The Correlation between Cerebral Blood Flow Measured by Bedside Xenon-CT and Brain Chemistry Monitored by Microdialysis in the Acute Phase following Subarachnoid Hemorrhage

Abstract

Cerebral microdialysis (MD) may be used in patients suffering from subarachnoid hemorrhage (SAH) to detect focal cerebral ischemia. The cerebral MD catheter is usually placed in the right frontal lobe and monitors the area surrounding the catheter. This generates the concern that a fall in cerebral blood flow (CBF) and ischemic events distant to the catheter may not be detected. We aimed to investigate if there is a difference in the association between the MD parameters and CBF measured around the MD catheter compared to global cortical CBF and to CBF in the vascular territories following SAH in the early acute phase. MD catheter was placed in the right frontal lobe of 30 SAH patients, and interstitial glucose, lactate, pyruvate, glycerol, and lactate/pyruvate ratio were measured hourly. CBF measurements were performed during day 0–3 after SAH. Global cortical CBF correlated strongly with CBF around the microdialysis catheter (CBF-MD) (r = 0.911, p ≤ 0.001). This was also the case for the anterior, middle, and posterior vascular territories in the right hemisphere. A significant negative correlation was seen between lactate and CBF-MD (r = −0.468, p = 0.009). The same relationship was observed between lactate and CBF in anterior vascular territory but not in the middle and posterior vascular territories. In conclusion, global CBF 0–3 days after severe SAH correlated strongly with CBF-MD. High lactate level was associated with low global CBF and low regional CBF in the right anterior vascular territory, when the MD catheter was placed in the right frontal lobe.

Intracranial pressure- and cerebral perfusion pressure threshold-insults in relation to cerebral energy metabolism in aneurysmal subarachnoid hemorrhage

“…Another MD location could have influenced the results, particularly between different vascular territories and in penumbral areas in proximity to an intracerebral hemorrhage [ 16 , 29 ]. An earlier Xenon-CT-CBF and microdialysis study by our group showed that global cortical CBF correlated strongly with CBF around the microdialysis catheter placed in normal-appearing brain [ 21 ]. It has also previously been demonstrated that disturbances in MD-variables (lactate, LPR, and glycerol) were more strongly correlated with clinical outcome when measured in normal-appearing brain rather than in perilesional areas [ 16 ].…”

CBF changes and cerebral energy metabolism during hypervolemia, hemodilution, and hypertension therapy in patients with poor-grade subarachnoid hemorrhage

“…There was, however, a good correlation between global CBF and rCBF in the CMD region, which has also been demonstrated in previous studies. 26…”

Using Cerebral Metabolites to Guide Precision Medicine for Subarachnoid Hemorrhage: Lactate and Pyruvate

“…No other metabolite measured showed a significantly different change between the DCI and no-DCI groups, and they did not see a significant rise in LPR [52]. Another study done by Rostami and colleagues showed an equivalent correlation between low CBF and elevated interstitial lactate in the same vascular area of a patient’s brain during the acute phase (days 0–3) following SAH ( r = 0.911) [53].…”