Teodor Svedung Wettervik, Anders Hånell, Kerstin M Ahlgren, Lars Hillered, Anders Lewén
{"title":"Preliminary Observations of the Loke Microdialysis in an Experimental Pig Model: Are We Ready for Continuous Monitoring of Brain Energy Metabolism?","authors":"Teodor Svedung Wettervik, Anders Hånell, Kerstin M Ahlgren, Lars Hillered, Anders Lewén","doi":"10.1007/s12028-024-02080-5","DOIUrl":null,"url":null,"abstract":"<p><strong>Background: </strong>Brain energy metabolism is often disturbed after acute brain injuries. Current neuromonitoring methods with cerebral microdialysis (CMD) are based on intermittent measurements (1-4 times/h), but such a low frequency could miss transient but important events. The solution may be the recently developed Loke microdialysis (MD), which provides high-frequency data of glucose and lactate. Before clinical implementation, the reliability and stability of Loke remain to be determined in vivo. The purpose of this study was to validate Loke MD in relation to the standard intermittent CMD method.</p><p><strong>Methods: </strong>Four pigs aged 2-3 months were included. They received two adjacent CMD catheters, one for standard intermittent assessments and one for continuous (Loke MD) assessments of glucose and lactate. The standard CMD was measured every 15 min. Continuous Loke MD was sampled every 2-3 s and was averaged over corresponding 15-min intervals for the statistical comparisons with standard CMD. Intravenous glucose injections and intracranial hypertension by inflation of an intracranial epidural balloon were performed to induce variations in intracranial pressure, cerebral perfusion pressure, and systemic and cerebral glucose and lactate levels.</p><p><strong>Results: </strong>In a linear mixed-effect model of standard CMD glucose (mM), there was a fixed effect value (± standard error [SE]) at 0.94 ± 0.07 (p < 0.001) for Loke MD glucose (mM), with an intercept at - 0.19 ± 0.15 (p = 0.20). The model showed a conditional R<sup>2</sup> at 0.81 and a marginal R<sup>2</sup> at 0.72. In a linear mixed-effect model of standard CMD lactate (mM), there was a fixed effect value (± SE) at 0.41 ± 0.16 (p = 0.01) for Loke MD lactate (mM), with an intercept at 0.33 ± 0.21 (p = 0.25). The model showed a conditional R<sup>2</sup> at 0.47 and marginal R<sup>2</sup> at 0.17.</p><p><strong>Conclusions: </strong>The established standard CMD glucose thresholds may be used as for Loke MD with some caution, but this should be avoided for lactate.</p>","PeriodicalId":19118,"journal":{"name":"Neurocritical Care","volume":" ","pages":"222-231"},"PeriodicalIF":3.1000,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11811243/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Neurocritical Care","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1007/s12028-024-02080-5","RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2024/7/31 0:00:00","PubModel":"Epub","JCR":"Q2","JCRName":"CLINICAL NEUROLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Background: Brain energy metabolism is often disturbed after acute brain injuries. Current neuromonitoring methods with cerebral microdialysis (CMD) are based on intermittent measurements (1-4 times/h), but such a low frequency could miss transient but important events. The solution may be the recently developed Loke microdialysis (MD), which provides high-frequency data of glucose and lactate. Before clinical implementation, the reliability and stability of Loke remain to be determined in vivo. The purpose of this study was to validate Loke MD in relation to the standard intermittent CMD method.
Methods: Four pigs aged 2-3 months were included. They received two adjacent CMD catheters, one for standard intermittent assessments and one for continuous (Loke MD) assessments of glucose and lactate. The standard CMD was measured every 15 min. Continuous Loke MD was sampled every 2-3 s and was averaged over corresponding 15-min intervals for the statistical comparisons with standard CMD. Intravenous glucose injections and intracranial hypertension by inflation of an intracranial epidural balloon were performed to induce variations in intracranial pressure, cerebral perfusion pressure, and systemic and cerebral glucose and lactate levels.
Results: In a linear mixed-effect model of standard CMD glucose (mM), there was a fixed effect value (± standard error [SE]) at 0.94 ± 0.07 (p < 0.001) for Loke MD glucose (mM), with an intercept at - 0.19 ± 0.15 (p = 0.20). The model showed a conditional R2 at 0.81 and a marginal R2 at 0.72. In a linear mixed-effect model of standard CMD lactate (mM), there was a fixed effect value (± SE) at 0.41 ± 0.16 (p = 0.01) for Loke MD lactate (mM), with an intercept at 0.33 ± 0.21 (p = 0.25). The model showed a conditional R2 at 0.47 and marginal R2 at 0.17.
Conclusions: The established standard CMD glucose thresholds may be used as for Loke MD with some caution, but this should be avoided for lactate.
期刊介绍：
Neurocritical Care is a peer reviewed scientific publication whose major goal is to disseminate new knowledge on all aspects of acute neurological care. It is directed towards neurosurgeons, neuro-intensivists, neurologists, anesthesiologists, emergency physicians, and critical care nurses treating patients with urgent neurologic disorders. These are conditions that may potentially evolve rapidly and could need immediate medical or surgical intervention. Neurocritical Care provides a comprehensive overview of current developments in intensive care neurology, neurosurgery and neuroanesthesia and includes information about new therapeutic avenues and technological innovations. Neurocritical Care is the official journal of the Neurocritical Care Society.
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