[The effectiveness of a correlation diagram of the echographic and haemodynamic patterns in the brain]

Transcranial Doppler (TCD) constitutes a valuable method for managing acute/critical neurological patients and it would therefore be interesting to reduce, as far as possible, the complexity involved in interpreting its findings.

The Objective of this study was to design and validate a correlation diagram of the echographic patterns and acute haemodynamic situations in the brain that makes it easier to teach and optimises the effectiveness of TCD as a diagnostic aid.

A diagram that represents the average speed and pulsatility index on a system of coordinates. Five fundamental echographic patterns were identified and the most frequent acute cerebral haemodynamic situations are detailed for each of them. The value of the diagram was tested in resident doctors with varying degrees of knowledge of TCD. In the first phase with no diagram (evaluation A), the interpretation of the TCD and diagnosis of the haemodynamic situation in the brain were evaluated in nine clinical cases. In the second phase, with a diagram (evaluation B), they were asked to draw up new reports on the same cases. We compared the number of times they were right in the two evaluations.

A total of 216 echographic reports were obtained. The mean number of correct answers in evaluation A was 2, interquartile range (0.25 3.75). In evaluation B the number of correct answers rose to 4 (3.25 6.75) (p= 0.005). Using the diagram increased the diagnostic capacity of all the residents, but especially so in those with less training.

Use of the diagram makes it easier for people who are not experts to learn to interpret TCD findings in acute/critical neurological situations.