The use of bispectral index to monitor unconscious children

Utility of bispectral index in the management of multiple trauma patients

Background:

Bispectral index (BIS) monitoring in multiple trauma patients has become a common practice in monitoring the sedation levels. We aimed to assess the utility of BIS in the trauma intensive care unit (ICU).

Methods:

A prospective observational study was conducted in the trauma ICU at Hamad General Hospital in Qatar between 2011 and 2012. Patients were divided in two groups: Group I (without BIS monitoring) and Group II (with BIS monitoring). The depth of sedation was clinically evaluated with Ramsey Sedation Scale, changes in vital signs and Glasgow Coma Scale (GCS) level. Use of sedatives, analgesics, and muscle relaxants were also recorded. Data were compared using Chi-square and Student t-tests.

Results:

A total of 110 mechanically ventilated trauma patients were enrolled with a mean age of 36 ± 14 years. The rate of head injury was greater in Group I when compared with Group II (94% vs. 81%, P = 0.04). In comparison to Group I, patients in Group II had lower GCS and higher mean Injury Severity Score (ISS) (6.3 ± 2.5 vs. 7.4 ± 2.7 and 25.5 ± 8.5 vs. 21.2 ± 4.7, respectively, P = 0.03). The used midazolam dose was less in Group II in comparison to Group I (5.2 ± 2.3 vs. 6.1 ± 2.1, P = 0.03). Also, fentanyl dose was less in Group II (152 ± 58 vs. 187 ± 59, P = 0.004). The rate of agitation, failure of extubation and tracheostomy in Group II were lower than those in Group I, P = 0.001. The length of stay for patients Group I was longer (14.6 ± 7.1 vs. 10.2 ± 5.9 days) in comparison to group II, P = 0.001.

Conclusion:

Management of multiple trauma patients in the trauma ICU with BIS monitoring was found to be associated with better outcomes. BIS monitoring is a guide for adjusting the dosage of sedative agents. It can also minimize agitation, failure of extubation, and length of stay in ICU.

Bispectral index monitoring correlates with the level of consciousness in brain injured patients

BACKGROUND

In general, measuring the level of consciousness in neurological patients is important. To assess the patient's mental status, the Glasgow Coma Scale (GCS) and the level of consciousness (drowsiness, stupor, and coma) have been used in clinical situations. The aim of the present study was to identify the correlation between bispectral index (BIS) and level of consciousness in brain injured patients.

METHODS

Eighty-nine adult patients of both sexes were included in the study. A blinded observer evaluated the mental status (GCS and level of consciousness) of a patient who is admitted in intensive care unit with brain injury, while an investigator noted the patient's BIS. The BIS was measured using a BIS monitor, Model A-3000 vista™ with Sensor Bis quatro™ (Aspect Medical Systems, Norwood, USA). A Spearman's rank correlation coefficient was used to determine if the level of consciousness correlated with the BIS.

RESULTS

In 89 patients, the BIS was found to be significantly correlated with the level of consciousness (r = 0.723, P < 0.01) and GCS (r = 0.646, P < 0.01). The BIS values increased with an increasing level of consciousness. Mean BIS values of coma, semicoma, stupor and drowsiness were 0.14 ± 0.23, 38.9 ± 18.0, 60.3 ± 14.5, and 73.6 ± 16.5, respectively.

CONCLUSIONS

In the present study, a significant correlation existed between level of consciousness and BIS. These findings suggest that BIS may be used for assessing the level of consciousness in brain injured patients. However, the scatter of BIS values for any level of consciousness limited the worth of BIS in predicting mentality except in coma patients.

Monitoring the anaesthetic depth in children - an update

PURPOSE OF REVIEW

There are several commercially available electroencephalogram-derived devices for monitoring anaesthesia depth. This article reviews all published studies describing their use in children; first assessing studies of performance in measuring anaesthesia depth in observational, physiological studies and then describing relevant outcome studies. There is also a brief discussion of why they might be useful, what physiological problems may arise and what the reader should be wary of in the methodology of these studies. The subject is approached from a clinical perspective.

RECENT FINDINGS

There are several physiological studies suggesting that for older children the bispectral index, entropy, Narcotrend index, cerebral state index and A-line ARX index all change with induction of anaesthesia, and have reasonable correlations with doses of anaesthetic agent. There is consistent evidence that the performances are substantially poorer in infants. Some of these devices have been demonstrated to reduce anaesthesia drug consumption and hasten recovery in older children.

SUMMARY

The bispectral index is the most widely studied, but at this stage there is no evidence to suggest any one device is substantially superior to any other. There may be a role emerging for their use in older children, but their use in infants cannot be supported.

Value of bispectral index monitor in differentiating between moderate and deep Ramsay Sedation Scores in children

BACKGROUND

Pediatric patients who undergo diagnostic radiological imaging studies routinely require moderate or deep sedation to a Ramsay Sedation Score (RSS) of 4 or 5, respectively. The correlation between moderate and deep RSS and bispectral index (BIS) in children has never been validated. This study was designed to determine whether the BIS values correlate with RSS of children sedated for diagnostic imaging studies.

METHODS

After Institutional Review Board approval, data were prospectively collected on all children receiving pentobarbital alone for computed tomography or magnetic resonance imaging. On arrival in the recovery room, any child assigned a Ramsay score of 4 or 5 was subsequently monitored with the BIS. Receiver-operating characteristic (ROC) analysis was used to evaluate the discriminative ability of BIS in differentiating depth of anesthesia.

RESULTS

A total of 86 children over 1 year of age were enrolled. Children with Ramsay 4 (moderate) and Ramsay 5 (deep) sedation scores showed no significant difference in age or pentobarbital dose (mg.kg(-1)). BIS values followed a normal Gaussian-shaped distribution for both Ramsay scores. There was no significant difference in mean BIS values between the Ramsay groups (P = 0.64). There was a wide variation in BIS values (range of 31-90), which demonstrates that the BIS monitor does not correlate with the clinically assigned RSS depth of anesthesia in children. The ROC curve for BIS is equivalent to a line of nondiscrimination.

CONCLUSION

BIS has limited ability to distinguish between moderate and deep Ramsay sedation levels in children who receive pentobarbital sedation for diagnostic imaging studies.

Bispectral index monitoring in confirmation of brain death in children

Although the guidelines for the diagnosis of brain death in children are well established, the diagnosis is still under debate, and further confirmatory tests are required. Performing these confirmatory tests presents some drawbacks, such as high costs, the need for specialized personnel and technology, transportation of patients out of the intensive care unit, and the use of contrast media. Bispectral index monitoring can provide real-time, objective, continuous monitoring of the consciousness level in critically ill children. The aim of this prospective study was to define the role of bispectral index monitoring in the confirmation and diagnosis of brain death. Eight children who had fulfilled the diagnostic criteria of brain death were included in the study. The age of patients ranged from 3 months to 15 years. All patients had electrocerebral silence on their electroencephalographic recordings. After the diagnosis of brain death, at least 2-hour monitoring was performed, and all patients expressed a score of 0, indicating brain death. According to our study, the decrease in bispectral index score to 0 in patients with suspected brain death can support and confirm brain death diagnosis in children and can enable scheduling of expensive tests, such as cerebral angiography, in the appropriate time. Nevertheless, further studies are needed to determine the role of the bispectral index in the diagnosis and confirmation of brain death in children. In this article, we review clinical utility, application time, and interpretation of bispectral index monitoring in confirmation of brain death diagnosis in children.