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

Use of the Bispectral Index to Predict Recovery of Consciousness in Patients with Spontaneous Intracerebral Hemorrhage After Surgical Hematoma Evacuation: A Prospective Cohort Study

Background

Our study aimed to test the predictive value of the bispectral index (BIS) for the post-operational consciousness recovery in patients undergone hematoma evacuation due to spontaneous intracerebral hemorrhage (ICH).

Material/Methods

In this prospective cohort study, we enrolled adult spontaneous ICH patients after surgical hematoma evacuation who did not recover consciousness on the first postoperative day. After patient enrollment, the BIS was continuously monitored for 12 hours, and the motor response on the Glasgow Coma Scale (GCS-M) was evaluated. The patients were followed up for 30 days and divided into a consciousness recovery group and a nonrecovery group. Receiver operating characteristic curve analysis was performed to investigate the predictive values of the BIS, GCS-M and ICH score on the consciousness recovery. The area under the curve (AUC) and 95% confidence interval (95%CI) were calculated. During the 12-hour monitoring period, the peak BIS value after GCS-M stimulation was used for ROC analysis.

Results

Of the 55 enrolled patients, 19 patients recovered consciousness, and 36 patients did not. The BIS value of the consciousness recovery group was significantly higher than that of the nonrecovery group (P<0.001). For consciousness recovery prediction, the AUC (95%CI) of the BIS values after external stimulation was 0.97 (0.91–1.00), which was superior to the GCS-M (0.75 [0.59–0.91]) and ICH score (0.57 [0.41–0.73]).

Conclusions

Our study demonstrates that BIS might be a potential tool for predicting the consciousness recovery in ICH patients undergone surgical hematoma evacuation.

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.

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.