Assessment of sedation-analgesia by means of poincaré analysis of the electroencephalogram

Abstract

Abstract-Monitoring the levels of sedation-analgesia may be helpful for managing patient stress on minimally invasive medical procedures. Monitors based on EEG analysis and designed to assess general anesthesia cannot distinguish reliably between a light and deep sedation. In this work, the Poincaré plot is used as a nonlinear technique applied to EEG signals in order to characterize the levels of sedation-analgesia, according to observed categorical responses that were evaluated by means of Ramsay Sedation Scale (RSS). To study the effect of high frequencies due to EMG activity, three different frequency ranges (FR1=0.5-110 Hz, FR2=0.5-30 Hz and FR3=30-110 Hz) were considered. Indexes from power spectral analysis and plasma concentration of propofol and remifentanil were also compared with the bispectral index BIS. An adaptive Neurofuzzy Inference System was applied to model the interaction of the best indexes with respect to RSS score for each analysis, and leave-one-out cross validation method was used. The ability of the indexes to describe the level of sedation-analgesia, according with the RSS score, was evaluated using the prediction probability (Pk). The results showed that the ratio SD1/SD2FR3 contains useful information about the sedation level, and SD1FR2 and SD2FR2 had the best performance classifying response to noxious stimuli. Models including parameters from Poincaré plot emerge as a good estimator of sedation-analgesia levels.

Can we use Magnesium for sedation in Intensive Care Unit for critically ill patients; Is it as effective as other sedatives?

“…(≥3 days). [1,8] Since our study protocol was within 48 hours, we did not see any symptom (shivering, sweating, tachycardia, bradycardia, abnormal movements) related to withdrawal of midazolam.…”

“…While sedation prevents patients from having painful ex- [9][10][11][12] Midazolam is the most used benzodiazepine in ICU because of its rapid onset and short duration of action, minimal cardiovascular and respiratory effects which make midazolam a valuable sedative that can be given via continuous intravenous infusion in the ICU. [7,8] But prolonged use of midazolam may cause respiratory depression which prolongs the duration of MV and ICU stay. [7] In the study of Gupta et al, [13] where they used dexmedetomidine and midazolam for mechanically ventilated patients in ICU, they found significantly longer duration of MV time in midazolam group with compared to dexmedetomidine group.…”

“…PIS was categorized as 0-3 (mild), 4-6 (moderate), 7-10 (severe). [8,9] Patient sedation was performed within the ranges of RSS: 2-4; and PIS <4.…”

“…Additionally, the Bispectral Index (BIS) (Aspect A-1050, Aspect Medical Systems, Natick, Massachusetts) was used to monitor the depth of anesthesia using electroencephalography data via a set of electrodes (BIS Sensor, Aspect Medical Systems) attached to the patient's forehead per the manufacturer's instructions. [8] The degree of sedation was measured continuously using BIS monitoring. Patients maintained at BIS levels in the range 60-80, which associated with an adequated sedated state.…”

“…Since it does not affect the respiratory drive, it should not interfere with weaning from mechanical ventilation. [7][8][9] In this prospective randomized study, our primary aim was to evaluate the results and the effectiveness of adding magnesium sulfate as an adjuvant drug to midazolam; to assess the consumption of midazolam in an overall sedation protocol and to determine patient satisfaction with that treatment.…”