Human cerebral microcirculation and oxygen saturation during propofol-induced reduction of bispectral index †

Klein, Klaus Ulrich; Fukui, Kimiko; Schramm, Patrick; Stadie, Axel; Fischer, Gerrit; Werner, Christian; Oertel, Joachim; Engelhard, Kristin

doi:10.1093/bja/aer227

Cited by 37 publications

(37 citation statements)

References 37 publications

(33 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The technology is based on the combination of tissue spectrometry and laser Doppler flowmetry and has been described in detail in previous studies [8]. The flat probe (LF-3-023 O2C, O2C; LEA Medizintechnik, Giessen, Germany) for combined measurements of relative rcFlow and regional cerebral oxygen saturation (%) transmits white light (500-800 nm, 1 nm resolution, <30 mW) and continuous wave laser light (830 nm, <30 mW) to the tissue, where it is scattered and recollected by the probe.…”

Section: Methodsmentioning

confidence: 99%

“…The flat probe (LF-3-023 O2C, O2C; LEA Medizintechnik, Giessen, Germany) for combined measurements of relative rcFlow and regional cerebral oxygen saturation (%) transmits white light (500-800 nm, 1 nm resolution, <30 mW) and continuous wave laser light (830 nm, <30 mW) to the tissue, where it is scattered and recollected by the probe. The spectral components of the collected light are analysed in comparison with prerecorded deoxygenated and oxygenated haemoglobin, allowing the calculation of tissue oxygen saturation [8]. Calculation of relative blood flow (arbitrary units [AU]) is based on Doppler shift of the continuous Doppler wave laser light, which correlates with flood flow velocitiy and number of moving erythrocytes in tissue [8].…”

Section: Methodsmentioning

confidence: 99%

“…However, there are only few technologies offering the possibility of non-invasive, bedside assessment of CBF in neonates [7]. A new device [Oxygen-to-See (O2C), LEA Medizintechnik, Giessen, Germany] allows non-invasive monitoring of regional tissue oxygen saturation (cSO 2 ) and regional cerebral microcirculation (rcFlow) based on laser Doppler flowmetry and tissue spectrometry [8]. Parameters of O2C measurements have been validated in the pig brain model using coloured microspheres and measurements of venous oxygen saturation [9].…”

Section: Introductionmentioning

confidence: 99%

“…Parameters of O2C measurements have been validated in the pig brain model using coloured microspheres and measurements of venous oxygen saturation [9]. The device has been used in various settings including the noninvasive measurement of renal perfusion and oxygen metabolism to predict postoperative acute kidney injury in neonates and infants following CPB surgery [10] and monitoring of cortical microcirculation during neurosurgical operations [8]. The aim of this study was to analyse whether non-invasive measurement of cerebral perfusion and oxygen consumption is feasible with this new technique and to obtain first data on cerebral oxygen metabolism in neonates and infants after CPB surgery for repair or neonatal palliation of complex congenital heart disease.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Non-invasive assessment of cerebral oxygen metabolism following surgery of congenital heart disease

Neunhoeffer

Sandner

Wiest

et al. 2017

Interactive CardioVascular and Thoracic Surgery

View full text Add to dashboard Cite

OBJECTIVES: Cerebral protection is a major issue in the treatment of infants with complex congenital heart disease. We tested a new device combining tissue spectrometry and laser Doppler flowmetry for non-invasive determination of cerebral oxygen metabolism following cardiac surgery in infants. METHODS:We prospectively measured regional cerebral oxygen saturation cSO 2 and microperfusion (rcFlow) in 43 infants 12-24 h following corrective (n = 30) or palliative surgery (n = 13) of congenital heart defects. For comparison, cerebral blood flow (CBF) was determined by colour duplex sonography of the extracranial cerebral arteries. Cerebral fractional tissue oxygen extraction, approximated cerebral metabolic rate of oxygen (aCMRO 2 ) and cerebral metabolic rate of oxygen (CMRO 2 ) were calculated. CONCLUSIONS: According to our experience, combined photospectrometry and laser Doppler flowmetry enable non-invasive assessment of cerebral oxygen metabolism. The method promises new insights into perioperative cerebral perfusion following palliation or corrective surgery in infancy.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Non-invasive assessment of cerebral oxygen metabolism following surgery of congenital heart disease

Neunhoeffer

Sandner

Wiest

et al. 2017

Interactive CardioVascular and Thoracic Surgery

View full text Add to dashboard Cite

show abstract

“…The oxygen-to-see (O 2 C) technology was used for ultrafast measurement of cerebral hemoglobin oxygen saturation and blood flow to monitor cerebral capillary venous oxygen hemoglobin saturation (So 2 ), cerebral capillary venous blood flow (CBF), and cerebral capillary venous blood flow velocity (CBFV) simultaneously in 2-and 8-mm cerebral depth (O 2 Cdevice; Lea Medizintechnik GmbH, Giessen, Germany) (9)(10)(11). This technology was used to confirm that during the experiment, Pao 2 oscillations were transmitted with the systemic circulation to the brain.…”

Section: Ultrafast Cerebral Hemoglobin Oxygen Saturation and Blood Flmentioning

confidence: 99%

Systemic PaO2 Oscillations Cause Mild Brain Injury in a Pig Model

Klein

Johannes

Brückner

et al. 2016

Critical Care Medicine

View full text Add to dashboard Cite

OBJECTIVE: Systemic PaO2 oscillations occur during cyclic recruitment and derecruitment of atelectasis in acute respiratory failure and might harm brain tissue integrity. DESIGN: Controlled animal study. SETTING: University research laboratory. SUBJECTS: Adult anesthetized pigs. INTER-VENTIONS: Pigs were randomized to a control group (anesthesia and extracorporeal circulation for 20 hr with constant PaO2, n = 10) or an oscillation group (anesthesia and extracorporeal circulation for 20 hr with artificial PaO2 oscillations [3 cycles min¹], n = 10). Five additional animals served as native group (n = 5). MEASUREMENTS AND MAIN RESULTS: Outcome following exposure to artificial PaO2 oscillations compared with constant PaO2 levels was measured using 1) immunohistochemistry, 2) real-time polymerase chain reaction for inflammatory markers, 3) receptor autoradiography, and 4) transcriptome analysis in the hippocampus. Our study shows that PaO2 oscillations are transmitted to brain tissue as detected by novel ultrarapid oxygen sensing technology. PaO2 oscillations cause significant decrease in NISSL-stained neurons (p < 0.05) and induce inflammation (p < 0.05) in the hippocampus and a shift of the balance of hippocampal neurotransmitter receptor densities toward inhibition (p < 0.05). A pathway analysis suggests that cerebral immune and acute-phase response may play a role in mediating PaO2 oscillation-induced brain injury. CONCLUSIONS: Artificial PaO2 oscillations cause mild brain injury mediated by inflammatory pathways. Although artificial PaO2 oscillations and endogenous PaO2 oscillations in lung-diseased patients have different origins, it is likely that they share the same noxious effect on the brain. Therefore, PaO2 oscillations might represent a newly detected pathway potentially contributing to the crosstalk between acute lung and remote brain injury.

show abstract

Neural correlates of successful semantic processing during propofol sedation

et al. 2013

View full text Add to dashboard Cite

Sedation has a graded effect on brain responses to auditory stimuli: perceptual processing persists at sedation levels that attenuate more complex processing. We used fMRI in healthy volunteers sedated with propofol to assess changes in neural responses to spoken stimuli. Volunteers were scanned awake, sedated, and during recovery, while making perceptual or semantic decisions about nonspeech sounds or spoken words respectively. Sedation caused increased error rates and response times, and differentially affected responses to words in the left inferior frontal gyrus (LIFG) and the left inferior temporal gyrus (LITG). Activity in LIFG regions putatively associated with semantic processing, was significantly reduced by sedation despite sedated volunteers continuing to make accurate semantic decisions. Instead, LITG activity was preserved for words greater than nonspeech sounds and may therefore be associated with persistent semantic processing during the deepest levels of sedation. These results suggest functionally distinct contributions of frontal and temporal regions to semantic decision making. These results have implications for functional imaging studies of language, for understanding mechanisms of impaired speech comprehension in postoperative patients with residual levels of anesthetic, and may contribute to the development of frameworks against which EEG based monitors could be calibrated to detect awareness under anesthesia.

show abstract

Human cerebral microcirculation and oxygen saturation during propofol-induced reduction of bispectral index †

Abstract: Findings suggest alteration of the CBF/CMRO₂ ratio by propofol in cortical brain regions; therefore, it might be possible that propofol affects coupling of flow and metabolism in the cerebral microcirculation.

Cited by 37 publications

References 37 publications

Non-invasive assessment of cerebral oxygen metabolism following surgery of congenital heart disease

Non-invasive assessment of cerebral oxygen metabolism following surgery of congenital heart disease

Systemic PaO2 Oscillations Cause Mild Brain Injury in a Pig Model

Neural correlates of successful semantic processing during propofol sedation

Contact Info

Product

Resources

About