Qualitative Evaluation of Intracranial Pressure Slopes in Patients Undergoing Brain Death Protocol

Due to the importance of not mistaking when determining the brain death (BD) diagnostic, reliable confirmatory exams should be performed to enhance its security. This study aims to evaluate the intracranial pressure (ICP) pulse morphology behavior in brain-dead patients through a noninvasive monitoring system.

A pilot case-control study was conducted in adults that met the BD national protocol criteria. Quantitative parameters from the ICP waveforms, such as the P2/P1 ratio, time-to-peak (TTP) and pulse amplitude (AMP) were extracted and analyzed comparing BD patients and health subjects.

Fifteen patients were included, and 6172 waveforms were analyzed. ICP waveforms presented substantial differences amidst BD patients when compared to the control group, especially AMP, which had lower values in patients diagnosed with BD (p < 0.0001) and the TTP median (p < 0.00001), but no significance was found for the P2/P1 ratio (p = 0.8). The area under curve for combination of parameters on the BD prediction was 0.77.

In this exploratory study, noninvasive ICP waveforms have shown potential as a screening method in patients with suspected brain death. Future studies should be carried out in a larger population.