Article
TCD, CPP, CBF, CMRO2, CMRG for monitoring of the cerebral perfusion. Is there a right parameter?
TCD, CPP, CBF, CMRO2, CMRG zum Monitoring der zerebralen Perfusion. Gibt es den richtigen Parameter?
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Published: | April 23, 2004 |
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Outline
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Objective
Several strategies are described in order to monitor the cerebral perfusion in the ventilated and sedated neurosurgical patient. However treatment concepts based solely on TCD or CPP values are controversially discussed. CBF measurements and the subsequent calculation of metabolic parameters are not always available so that data on the comparison of these parameters are sparse. The aim of the study was to evaluate all the above mentioned parameters in comparison to each other and to the treatment outcome according to the GOS and the developement of a delayed ischemic neurological deficit after aneurysmal subarachnoid hemorrhage.
Methods
Thirty patients were included after SAH. The following measurements were performed TCD, ICP, MAP continously or at least on a daily basis. A jugular bulb catheter was placed and CBF measurements using the Xenon133 technique were perfomed when an increase in flow velocity as measured by the TCD techique was observed or a neurological deterioration occurred. Furthermore, data of the discharge CT scan were recorded and the tretment outcome was evaluated according to the glasgow outcome scale 6 months after the SAH.
Results
Fourteen patients (46%) developed a delayed territorial infarction according to the CT scan. All patients showed a increased flow velocity according to the TCD examination. CPP was above 60mmHg in all patients at the time of CBF measurement. CBF values were ischemic in 12 patients (40%). CMRO2 and CMRG were indicating low metabolism in all patients showing subsequent ischemic lesions in the CT scan. All parameters correlated to outcome after 6 months with an exception of ICP, MAP and CPP. The closest correlation to outcome was observed using the metabolic parameters CMRO2 and CMRG (p<0.001). In the correlation analysis of the parameters CPP did not correlate to TCD, CBF or the metabolic parameters. TCD did not correlate to CBF or metabolic parameters. A threshold of a CPP> 70 mmHg did not correlate to a better outcome after SAH.
Conclusions
Monitoring CBF and calculation of the subsequent metabolic parameters such as CMRO2 and CMRG are superior to TCD and CPP examinations. A CPP or TCD targeted therapy seems limited.