Cerebral state index: comparison between pairwise registrations from the left and the right sides of the brain

BIS Targeted Propofol Sparing Effects of Dexmedetomidine Versus Ketamine in Outpatient ERCP: A Prospective Randomised Controlled Trial

BACKGROUND

Endoscopic Retrograde Cholangio Pancreatography (ERCP) is routinely performed under propofol sedation. Adjuvant drugs have improved the quality of propofol sedation while minimizing complications. The aim of the study was to compare the propofol consumption, recovery and hemodynamic profiles of dexmedetomidine versus ketamine against a placebo control with BIS targeted in the sedative range for outpatient ERCP procedures.

MATERIALS AND METHODS

The study comprised of 72 patients undergoing ERCP, who were randomly allocated into one of the 3 groups: Group Dexmedetomidine (n =24) receiving a bolus and infusion of dexmedetomidine (1μg/kg and 0.5μg/kg/hr); Group Ketamine (n = 24) receiving a bolus and infusion of ketamine (0.25mg/kg and 5μg/kg/min) and Group Control (n =24) receiving saline placebo as a bolus and infusion with variable propofol boluses administered in all groups targeting BiSpectral Index between 60-70.

RESULTS

The total propofol consumption was significantly lower in both Dexmedetomidine (162.5 ± 71.7 mg ) and Ketamine groups (158.3 ± 66.89 mg) when compared with Control group (255.83 ± 114.12 mg)(p=0.001) .Time taken (minutes) to achieve Modified Aldrette Score (MAS) >9 and Observer Assessment of Alertness and Sedation (OAAS) score >4 was significantly prolonged in Dexmedetomidine group (MAS 16.6 ± 3.18 and OAAS 16.67 ± 2.82) compared to Ketamine (MAS 10 ± 4.17 and OAAS 8.75 ± 3.68) and Control (MAS 7.5 ± 3.29 and OAAS 6.88 ± 2.47) (p<0.001). Hemodynamic profiles were comparable although patients in dexmedetomidine had a statistically significant lower heart rate (p<0.001) although without clinical significance.

CONCLUSION

Low dose ketamine with background propofol boluses resulted in lesser propofol consumption, with earlier recovery and favourable hemodynamics when compared with Dexmedetomidine and control group in outpatient ERCP.

Agreement of cerebral state index and glasgow coma scale in brain-injured patients

Background:

Variables derived from electroencephalogram like cerebral state index (CSI) have been used to monitor the anesthesia depth during general anesthesia. Observed evidences show such variables have also been used as a detector of brain death or outcome predictor in traumatic brain-injured (TBI) patients.

Objectives:

The current study was designed to determine the correlation between Glasgow coma score (GCS) and CSI among TBI patients.

Patients and Methods:

In 60 brain-injured patients who did not need and receive sedatives, GCS and CSI were daily measured during the first ten days of their hospital stay. Correlation between GCS and CSI was studied using the Pearson's correlation test. The Gamma agreement coefficient was also calculated between the two variables for the first day of hospitalization.

Results:

A significant correlation coefficient of 0.611-0.796 was observed between CSI and GCS in a ten-day period of the study (P < 0.001). Gamma agreement coefficient was 0.79 (P < 0.001) for CSI and GCS for the first day of hospitalization. An increased daily correlation was observed in both CSI and GCS values. However, this increase was less significant in CSI compared with the GCS.

Conclusions:

A statistically significant correlation and agreement was found between GCS and CSI in the brain-injured patients and GCS was also found to be more consistent and reliable compared with CSI.

Processed electroencephalogram response of patients undergoing carotid endarterectomy: a pilot study

BACKGROUND

A risk during carotid endarterectomy (CEA) is cerebral ischemia as a result of clamping of the carotid artery. The Cerebral State Monitor is one of several electroencephalogram monitors that reflects level of consciousness of patients during anesthesia. The monitor reports level of consciousness with the empirical parameter Cerebral State Index (CSI) on a 0-100 scale. In this patient-controlled prospective pilot study, we compared the CSI measured from the surgical and control hemispheres of patients undergoing CEA surgery to determine whether the parameter is affected by presumed changes in cerebral blood flow.

METHODS

Fifteen consenting CEA patients entered this institutionally approved study. We connected a separate Cerebral State Monitor to the left and right sides of the patient's head and recorded CSI intraoperatively. We compared the control-side data with the surgical-side data.

RESULTS

Clamping caused the surgical-side CSI to drop below the control-side CSI. Shunt activation caused the CSI to rise above the control. The greatest difference between the surgical-side CSI and control-side CSI occurred at the completion of the CEA procedure. These observed trends were not statistically significant in this pilot project.

CONCLUSION

Our preliminary results suggest that the CSI, and perhaps other similar indexes, may indicate changes in cerebral blood flow acutely during CEA. Our findings lend promise to a new use for these types of electroencephalogram monitors, which are prevalent in operating rooms today.

Use of cerebral state index to predict long-term unconsciousness in patients after elective craniotomy with delay recovery

Background

The major difficulty in postoperative care in patients after craniotomy is to distinguish the intracranial deficits from the residual effect of general anesthesia. In present study, we used cerebral state index (CSI) monitoring in patients after craniotomy with delayed recovery, and evaluated the prediction probability of CSI for long-term postoperative unconsciousness.

Methods

We enrolled 57 consecutive adult patients admitted to neurosurgical intensive care unit (NICU) after elective craniotomy with delayed recovery. CSI was continuously monitored for 6 hours after admission. Patient's level of consciousness was followed up for 24 hours. According to whether obeyed verbal command, patients were divided into awaken group and non-awaken group. CSI values were compared between the two groups. Prediction probability (P_K) was calculated to determine the probability of CSI in predicting unconsciousness 24 hours after operation.

Results

In awaken group (n = 51), CSI increased significantly after the 2nd NICU admitted hour (P < 0.05). At each time point, CSI values in awaken group were significantly higher than those in non-awaken group (n = 6) (P < 0.05). The values of P_K (SE) for CSI in the first 6 admitted hours ranged from 0.94 (0.06) to 0.99 (0.02).

Conclusions

In patients after craniotomy with delayed recovery, CSI monitoring in early postoperative hours had high prediction probability for long-term unconsciousness. CSI monitoring may be a reliable objective method to predict level of consciousness after elective craniotomy.

Use of cerebral state index monitoring to detect purposeful movement in unsedated brain-injured patients

To test whether the cerebral state index (CSI) can be used as a measurement of the level of consciousness in unsedated brain-injured patients, 21 brain-injured adults were prospectively assessed in 77 separate sessions. After CSI monitoring was set up, the patient's motor responses to verbal and/or painful stimuli were assessed. CSI values were recorded before and after external stimulation. Purposeful movement in response to external stimuli was defined as command obeying and pain localization. Mean maximal CSI values increased significantly after external stimulation: from 71 to 89 and 49 to 62 in patients exhibiting purposeful and non-purposeful movements, respectively. The CSI value showed a high prediction probability (P(K) > 0.8) for detecting purposeful movement to external stimuli, especially after external stimulation (P(K) > 0.9). These results suggest that CSI monitoring might be a valid method for detecting purposeful movement in response to external stimuli in unsedated brain-injured patients.