB, anaesthetised with a BIS  (XP2000, Aspect Medical) guided propofol-remifentanil effect site TCI anaesthesia technique (data recorded every 5 seconds) were imported in a MySQL database and analysed by the R statistical software package.

 

Results and Discussions:

 

Thyroid

before surgery

Thyroid

surgery

Cardiac

before surgery

Cardiac

surgery

Mean Ce Propofol

2.8±0.9

*

2.6±0.5

$

1.3±0.6

*

1.4±0.4

$

Mean Ce Remifenta

3.1±1.6

5.8±1.9

2.6±1.4

5.3±1.7

Mean BIS

40.7±15.2

*

39.3±8.8

$

56.3±14

*

45.8±9

$

%BIS40-60

31.6 *

38.1 $

48.7 *

66.6 $

%BIS < 40

58.6 *

59.2 $

10.5 *

25.3 $

%BIS > 60

9.8 *

2.6 $

40.8 *

8.1 $

Ce = Effect site concentration; % BIS = percentage of time of BIS values within the range; Statistical difference of mean propofol Ce, mean and range of BIS values between thyroid and cardiac surgery before surgery * and during surgery $.

 

Conclusion(s):

When using a propofol-remifentanil effect site TCI anaesthesia technique, the analysis of the anaesthetists’ behaviour shows that they administer the same remifentanil Ce target concentrations during either thyroid or cardiac surgery but targeted higher propofol Ce and tolerated lower mean BIS values in ASA 1-2 patients undergoing thyroid surgery compared to ASA 3 patients undergoing cardiac surgery.