Cerebral monitoring by means of oximetry and somatosensory evoked potentials during carotid endarterectomy

Cho, Hun; Nemoto, Edwin M.; Yonas, Howard; Balzer, Jeffrey; Sclabassi, R.J.

doi:10.3171/jns.1998.89.4.0533

Cited by 95 publications

(50 citation statements)

References 14 publications

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“…In adults, normal TOI values have been reported to range from 65% to 85%. 14,36 -41 Although a number of authors have compared NIRS with other techniques such as jugular bulb oxygen saturation (SjO 2 ), transcranial Doppler ultrasonography and somatosensory-evoked potential 15,37,[42][43][44][45][46][47][48][49][50][51][52][53][54][55][56] or with neurologic events, few have attempted to define an absolute threshold for ischemia. 13,14,16,17,46,[57][58][59] Most studies of this type using NIRS make no attempt to correct for extracranial contributions to signal changes.…”

Section: Discussionmentioning

confidence: 99%

Tissue Oxygen Index

Al-Rawi

Kirkpatrick

2006

Stroke

149

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Background and Purpose-To date, the clinical application of near infrared spectroscopy in the adult brain has been limited. The NIRO 300 (Hamamatsu Photonics) provides a continuous measurement of tissue oxygen index (TOI) using spatially resolved spectroscopy. Although TOI reflects cerebral oxygenation to a high degree of sensitivity and specificity, to become a useful clinical tool, thresholds for cerebral ischemia need to be defined. This study has attempted to identify a quantifiable TOI threshold for ischemia in the adult brain. Methods-One hundred sixty-seven patients undergoing carotid endarterectomy were studied. The NIRO 300 was incorporated into an established multimodal monitoring system enabling observations of cerebral hemodynamic changes under highly controlled conditions. Changes in TOI (%⌬TOI) on clamping the internal carotid artery were compared with intracranial blood flow (middle cerebral artery flow velocity) and cerebral function monitoring to identify and quantify periods of cerebral ischemia. Results-Significant correlation was seen between changes in middle cerebral artery flow velocity and ⌬TOI on clamping (rϭ0.74, Pϭ0.0001). Thirty-one patients showed cerebral ischemia on internal carotid artery clamping as defined by a sustained fall in cerebral function monitoring. A threshold for %⌬TOI of Ϫ13 was identified, above which no patients showed any evidence of ischemia on clamping. This threshold provided 100% sensitivity and 93.2% specificity for patients satisfying the preset criteria for cerebral ischemia. Conclusions-These data demonstrate the potential to identify TOI-quantified thresholds for cerebral ischemia in the adult brain and thus improve the clinical use of near infrared spectroscopy. Our observations have defined a drop in TOI (13%) that can be adopted as a threshold for severe cerebral ischemia with high sensitivity and specificity. Key Words: carotid endarterectomy Ⅲ cerebral ischemia Ⅲ near infrared spectroscopy Ⅲ spatially resolved spectroscopy Ⅲ tissue oxygen index O ptical methods based on near-infrared spectroscopy (NIRS) can be used to monitor hemodynamic variables in the clinical setting. 1 Applications include monitors of fetal physiology, 2-4 during cardiac surgery, 5,6 muscle function, 7-10 and neonatal, 11 pediatric, 12 and adult brain. [13][14][15][16][17][18][19] A number of NIRS instruments are now available that detect changes in optical attenuation from several wavelengths of light, and although a variety of algorithms have been applied to attempt quantification, accuracy of these instruments remains a concern.The NIRO 300 (Hamamatsu Photonics) provides a continuous online measurement of tissue oxygen index (TOI) using spatially resolved spectroscopy. 20,21 We have previously determined that TOI reflects cerebral oxygenation to a high degree of sensitivity and specificity during carotid surgery, 20 an indication that NIRS can show clinically relevant estimations of cerebral hemodynamic and oxygen changes in the adult head (Figure 1). However, there are no da...

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Section: Discussionmentioning

confidence: 99%

Tissue Oxygen Index

Al-Rawi

Kirkpatrick

2006

Stroke

149

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“…Thus, the issue of extracranial contamination in SO 2 monitoring remains a topic of considerable debate, particularly when SO 2 monitoring is used for recognition of cerebral ischemia during ICA and external carotid artery clamping (Duncan et al, 1995;Kirkpatrick et al, 1995;Beese et al, 1998;Samra et al, 2000;Takeda et al, 2000). Most investigators have also observed that the absolute changes of SO 2 after ICA clamping were highly variable from patient to patient (Beese et al, 1998;Cho et al, 1998;Grubhofer et al, 2000;Samra et al, 2000) and that the specificity of these values are not sufficient for satisfactory identification of patients suffering from severe cerebral ischemia during ICA clamping (Beese et al, 1998;Grubhofer et al, 2000). However, other investigators suggest that the intersubject variability in the absolute changes of SO 2 could be addressed by normalizing the data and recording the decrease in SO 2 after ICA clamping as a percentage of preclamp value (Cho et al, 1998;Samra et al, 2000).…”

Section: Discussionmentioning

confidence: 99%

“…Most investigators have also observed that the absolute changes of SO 2 after ICA clamping were highly variable from patient to patient (Beese et al, 1998;Cho et al, 1998;Grubhofer et al, 2000;Samra et al, 2000) and that the specificity of these values are not sufficient for satisfactory identification of patients suffering from severe cerebral ischemia during ICA clamping (Beese et al, 1998;Grubhofer et al, 2000). However, other investigators suggest that the intersubject variability in the absolute changes of SO 2 could be addressed by normalizing the data and recording the decrease in SO 2 after ICA clamping as a percentage of preclamp value (Cho et al, 1998;Samra et al, 2000). Such normalization would account for intersubject variability as well as allow comparisons between different investigations.…”

Section: Discussionmentioning

confidence: 99%

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Cerebral Hyperperfusion after Carotid Endarterectomy is Associated with Preoperative Hemodynamic Impairment and Intraoperative Cerebral Ischemia

Komoribayashi

Ogasawara

Kobayashi

et al. 2005

J Cereb Blood Flow Metab

106

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The aim of this study was to investigate whether postoperative hyperperfusion is associated with preoperative cerebral hemodynamic impairment due to chronic ischemia and with acute cerebral ischemia during clamping of the internal carotid artery (ICA) during carotid endarterectomy (CEA). Transcranial cerebral oxygen saturation (SO 2 ) was monitored intraoperatively using near-infrared spectroscopy in 89 patients undergoing CEA for ipsilateral ICA stenosis ( > 70%). Cerebral blood flow (CBF) and cerebrovascular reactivity (CVR) to acetazolamide were also measured using single photon emission computed tomography (SPECT) before CEA. In addition, CBF was measured immediately after CEA and on the third postoperative day. Hyperperfusion (CBF increase > 100% compared with preoperative values) was observed immediately after CEA in 10 of 18 patients (56%) with reduced preoperative CVR. Also, post-CEA hyperperfusion was observed in nine of 16 patients (56%) whose SO 2 during clamping of the ICA decreased to less than 90% of the preclamping value. Logistic regression analysis showed that reduced preoperative CVR and reduced SO 2 during ICA clamping were significant independent predictors of the development of hyperperfusion immediately after CEA. In fact, all patients with reduced preoperative CVR and reduced SO 2 during ICA clamping developed post-CEA hyperperfusion, and two of these patients developed cerebral hyperperfusion syndrome. These data suggest that development of cerebral hyperperfusion after CEA is associated with preoperative hemodynamic impairment and intraoperative cerebral ischemia.

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“…Cerebral oxygen saturation values were evaluated with regard to three cutoff points that should reflect critically low oxygenation. The incidence and duration of decrease in rSO 2 values (cerebral desaturation) were recorded as any of the three following values for more than five consecutive minutes; (1) decrease in absolute rSO 2 values to less than 50%, (2) decrease in absolute rSO 2 values to less than 40%, and (3) a 20% decrease compared to individual baseline value [11].…”

Section: Physiologic Variables Measurementmentioning

confidence: 99%

Prediction of cognitive dysfunction and patients’ outcome following valvular heart surgery and the role of cerebral oximetry

Hong

Shim

Choi

et al. 2008

European Journal of Cardio-Thoracic Surgery

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Cerebral monitoring by means of oximetry and somatosensory evoked potentials during carotid endarterectomy

Abstract: The results indicate that at least as measured with the INVOS3100A instrument, a decrease in rSO2 of -10 or more or a decrease below an rSO2 of 50 is indicative of cerebral ischemia of sufficient severity to decrease the amplitude of SSEPs.

Cited by 95 publications

References 14 publications

Tissue Oxygen Index

Tissue Oxygen Index

Cerebral Hyperperfusion after Carotid Endarterectomy is Associated with Preoperative Hemodynamic Impairment and Intraoperative Cerebral Ischemia

Prediction of cognitive dysfunction and patients’ outcome following valvular heart surgery and the role of cerebral oximetry

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