Background and Goal of Study: IoC monitor is a recently introduced anesthesic depth monitor which uses the information of EEG spectrum. The aim of this study was to validate IoC levels, as a measure of sedation depth, by comparing it with RASS scale during inhalatory sedation with sevofluorane via the AnaConDa® device after cardiac by-pass surgery.
Materials and Methods: Patients studied (n=14) were collected after cardiac by-pass surgery. They were inhalatory sedated with sevofluorane using the AnaConDa device. The average expired sevofluorane concentration (ETsevo) during the course of the study was 0,5%, according to the weight and minute ventilation of the patient1.
During the sedation, IoC monitoring and RASS were simultaneously registrated each 7,5 minutes until extubation criteria were achieved (spontaneous breathing with T-Tube or support pressure modality ≤ 8 cmH2O, PAFI ≥ 200 with PEEP ≤ 5, PCO2 35-45 mmHg, pH > 7,30, normothermia, hemodynamic stability, haemoglobin > 8 gr/dl, Richmond 0 - (-1)).
We considered deeply sedation RASS values under -3, correctly sedated RASS values between -3 and 0 and awake RASS values over 0. IoC values were considered correctly sedated between 60 and 80.
Pearson's correlation coefficient (r) and prediction probability (Pk) were calculated.
Results: We analyzed a total of 252 determinations. 3 cases were excluded of the study because ETSevo was over 1%. Pearson's correlation coefficient was 0,64 (p< 0,001). Prediction probability was 0,73.
Distribution of samples and IoC/RASS correlation are shown in the graphic below (IoC values are on the y-axis and RASS categories are on the x-axis).
Conclusions: IoC values obtained can predict correctly RASS values during sevofluorane sedation, using AnaConDa®, for ETSevo 0,5%.
IoC and RASS values as a sedation monitoring are interchangeable.
Belda JF. Anesth Anal 2008;106:1207-1214