Application Of Transcranial Doppler Ultrasound In Intracranial Pressure Monitoring In Children

Objective: This study explored the clinical value of TCD in estimating ICP by continuous monitoring TCD on children with invasive ICP monitoring.Methods: The children who need brain surgery treatment and accept continuous invasive ICP monitoring were collected from January 2014 to December 2015 in the PICU of Shenzhen Children’s Hospital. This was a prospective observational study. The monitoring of TCD were performed when the ICP changes. The parameters of the middle cerebral artery(MCA) of suffering side and the values of ICP were recorded at the same time with the calculated CPP.The date were divided into four groups depended on ICP: group A(ICP<15mm Hg), group B(15mm Hg<ICP≤20mm Hg), group C(20mm Hg<ICP≤25mm Hg)and group D(ICP>25mm Hg). Date of group B, C and D were compared with that of group A to analysis the tendency of TCD parameters and spectral atlas as ICP increased and the correlation between parameters of TCD and ICP, CPP.Results: 1. The parameters of TCD: When compared group B with group A, there was no statistical differences between Vm, Vs, Vd, PI and RI(P>0.05). When compared group C with group A, Vs had no statistical differences(P>0.05). But Vs had statistical differences(P<0.05)and the difference between Vd、PI、RI was significant(P<0.01).When compared group D with group A,Vs still had no statistical differences(P>0.05. The difference between rest parameters was significant(P<0.01).2. The spectral atlas of TCD :When compared group B with group A, a lower D peak was observed and most S2 peak disappeared. When compared group C with group A, we could observe that the S1 peak became sharper and S2 peak disappeared. A phenomenon of deepened notch before reaching D peak was found in some cases and some D peak disappeared. When compared group D with group A, the S1 peak of group D became more sharper, S2 peak disappeared and most D peak disappeared. When the ICP was sustained more than 30 mm Hg, the typical spectral atlas of single cusp peak, diastolic reverse blood flow or a nail-like spectrum can be observed. These typical spectral atlases usually indicated that brain failure or brain death had happened or would happen soon.3. There was a moderate linear correlation between the values of ICP with Vd, PI and RI.The correlation coefficients were separately-0.429, 0.489, 0.474. There was a weak linear correlation between the values of CCP with Vd, PI and RI. The correlation coefficient were separately 0.230、-0.242、-0.314.4. In predicting ICP≥20mm Hg, PI≥1 has a sensitivity of 80.59%, specificity of 66.67%.Conclusion: 1. When the ICP rose, the parameters and spectral atlas of TCD in same case presented dynamic changes, which could indicate intracranial hypertension, but could not predict the changes of CPP.2. To some extent, the PI threshold of 1 could judge whether the ICP rose.3. We could not deduce the actual value of ICP from TCD parameters in children till now.4. When the ICP sustained more than 30 mm Hg, the typical spectral atlas such as diastolic reverse blood flow or a nail-like spectrum could be observed, which indicate brain failure or brain death.