scholarly journals NIRS monitoring of brain and spinal cord — detection of adverse intraoperative events

2003 ◽  
Vol 17 (2-3) ◽  
pp. 483-490 ◽  
Author(s):  
Andrew J. Macnab ◽  
Roy E. Gagnon ◽  
Faith A. Gagnon ◽  
Jacques G. LeBlanc
Keyword(s):  
Spinal Cord ◽  
Near Infrared ◽  
Circulatory Arrest ◽  
Spinal Column ◽  
Haemoglobin Concentration ◽  
Standard Of Care ◽  
Redox Status ◽  
Spinal Cord Monitoring ◽  
Ischaemic Damage ◽  
Brain Monitoring

Near infrared spectroscopy (NIRS) monitors changes in oxygenated haemoglobin (HbO2), and redox status of cytochromeaa3(cyt) continuously and non-invasively in living tissue. We present examples where clinically relevant changes in HbO2and/or cyt were detected in real time, allowing intervention to avert potentially harmful hypoxic-ischaemic damage to the brain and/or spinal cord.Brain monitoring: In children undergoing surgery on cardiopulmonary bypass, observations include that: atrial fibrillation (cardiac arrhythmia) lowered cerebral HbO2concentration; concealed haemorrhage decreased cerebral HbO2concentration; inadequate level of anaesthetic resulted in spikes of changes in volume with interventions such as suturing; circulatory arrest reduced brain HbO2and cyt redox status; and bypass pump problems compromised cerebral blood flow.Spinal cord monitoring: In the experimental animal, we observed that NIRS detected ischaemic change immediately following aortic compression, spinal column distraction (instrumentation to separate the vertebrae), and hypoxia. In an infant requiring release of a congenitally tethered spinal cord, we observed that traction on the spinal cord of the infant resulted in decreased total haemoglobin concentration.Summary: NIRS brain monitoring probably represents the “standard of care” during cardiac surgery because adverse events can be detected and quantified. Similarly, spinal cord monitoring could reduce ischaemic spinal cord damage in spinal cord surgery and aortic aneurysm repair.

scholarly journals Clinical Brain Monitoring with Time Domain NIRS: A Review and Future Perspectives

2019 ◽  
Vol 9 (8) ◽  
pp. 1612 ◽  
Author(s):  
Frédéric Lange ◽  
Ilias Tachtsidis
Keyword(s):  
Time Domain ◽  
Near Infrared ◽  
Haemoglobin Concentration ◽  
Tissue Oxygen Saturation ◽  
Clinical Environment ◽  
Brain Tissue Oxygenation ◽  
Physiological Information ◽  
Recent Developments ◽  
Neonatal Imaging ◽  
Brain Monitoring

Near-infrared spectroscopy (NIRS) is an optical technique that can measure brain tissue oxygenation and haemodynamics in real-time and at the patient bedside allowing medical doctors to access important physiological information. However, despite this, the use of NIRS in a clinical environment is hindered due to limitations, such as poor reproducibility, lack of depth sensitivity and poor brain-specificity. Time domain NIRS (or TD-NIRS) can resolve these issues and offer detailed information of the optical properties of the tissue, allowing better physiological information to be retrieved. This is achieved at the cost of increased instrument complexity, operation complexity and price. In this review, we focus on brain monitoring clinical applications of TD-NIRS. A total of 52 publications were identified, spanning the fields of neonatal imaging, stroke assessment, traumatic brain injury (TBI) assessment, brain death assessment, psychiatry, peroperative care, neuronal disorders assessment and communication with patient with locked-in syndrome. In all the publications, the advantages of the TD-NIRS measurement to (1) extract absolute values of haemoglobin concentration and tissue oxygen saturation, (2) assess the reduced scattering coefficient, and (3) separate between extra-cerebral and cerebral tissues, are highlighted; and emphasize the utility of TD-NIRS in a clinical context. In the last sections of this review, we explore the recent developments of TD-NIRS, in terms of instrumentation and methodologies that might impact and broaden its use in the hospital.

scholarly journals Patterns of change in cytochrome c oxidase redox status

2004 ◽  
Vol 18 (2) ◽  
pp. 161-166
Author(s):  
Roy E. Gagnon ◽  
Andrew J. Macnab ◽  
Jacques G. LeBlanc
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Near Infrared ◽  
Circulatory Arrest ◽  
Redox Status ◽  
Serum Glucose ◽  
Cellular Level ◽  
Clinical Settings ◽  
Data Sets ◽  
Brain Response

Investigators using mono channel near infrared spectroscopy (NIRS) have reported different patterns of change in cytochrome c oxidase (Cyt) in similar studies of tissue ischaemia. We investigated whether there were distinctive differences in NIRS signals obtained simultaneously from different sampling sites during the same imposed physiological intervention within the same subject.Methods: Subjects were 36, healthy, 10 kg, commercial swine undergoing cardiopulmonary bypass to initiate 3 to 7 periods of 7.5 minutes of circulatory arrest. Each arrest was initiated at one of 81 combinations of high, normal, or low levels of core temperature, haematocrit, pH, and serum glucose. Each combination was repeated twice, yielding 162 NIRS data sets.Results: Six distinct patterns of change of Cyt were found. Typically, brain Cyt quickly became reduced shortly after the start of arrest, muscle Cyt did not start becoming reduced until after 3½ minutes of arrest, and spinal cord Cyt either did not change status or became gradually reduced throughout the period of arrest. The brain response may reflect strong oxygen dependence, while the muscle response may indicate a dependency buffered by myoglobin stores, and the spine response may indicate a low concentration of available Cyt that is too diffuse to be rapidly influenced by changes in oxygen availability.Conclusion: Multi‒channel NIRS is needed for systemic evaluation of respiration at the cellular level in clinical settings. Distinctive Cyt patterns of change occur in different organs at the same time, in response to circulatory arrest.

scholarly journals Inhibition of Glycine Re-Uptake: A Potential Approach for Treating Pain by Augmenting Glycine-Mediated Spinal Neurotransmission and Blunting Central Nociceptive Signaling

Biomolecules ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 864
Author(s):  
Christopher L. Cioffi
Keyword(s):  
Spinal Cord ◽  
Dorsal Horn ◽  
Therapeutic Potential ◽  
Opioid Analgesic ◽  
Critical Role ◽  
Analgesic Efficacy ◽  
Standard Of Care ◽  
Current Standard ◽  
Glycine Transporters ◽  
Pathological Pain

Among the myriad of cellular and molecular processes identified as contributing to pathological pain, disinhibition of spinal cord nociceptive signaling to higher cortical centers plays a critical role. Importantly, evidence suggests that impaired glycinergic neurotransmission develops in the dorsal horn of the spinal cord in inflammatory and neuropathic pain models and is a key maladaptive mechanism causing mechanical hyperalgesia and allodynia. Thus, it has been hypothesized that pharmacological agents capable of augmenting glycinergic tone within the dorsal horn may be able to blunt or block aberrant nociceptor signaling to the brain and serve as a novel class of analgesics for various pathological pain states. Indeed, drugs that enhance dysfunctional glycinergic transmission, and in particular inhibitors of the glycine transporters (GlyT1 and GlyT2), are generating widespread interest as a potential class of novel analgesics. The GlyTs are Na+/Cl−-dependent transporters of the solute carrier 6 (SLC6) family and it has been proposed that the inhibition of them presents a possible mechanism by which to increase spinal extracellular glycine concentrations and enhance GlyR-mediated inhibitory neurotransmission in the dorsal horn. Various inhibitors of both GlyT1 and GlyT2 have demonstrated broad analgesic efficacy in several preclinical models of acute and chronic pain, providing promise for the approach to deliver a first-in-class non-opioid analgesic with a mechanism of action differentiated from current standard of care. This review will highlight the therapeutic potential of GlyT inhibitors as a novel class of analgesics, present recent advances reported for the field, and discuss the key challenges associated with the development of a GlyT inhibitor into a safe and effective agent to treat pain.

Use of near-infrared indocyanine videoangiography and Flow 800 in the resectioning of a spinal cord haemangioblastoma

2013 ◽  
Vol 27 (6) ◽  
pp. 847-849 ◽  
Author(s):  
Nicola Benedetto ◽  
Filippo Aquila ◽  
Riccardo Vannozzi
Keyword(s):  
Spinal Cord ◽  
Near Infrared ◽  
Flow 800

Spinal Cord Monitoring

Spine ◽  
1991 ◽  
Vol 16 (Supplement) ◽  
pp. S365 ◽  
Author(s):  
EDGAR G. DAWSON ◽  
JOHN E. SHERMAN ◽  
LINDA E. A. KANIM ◽  
MARC R. NUWER
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Monitoring
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