The evaluation of intracranial pressure by the carotid eco-color Doppler

Introduction

The evaluation of intracranial pressure (ICP) is useful in several clinical situations. The value of the ICP in centimeters of water is available by a specific and invasive catheter in many hospitals. A simple and noninvasive method for assessing ICP would be of considerable value. This is particularly true with respect to cerebral brain because of the recent interest in the effects of cerebral flow and efforts to understand neurologic dysfunction.

Objective

Our intention in this study is to demonstrate, for the first time, the possibility of the ICP value to be described by the carotid color Doppler method. To our knowledge, no comparison between carotid color Doppler method and ICP available for invasive catheter has been performed until now.

Method

After institutional approval by the local ethical committee on human research, we studied 15 individuals in an intensive care unit by the carotid color Doppler method before transferring them to the surgery center for invasive catheter intracranial introduction.

Results

Their mean age was 40 years, their mean body height was 170 ± 5 cm and mean weight was 68.4 ± 10.2 kg. A 7.5-MHz linear pulsed carotid color Doppler device was used to evaluate the flow, the carotid wave, the pulsatility index and the resistance index. The ICP index of the group was subdivided in normal value between 5-15 cmH₂O; moderate >20 cmH₂O; severe >40 cmH₂O; and critical >60 cmH₂O, as first described by Stene J in 1997.

When the normal value was observed in ICP, the typical normal flow in carotid method was also observed. Moderate elevation in ICP value was represented by higher systolic flow in carotid Doppler than the normal value, while extremes values were observed with higher systolic flow and inversion of diastolic flow in comparison with the baseline. In the critical ICP value, the systolic flow in the carotid method was attenuated and the diastolic flow disappeared.

Conclusion

The carotid color Doppler method is indicated to analyze the elevation of ICP.

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