Open AccessMonitoring of cerebral oxygenation and local field potential with a variation of isoflurane concentration in a rat model
Author(s) -
Dohoon Choi,
Teo Jeon Shin,
Seonghyun Kim,
Jayyoung Bae,
Dongrae Cho,
Jungyeob Ham,
Jiyoung Park,
Hyoung-Ihl Kim,
Seongwook Jeong,
Boreom Lee,
Jae Gwan Kim
Publication year - 2016
Publication title -
biomedical optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.362
H-Index - 86
ISSN - 2156-7085
DOI - 10.1364/boe.7.004114
Subject(s) - isoflurane , anesthetic , anesthesia , oxygenation , medicine , local field potential , burst suppression , hemodynamics , biomedical engineering , electroencephalography , biology , neuroscience , psychiatry
We aimed to investigate experimentally how anesthetic levels affect cerebral metabolism measured by near-infrared spectroscopy (NIRS) and to identify a robust marker among NIRS parameters to discriminate various stages of anesthetic depth in rats under isoflurane anesthesia. In order to record the hemodynamic changes and local field potential (LFP) in the brain, fiber-optic cannulae and custom-made microelectrodes were implanted in the frontal cortex of the skull. The NIRS and LFP signals were continuously monitored before, during and after isoflurane anesthesia. As isoflurane concentration is reduced, the level of oxyhemoglobin and total hemoglobin concentrations of the frontal cortex decreased gradually, while deoxyhemoglobin increased. The reflectance ratio between 730nm and 850nm and burst suppression ratio (BSR) correspond similarly with the change of oxyhemoglobin during the variation of isoflurane concentration. These results suggest that NIRS signals in addition to EEG may provide a possibility of developing a new anesthetic depth index.