Can analysis of the bispectral index prove helpful when monitoring titration of doses of midazolam and ketamine for sedation during paediatric cardiac catheterization.

OBJECTIVE: We investigated the use of the bispectral index for monitoring sedation during cardiac catheterization. The scores for the bispectral index may not reflect correct values in children, but may be helpful during titration of sedatives such as midazolam and ketamine.

METHODS: We conducted a prospective randomized clinical trial in 126 patients scheduled for cardiac catheterization in a teaching hospital. They ranged in age from 4 months to 15 years. In 66 patients, sedation was performed without use of the bispectral index, while the index was used in the other 60 patients. The data collected included heart rate, mean arterial pressure, respiratory rate, saturation of oxygen, amount of sedatives, awakening time and adverse effects. We subdivided the patients into age-related groups for each parameter.

RESULTS: The demographic data were not statistically different. Monitoring with the bispectral index in those aged from 1 to 3 years revealed use of lower doses of midazolam, at 2.09 mg per kg per hr, with standard deviation of 0.36, and similarly lowers doses of ketamine, at 2.07 mg per kg per hr, with standard deviation of 0.22, the values in those not monitored being 2.93, with standard deviation of 0.45, and 2.96 with standard deviation of 0.51 respectively, these difference being statistically significant (p = 0.001 and p = 0.04, respectively). In those aged from 3 to 6 years of age, dosage of midazolam was 2.09, with deviation of 0.36, and of ketamine 1.78, with deviation of 0.27, following use of the bispectral index, compared to 2.89 with deviation of 0.28, and 2.62 with deviation of 0.69 respectively, when the bispectral index was not used, these again being significant differences (p = 0.033 and p = 0.04). The requirements for respiratory support and adverse effects were also significantly lower when using the bispectral index (p less than 0.05). No significant difference was found regarding dosages at the ages of 4 months to 1 year, and 6 to 15 years. The awakening time, however, was shorter with use of the index in those aged from 1 to 6 years.

CONCLUSIONS: When using the bispectral index for monitoring sedation during catheterization in children, we noted decreased need for doses of midazolam and ketamine, a lower need for respiratory support and less adverse effects.