BACKGROUND: The present study assesses the utility of a novel invasive device (O2C-, oxygen-to-see-device) for intraoperative measurement of the cerebral microcirculation. CO2 vasoreactivity during 2 different propofol concentrations was used to investigate changes of capillary venous cerebral blood flow (rvCBF), oxygen saturation (srvO2), and hemoglobin concentration (rvHb) during craniotomy. METHODS:Thirty-four patients were randomly assigned to a low propofol (4 mg/kg/h) versus a high propofol (6 mg/kg/h) group. A fiberoptic probe was applied on the cortex next to the surgical site. Measurements were performed during lower (35 mm Hg) and higher (45 mm Hg) levels of partial pressure of carbon dioxide (paCO2). Arterio-venous difference in oxygen concentration (avDO2) and approximated cerebral metabolic rate of oxygen (aCMRO2) were calculated for each paCO2 state. Linear models were fitted to test changes of end points in response to paCO2 and propofol concentration. RESULTS: In comparison to the lower levels of paCO2, higher levels of paCO2 increased rvCBF (P<0.001), and srvO2 (P=0.002). RvHb remained unchanged during measurements (P=0.325). Calculated avDO2 decreased with increasing paCO2 (P<0.001), whereas aCMRO2 did not change during the study (P=0.999). Propofol concentration had no effect on measured or calculated end points. CONCLUSIONS: Increase of rvCBF by paCO2 indicates a preserved CO2 reactivity independent of propofol anesthesia. The consecutive rise in srvO2 implies enhanced oxygen availability due to vasodilatation. Unchanged rvHb represents constant venous hemoglobin concentration. As expected, calculated avDO2 decreases with increased paCO2, whereas aCMRO2 remains unchanged. Despite the promising technical approach, the technology needs validation and further investigation for usage during neurosurgery.
RCT Entities:
BACKGROUND: The present study assesses the utility of a novel invasive device (O2C-, oxygen-to-see-device) for intraoperative measurement of the cerebral microcirculation. CO2 vasoreactivity during 2 different propofol concentrations was used to investigate changes of capillary venous cerebral blood flow (rvCBF), oxygen saturation (srvO2), and hemoglobin concentration (rvHb) during craniotomy. METHODS: Thirty-four patients were randomly assigned to a low propofol (4 mg/kg/h) versus a high propofol (6 mg/kg/h) group. A fiberoptic probe was applied on the cortex next to the surgical site. Measurements were performed during lower (35 mm Hg) and higher (45 mm Hg) levels of partial pressure of carbon dioxide (paCO2). Arterio-venous difference in oxygen concentration (avDO2) and approximated cerebral metabolic rate of oxygen (aCMRO2) were calculated for each paCO2 state. Linear models were fitted to test changes of end points in response to paCO2 and propofol concentration. RESULTS: In comparison to the lower levels of paCO2, higher levels of paCO2 increased rvCBF (P<0.001), and srvO2 (P=0.002). RvHb remained unchanged during measurements (P=0.325). Calculated avDO2 decreased with increasing paCO2 (P<0.001), whereas aCMRO2 did not change during the study (P=0.999). Propofol concentration had no effect on measured or calculated end points. CONCLUSIONS: Increase of rvCBF by paCO2 indicates a preserved CO2 reactivity independent of propofol anesthesia. The consecutive rise in srvO2 implies enhanced oxygen availability due to vasodilatation. Unchanged rvHb represents constant venous hemoglobin concentration. As expected, calculated avDO2 decreases with increased paCO2, whereas aCMRO2 remains unchanged. Despite the promising technical approach, the technology needs validation and further investigation for usage during neurosurgery.
Authors: Felix Neunhoeffer; Michael Hofbeck; Christian Schlensak; Martin Ulrich Schuhmann; Jörg Michel Journal: Pediatr Cardiol Date: 2018-08-25 Impact factor: 1.655
Authors: Alexander Ziebart; Christian Möllmann; Andreas Garcia-Bardon; Jens Kamuf; Moritz Schäfer; Rainer Thomas; Erik K Hartmann Journal: Scand J Trauma Resusc Emerg Med Date: 2018-02-09 Impact factor: 2.953
Authors: Andreas García-Bardon; Jens Kamuf; Alexander Ziebart; Tanghua Liu; Nadia Krebs; Bastian Dünges; Robert F Kelm; Svenja Morsbach; Kristin Mohr; Axel Heimann; Erik K Hartmann; Serge C Thal Journal: Sci Rep Date: 2021-07-09 Impact factor: 4.379