Transcranial Cerebral Oximetry Research Articles

Cerebral monitoring during carotid endarterectomy using transcranial cerebral oximetry.

This study aimed to evaluate the outcomes of carotid endarterectomies (CEA) performed using transcranial cerebral oximetry as cerebral monitoringMETHODS: This single-center study included patients treated surgically for significant stenosis of the internal carotid artery (ICA) from January 2012 to December 2017RESULTS: Of the 654 patients, 267 were asymptomatic, and 387 were symptomatic. Eversion CEA was performed in 64.8 %, and patched conventional CEA in 35.2 % of all patients. Totally 11.4 % of all patients had a shunt inserted; all patients with the inserted shunt had the conventional pathed CEA. Severe postoperative complications occurred in 1.5 % of asymptomatic patients and 2.6 % of symptomatic patients. The stroke and death ratio in the shunted group was 2.7 %, and in the non-shunted group, 2.1 % (p = 0.7). We found no significant difference in severe postoperative complications between the shunted and non-shunted group. Further, we found the male gender (p = 0.005), coronary artery disease (p = 0.01), and ongoing smoking (p = 0.003) to be significantly associated with neurological symptoms of the ICA stenosis. We also confirmed current tobacco smoking to be significantly associated with the occurrence of postoperative stroke and death (p = 0.005)CONCLUSION: We found transcranial cerebral oximetry to be reliable in the determination of shunt insertion (Tab. 6, Ref. 26).

CAR 4. Transcranial Cerebral Oximetry as Neuromonitoring During Carotid Endarterectomy

Cross-clamp ischemia during carotid endarterectomy can be prevented with carotid shunts in vulnerable patients identified by cerebral monitoring. We evaluated transcranial cerebral oximetry for selective shunt use in 654 patients. We retrospectively collected data on 654 consecutive patients operated on under general anesthesia between 2011 and 2017. Shunts were inserted for a drop of 20% or more in cerebral saturation. Seventy-five patients, 11.4% of our patients, were shunted. The indication for shunt insertion was a decrease in cerebral saturation of >20% after carotid clamping. A total of 11 patients suffered stroke and 3 patients died in the postoperative period; 30-day death/stroke ratio for the whole group was 2.1%. One patient died and one patient suffered stroke in the shunted group in the postoperative period (2.6% 30-day death/stroke ratio). There were 2 deaths and 10 strokes in the group of nonshunted patients (2.1% 30-day death/stroke ratio). There was no significant difference in 30-day death/stroke ratio between the shunted and nonshunted patients. These results suggest that transcranial cerebral oximetry can be used as reliable, noninvasive, and continuous real-time monitoring during carotid endarterectomy.

Combined Stump Pressure and Oximetry for Shunt Use During Carotid Endarterectomy.

Cross-clamp ischemia during carotid endarterectomy can be prevented with carotid bypass shunts in vulnerable patients identified by cerebral monitoring for ischemia. We compared transcranial cerebral oximetry (TCO) with carotid stump pressure measurements for selective shunt use. We prospectively collected data on 300 consecutive patients operated on under general anesthesia between 2009 and 2016. Shunts were inserted for a 10% or greater drop in cerebral saturations and/or a mean stump pressure less than 40 mmHg. Seventy-five patients, 25% of the study population, were shunted. The indication was a combined desaturation and stump pressure in 38 (50% of the shunted group), desaturation alone in 11 patients (15%), and a low stump pressure alone in 26 patients (35%). There were no significant differences in baseline characteristics between those patients who were or were not shunted, except angiographic collateral blood supply, which was more commonly identified in patients who were not shunted. A watershed infarct occurred in just one patient with borderline TCO and stump pressure measurements in whom a shunt was not used. There was poor concordance between TCO and stump pressures, but using both in determining the need for shunt use almost eliminated cross-clamp ischemia in this series of 300 carotid endarterectomy patients.

Effects of Milrinone continuous intravenous infusion on global cerebral oxygenation and cerebral vasospasm after cerebral aneurysm surgical clipping

BackgroundCerebral vasospasm (CVS) is a disabling disease with high morbidity and mortality risk. Milrinone (phosphodiesterase III inhibitor) has inotropic and vasodilator effects, noninvasive transcranial cerebral oximetry (rSO2%) useful in estimating the effect of triple-H therapy preventive measures against CVS.ObjectiveThe objective of the study is to clarify the value of the use of Milrinone continuous IV infusion as a cerebral vasodilator in post-clipping spasm prevention during the period of maximum vasospasm incidence, guided by noninvasive rSO2%.MethodsPost-clipping all patients extubated in the operative room, shifted to Neurosurgical ICU, and fully monitored. Then, in the period from 4th till the 11th day post-clipping, they were divided into two groups 15 patients each: Group 1: control group, given Norepinephrine continuous IV infusion alone in a dose ranges from 0.05 to 0.2 μg/kg/min. Group 2: given Norepinephrine continuous IV infusion 0.05–0.2 μg/kg/min, Plus Milrinone starting with 50 μg/kg bolus dose, followed by IV infusion at a rate of [0.5–0.75 μg/kg/min]. IMAP, ICP and CPP, GCS, Norepinephrine dose, rSO2%, were recorded every 6 h for the next 168 h. Any attack of cerebral vascular spasm recorded as number and % in each group as an incident.ResultsMBP, rSO2%, ICP, CPP, Norepinephrine Infusion dose, and GCS were significantly increased in Group (2) in comparison with Group (1) mostly during the period of the study. CVS occurrence was significantly lower in group (2), i.e., (20%) cases compared to (46.6%) in group (1).ConclusionsMilrinone improved significantly the global cerebral oxygenation and reduced the incidence of cerebral vasospasm during the dangerous period of cerebral spasm after cerebral aneurysm clipping.

Transcranial cerebral oximetry in newborn infants on mechanical ventilation as a method for prevention of hyperoxia and oxidative stress

The aim of this research was the effectiveness of respiratory therapy in infants with respiratory distress syndrome (RDS) who are ventilated by correcting the oxygen status and parameter optimization of ventilation by determining the oxygen saturation in the brain by transcranial cerebral oximetry (TCO).

Clinical and diagnostic value of transcranial cerebral oximetry in the optimization of mechanical ventilation in newborn infants

Treatment of ischemic damage to organs and tissues by mechanical ventilation with a high content of oxygen in the inspired mixture (FiO2) can lead to oxidative stress and reperfusion of tissue alteration, which is particularly characteristic of infants with their characteristic low levels of antioxidant protection. From this perspective, there is optimal mode selection in mechanical ventilation and FiO2 of vital organs and tissue, namely in brain tissue, which was made possible through the use of transcranial cerebral oximetry (TCO).

Incidence of cerebral desaturation events in the ICU following cardiac surgery

We hypothesize that there is a high incidence of cerebral desaturation events (CDE - an absolute decrease in SctO2 to <55% for ≥15 seconds) during the first 6 hours of ICU admission following cardiac surgery. Clinical trials have validated transcranial cerebral oximetry, a non-invasive tool that uses near-infrared spectroscopy to measure cerebral oxygen saturation, as a way to detect cerebral ischemia [1]. Cerebral oximetry is frequently used in the intraoperative setting, but rarely utilized postoperatively [2]. We attempted to identify if CDEs occur in the ICU.

Cerebral oximetry monitoring during transapical aortic valve replacement

Introduction: The transapical aortic valve implantation (TA-AVI) is an established technique for high-risk patients requiring aortic valve replacement. During this procedure rapid ventricular pacing is required to enable precise positioning of the valve. These periods of reduced or suspended cardiac output may cause impaired organ perfusion and in particular hypoxemia of the brain. Transcranial cerebral oximetry (TCO) is a method to detect cerebral hypoxia.

Near infrared technology in neuroscience: past, present and future

Objective: To review past, present and future applications of near-infrared spectroscopy (NIRS) in clinical neuroscience.Methods: The literature and personal experience of the authors were critically reviewed in order to provide a balanced overview of the basic principles, clinical validation, previous experience and current use of NIRS in assessment of cerebral oxygenation in clinical neuroscience.Results: Recent technological advancements in transcranial cerebral oximetry (TCCO) are opening up a new promising avenue in clinical neuroscience. With its non-invasive nature, high reliability and uniqueness of gathered data, NIRS represents a very special modality in the neuroscience intensive care unit, angiography suite and the operating room. The hurdles of using this technology in clinical practice are discussed in detail. In addition, we evaluate some known limitations of NIRS and current controversies around its use. Lastly, several commercially available cerebral oximeters are presented.Conclusion: Despite remarkable developments in the NIRS technology and proven reliability of the cerebral oxygenation monitoring approach, TCCO remains mostly an adjuvant tool for neuroscience applications. Newer NIRS technologies have become a source of quantitative information about brain oxygenation, cerebral blood volume and flow. However, the clinical significance of this new information in the context of clinical neuroscience will need to be determined and further validation studies will need to be performed.

The abbreviated vigilance task and cerebral hemodynamics

Transcranial Doppler sonography (TCD) and transcranial cerebral oximetry (TCCO) measures of cerebral blood flow velocity and oxygenation levels were collected during an abbreviated 12-min vigilance task. Both the TCD and TCCO measures showed higher levels of cerebral vascular activity in the right than in the left cerebral hemisphere; the cerebral laterality of vigilance occurs in an abbreviated task. Although there was a significant decline in performance over time, there was no significant change in the physiological measures over time during the abbreviated vigil. This latter finding does not match the physiological changes detected in long-duration vigils.

Neuromonitoring in Neurological Critical Care

In this article, we review technologies available for direct monitoring of cerebral oxygenation and metabolic status, including jugular venous oxygen saturation, brain tissue oxygen tension, transcranial cerebral oximetry with near-infrared spectroscopy, Positron emission tomography oxidative metabolism, single-photon emission computed tomography/computed tomography perfusion and functional imaging, and cerebral metabolite measurement using microdialysis. We also introduce a novel method of monitoring cerebral perfusion that may substitute for direct monitoring of oxygenation in the future.

An NIRS matrix for detecting and correcting cerebral oxygen desaturation events during surgery and neuroendovascular procedures

Background: Transcranial cerebral oximetry was developed for early detection of cerebral hypoxia to avoid cerebral dysfunctions. However, near infrared spectroscopy (NIRS) data obtained during surgery are subject to intrinsic and extrinsic influences that have to be accounted for when interpreting the recordings.Methods: We developed an NIRS matrix to provide brief information for a specific intervention to correct changes of cerebral oxygen saturation (COS). Selected vital data and the descriptors of cerebrovascular and neurofunctional status were linked to logistic chains.Results: The matrix is horizontally and vertically grouped and contains five descriptors: 1. change of COS; 2. key variable (parameter related to the change of COS); 3. associated parameters (vital data that do not cause COS alterations); 4. interpretation of values or preconditions most probably due to COS changes; and 5. the intervention most likely to normalize the COS or return it to baseline. The descriptors are grouped horizontally to a logistics chain.Conclusion: The modular expandable NIRS matrix we describe has promise for clinical use in surgical, neurointerventional and anaesthesiological contexts.

Multimodal Monitoring in the Neurological Intensive Care Unit

Neurocritical care is a specialty that focuses on the critical care management of patients with catastrophic neurologic diseases. Brain ischemia and hypoxia are often central causes of brain damage in these patients. Until recently, the only methods widely accepted for monitoring in the neurological intensive care unit have been intracranial pressure and cerebral perfusion pressure monitoring. Recent developments in technology have resulted in several new monitoring techniques that can provide the neurointensivist with information, at the cellular level, that can help guide management. The brain requires a continuous blood-borne supply of oxygen and glucose for normal metabolism. Ischemia occurs when supply is insufficient to meet the metabolic demand. Cerebral blood flow can now be directly monitored using laser Doppler or thermal diffusion techniques. Transcranial cerebral oximetry can estimate regional cerebral oxygen saturation, although the reliability is questionable. Jugular bulb oximetry can provide a global assessment of oxygen delivery, and consumption and brain tissue oxygen tension monitoring can provide a focal measurement of cerebral oxygenation. Intracerebral microdialysis can provide information about glucose metabolism and the overall health of the neuron. New monitoring techniques can provide the neurointensivist with crucial information about brain physiology and metabolism. Combining these techniques ("multimodal monitoring") can produce a more accurate overall picture. This approach, along with new computer systems for integrating data at the bedside, may change the way patients with brain injury are monitored and treated in the future.

Transcranial Cerebral Oximetry During Surgical Procedures: A New Matrix Model For Minimization Of Problems Of Interpretation And Intervention In Desaturation Events

Transcranial cerebral oximetry is a method to detect cerebral hypoxia and to avoid cerebral dysfunctions. Regional cerebral oxygen saturation was measured in a 35-year-old female during cerebral aneurysm surgery. For the effective clinical use of near infrared spectroscopy (NIRS) during surgical or endovascular procedures the intrinsic and extrinsic factors which can influence the NIRS data have to be considered. Therefore a NIRS matrix as a short information for the specific management to correct changes of cerebral oxygen saturation (COS) was developed. The aim of development of the NIRS matrix is to support the patient management specifically adapted to the surgical, neurointerventional and anesthesiological context.

Cerebral Vascularity and Performance on an Abbreviated Vigilance Task

Transcranial Doppler sonography (TCD) and transcranial cerebral oximetry (TCCO) measures of blood flow and oxygenization levels in the brain were collected while observers performed an abbreviated 12 min vigilance task designed by Temple et al. (2000) to serve as an analog to more traditional long-duration vigils. Both measures showed higher levels of cerebral vascular activity in the right as compared to the left cerebral hemisphere indicating that the overall level of performance in the abbreviated vigil is right-lateralized, a finding that coincides with the outcome of earlier blood flow studies featuring more traditional long-duration vigils. This parallel provides strong support for Temple et al's (2000) argument that the abbreviated vigil is a valid analog of more traditional long-duration vigilance tasks and implies that laterality in vigilance is a generalized effect in terms of cerebral vascular dynamics that appears in terms of both blood oxygenation and hemovelocity.

Transcranial cerebral oximetry (TCCO) monitoring in neurosurgical critically ill patients

Near-infrared spectroscopy (NIRS) has been used to monitor cerebral oxygenation in various clinical fields. However, its utility has not been demonstrated in more complex situations, such as neurosurgical critically ill patients. The objective of this study was to examine the ability of TCCO to detect cerebrovascular events, such as oligemic hypoxia, relative cerebral hyperemia and vasospasm in neurosurgical critically ill patients with different outcome.

Transcranial cerebral oximetry, transcranial Doppler sonography, and heart rate variability: useful neuromonitoring tools in anaesthesia and intensive care?

Transcranial cerebral oximetry, transcranial Doppler sonography, and heart rate variability: useful neuromonitoring tools in anaesthesia and intensive care?

Correlation of noninvasive cerebral oximetry with cerebral perfusion in the severe head injured patient: a pilot study.

Traumatic brain injury (TBI) is a leading cause of morbidity and mortality in trauma patients. Cerebral perfusion pressure (CPP) directed ICU management is recommended for patients with severe TBI. It, however, requires an invasive device to measure intracranial pressure (ICP). Transcranial cerebral oximetry is a noninvasive method utilizing near-infrared technology to indirectly measure cerebral saturation (StCO2). A prospective observational study was performed at a Level I trauma center. Data were collected hourly for the first 6 days on four patients with severe TBI. Each patient had ICP monitoring and StCO2 (INVOS, Somanetics) assessed from each frontal lobe. CPP directed care was used. Four patients with TBI, with admission GCS scores of 4, 4, 7, and 8, all had subdural hematomas and contusions; three had subarachnoid hemorrhage (SAH); one had an epidural hematoma (the only death; day 6); two had craniotomies. In the first 48 hours when CPP > or = 70, StCO2 was 71 +/- 9, while it was 61 +/- 9 when CPP < 70 (p < 0.0001). This relationship was constant for all study days, with p < 0.0001. Moreover, CPP < 70 correlated with StCO2 with r = 0.8l and r(2) = 0.66. StCO2 > or = 75 was associated with CPP > or = 70 96.4% of the time (95% CL, 94.3-98.5%). StCO2 < 55 was associated with CPP < 70 68.2% of the time (95% CL, 57-79.4%). Also, 13.4% of observations with CPP > or = 70 had StCO2 < 60, suggesting the potential of cerebral ischemia in the face of "normal" CPP. The StCO2 patches were user-friendly and not technically finicky. In this pilot study, StCO2 correlated significantly with CPP. A StCO2 > or = 75 suggests that CPP is adequate, while < 55 suggests an inadequate CPP. Although these results should be confirmed in a larger study, StCO2 may serve as a noninvasive measurement of cerebral perfusion in the patient with a TBI or, at the very least, a sensitive indicator for the need to begin monitoring the ICP.

Transcranial Cerebral Oximetry Related to Transcranial Doppler After Aneurysmal Subarachnoid Haemorrhage

Noninvasive methods for detecting cerebral artery vasospasm, still a serious complication following aneurysmal subarachnoid haemorrhage, are of vital interest. Up-to-date transcranial Doppler ultrasound (TCD) has proved to be sensitive in detecting vasospasm in the middle cerebral artery, but has less accuracy for other cerebral arteries. Transcranial cerebral oximetry (TCCO) is a new non-invasive technique which may increase the reliability for detecting cerebral ischaemia. The purpose of the present study was to evaluate a putative correlation between TCCO and TCD. We examined the two hemispheres in 14 patients with the aim of evaluating a proposed correlation between TCD and TCCO. Analysis of all absolute values (maximum TCD mFV and minimum TCCO saturation, respectively) in all series indicate a correlation between TCCO and TCD, p < 0.01, r = -0.62. All patients with TCD mean flow velocity > 120 cm/s also presented TCCO saturation < 60%. Conversely, all patients with normal TCCO saturation (> or = 63%) presented normal or moderately increased TCD velocities. In clinical neurosurgical practice it is of great interest if a true correlation between TCD and TCCO exists. The present results support the assumption that TCCO may enhance the reliability for detecting cerebral ischaemia after aneurysmal subarachnoid haemorrhage.

Transcranial cerebral oxymetry during carotid endarterectomy: agreement between frontal and lateral probe measurements as compared with an electroencephalogram

Objective: Transcranial cerebral oximetry, which is considered a novel technique, was evaluated during carotid endarterectomy. For practical reasons, the use of a single probe attached to the forehead and overlying the territory of the anterior cerebral artery is recommended. Other monitoring systems (transcranial Doppler, electroencephalograms (EEG)) focus more on the territory of the middle cerebral artery. The aim of this study was to evaluate whether a probe in the frontal area is as representative for monitoring cerebral ischaemia during carotid cross-clamping as a probe in the lateral area. Design: Clinical prospective study. Materials: Sixty patients who underwent carotid endarterectomy were studied with continuous and simultaneous EEG and transcranial cerebral oximetry. Forty-three patients (72%) simultaneously underwent frontal and lateral transcranial cerebral oximetry. The lateral probe was only used in 17 patients. Methods: The percentage decrease of transcranial cerebral oximetry was calculated during cross-clamping. Using the EEG findings as the gold standard in order to detect cerebral ischaemia during carotid cross-clamping, the relationship with transcranial cerebral oximetry was described in terms of sensitivity, specificity and the area under the curve in a receiver operating characteristic curve. Results: The 95% confidence interval of the area under the curve of the receiver operating characteristic of the lateral probe was 0.61–1.00 and that of the frontal probe was 0.65–1.00; therefore there is virtually no difference between the two methods. In 18% of the cases the lateral transcranial cerebral oximetry was hindered by practical failures. Conclusion: Considering the lack of additional information and the practical problems experienced with the lateral probe, it was concluded that transcranial cerebral oximetry with a single frontal probe is a practical non-invasive monitoring system and is at least as representative for monitoring cerebral ischaemia during carotid cross-clamping as a lateral probe.