Comparison of cerebral hemodynamic variables in hemorrhagic stroke using dexmedetomidine–propofol versus dexmedetomidine–midazolam

Introduction

Dexmedetomidine has been described as having a positive cerebral hemodynamic effect by reducing the cerebral blood flow/cerebral metabolic index ratio (CBF/CMI ratio) and improving CFB self-regulation; however, no data are available on how this actually modifies brain metabolism.

Methods

We performed a multicenter, prospective, randomized, active comparator (dexmedetomidine–propofol or dexmedetomidine–midazolam) study. We included consecutive adult patients (>18 years old) admitted to ICUs with hemorrhagic stroke and moderate or severe brain edema (measured directly at surgery or by CT scan) who needed sedation for at least 72 hours after randomization. We excluded patients with mild brain edema, contraindications to the use of sedatives and those who could not have a jugular venous line placed. Randomized groups received sedation using dexmedetomidine + midazolam (Group 1) or dex-medetomidine + propofol (Group 2). We obtained basal measurement of several variables indirectly related to cerebral metabolism (jugular venous O₂ saturation – SvjO₂, jugular arteriovenous O₂ difference – Da-vjO2, cerebral oxygen extraction – CEO2, estimated cerebral metabolic rate – ECMRO2) and repeated these measurements after 72 hours. Statistical analysis was performed using chi-square and proportions for categorical variables, and the median, standard deviation and Student t test for continuous variables. We considered P ≤ 0.05 significant.

Results

Twenty-eight consecutive patients were included (15 male), average age 61.2 ± 8.6 years, presenting with moderate brain edema (5/28, 17.9%) or severe brain edema (23/28, 82.1%). Both randomized groups had 14 patients. We found no difference between groups in SvjO₂ (P = 0.49 basal, P = 0.19 at 72 hours), Da-vjO₂ (P = 0.68 basal, P = 0.67 at 72 hours), CEO₂ (P = 0.49 basal, P = 0.19 at 72 hours), or ECMRO₂ (P = 0.34 basal, P = 0.50 at 72 hours).

Conclusion

No significant differences in the measured brain metabolism variables were found among the two groups. We suggest comparing these two groups versus a placebo group in another study.